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1PALATABILITY AND CHEMICAL DEFENSESOF MACROALGAE IN THE ANTARCTICPENINSULAAmsler, C. D.1,∗, Amsler, M. O.1, McClintock, J. B.1,Iken, K. B.1, Hubbard, J. M.1 & Baker, W. J.21Department of Biology, University of Alabama atBirmingham, Birmingham, AL 35294-1170; 2Departmentof Chemistry, University of South Florida, Tampa, FL33620, USA

We examined palatability of 37 species of nonen-crusting macroalgae from the Antarctic Peninsula.This represents approximately 30% of the entireantarctic macroalgal flora and 75% of the 49nonencrusting species we collected. Organic extractsfrom most species were also prepared and mixedinto artificial foods. We examined palatability usingfeeding bioassays with three common, macroalga-consuming animals (an omnivorous antarctic rock-fish, Notothenia coriiceps; an omnivorous sea star,Odontaster validus; and a herbivorous amphipod, Gon-dogenia antarctica). Thallus pieces from 23 of 34macroalgal species tested with the fish (68%) wererejected. Of the 23 species rejected as thallus, or-ganic extracts of 16 were bioassayed using the fishwith 9 (56%) unpalatable. Thallus pieces from 21 of36 macroalgal species tested with the sea star (58%)were rejected. Of the 21 species rejected as thal-lus, organic extracts of 20 were bioassayed using thesea stars and 14 (70%) were unpalatable. Overall,28 of the 37 species assayed as thallus (76%) wererejected by either or both the fish and sea stars.The amphipod assay was not suitable for use withthallus but was utilized with organic extracts of 23macroalgal species that were rejected as thallus byeither or both the fish and sea stars. Of these,14 (61%) of the species’ extracts were rejected bythe amphipods. Unpalatability was highest amongthe brown algae examined with only an ephemeral,ectocarpoid species not rejected as thallus out of10 species tested. Of the remaining nine brownalgal species, six of seven tested were also un-palatable as extracts, including all the ecologi-cally dominant, perennial species in the area. Weconclude that unpalatability to herbivores is com-mon in antarctic macroalgae and that chemicaldefenses may play an important role in the un-palatability of many algal species (NSF OPP9814538,OPP9901076).

2DINOFLAGELLATE GENOMICS: RESULTSFROM AN EST APPROACHBachvaroff, T. R.1,∗, Herman, E. M.2 &Delwiche, C. F.11Cell Biology and Molecular Genetics, University ofMaryland, College Park, MD 20742; 2Soybean GenomicImprovement Laboratory, USDA/ARS, Beltsville, MD20705, USA

Dinoflagellates are enigmatic protists with odd nu-clear features, interesting plastid gene arrangementsand a proclivity for endosymbiotic relationships. Rel-atively little molecular work has been done on di-noflagellates, and only a handful of genes have beencharacterized in these organisms. We have begun anExpressed Sequenced Tag (EST) project with the aimof collecting plastid targeted but nuclear encodedgenes from peridinin-containing dinoflagellates. Thisprovides an opportunity to understand the integra-tion of endosymbiont genes into the host cell. Our se-quencing effort has produced about 1000 unique ESTsfrom a Gonyaulax polyedra cDNA library obtained fromDavid Morse. Of the 1535 total ESTs (72%, >400 bp),466 sequences were identifiable by BLAST with a bitscore above 50. The most abundant transcript is theperidinin–chlorophyll-binding protein, which consti-tuted 3% of the clones. More recently, we began se-quencing from an Amphidinium carterae cDNA librarymade in our laboratory. This provides insight into ex-pression patterns and is a resource for other workersin the field. Several clearly identifiable plastid geneshave been found and preliminary analysis confirmsthe chromophyte, and therefore, tertiary origin of theperidinin plastid.

3ALGAL STIMULATION OF THE BERKELEY PITLAKE SYSTEMBartkowiak, B. & Mitman, G. G.∗

Montana Tech University of Montana, 1300 West ParkStreet, Butte, MT 59701, USA

This study was conducted to evaluate four speciesof algae (Chromulina freiburgensis Dofl., Chlorella ellip-soidea Gerneck, C. vulgaris Beijerinck, and Chlamy-domonas acidophila Negoro) isolated from an acid pitlake for their bioremediative potential. The BerkeleyPit Lake system, located in Butte, MT, USA is an aban-

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doned open-pit mine. As a result of acid rock drainagethe water in this pit is very acidic and contains highconcentrations of dissolved metals. First, optimal nu-trient levels for each species of algae were determined.Levels of nutrients tested include: 5, 10, 15 mg N/L,and 0, 3, 6 mg P/L. The experiment was conductedwith sterile filtered Berkeley Pit water. Next, eachspecies of algae were grown under optimal nutrientlevels and dissolved metal removal potentials wereexamined, using Inductively-Coupled Plasma–AtomicEmission Spectrometry (ICP–AES). In addition, fieldsampling was preformed to gain a better understand-ing of the microbial community within the pit. Finally,field parameters including, light, temperature, dis-solved oxygen, specific conductivity, redox potential,and turbidity were examined to determine the actualconditions for microbial growth within the Berkeleypit.

4PHYTOPLANKTON COMMUNITYCOMPOSITION IN THE TRI-LAKES AREA OFCENTRAL WISCONSIN, USABell, R. A.Department of Biology, University of Wisconsin – StevensPoint, Stevens Point, WI 54481, USA

Tri-Lakes (Upper and Lower Camelot, Sherwood, Ar-rowhead) in Adams County, WI, USA are man-madeimpoundments draining substantial agricultural landsand surrounded by considerable shoreline residen-tial development. The planktonic algal community, assampled from June to November 2000, was sparse-to-moderately dense, fairly diverse (69 genera from sixdivisions basin-wide), and unremarkable in taxonomiccomposition. All sites sampled displayed the generalalgal successional trends expected from northern-temperate, mildly eutrophic waters. These includedsparse but taxonomically diverse communities in thespring; a late spring pulse of diatoms; a late summerpulse of green algae; and a steadily increasing com-ponent of Cyanobacteria leading to their communitydominance by the end of the growing season. UpperLake Camelot (55 genera) best represented this pat-tern. Lower Lake Camelot (53 genera) had a largegreen algal pulse but only a small diatom pulse. LakeSherwood was the most taxonomically diverse body(63 genera) and had the most extreme pulses of di-atoms and greens. Lake Arrowhead had the lowesttaxonomic diversity (39 genera), was the most domi-nated by Cyanobacteria, and had only minor pulses ofdiatoms and greens. The algal communities indicatea mesotrophic to slightly eutrophic lake status. Con-

tinued agricultural and residential inputs of fertilizersand pesticides will likely exacerbate the cyanobacterialdominance leading to further reductions in aquatichealth and aesthetic values. Previous chemical treat-ment and macrophyte removal have achieved limitedsuccess, and might have altered algal community dy-namics. Remediation approaches that might improvewater quality include: reducing upstream inputs viasediment traps or lagoons; reducing in-lake nutri-ents via sediment removal; reducing residential inputsvia improved septic/sanitation systems; and shorelinevegetation filter strips.

5DESMIDS AND DINOFLAGELLATES OFECUADORCarty, S.∗ & Hall II J. D.Department of Biology, Heidelberg College, Tiffin, OH44883, USA

The freshwater flora of Ecuador is poorly known.This report provides preliminary information aboutthe freshwater Pyrrhophyta and two families in theChlorophyta. There has been some work on diatomsbut other groups remain unstudied. In June 2001,samples were collected as whole water or by using a10-mm plankton net from 52 locations in the inte-rior (Amazonian) and Andean regions and examinedwithin hours using a Swift field microscope. Nine ad-ditional samples from Ecuador have been providedby Dr Miriam Kannan. Amazonian sites consisted ofoxbow lakes along the Rio Shiripuno, and small pondsand lakes along the road from the river to Coca. An-dean sites were principally in the Cajas National Parknear Cuenca. Genera in the Closteriaceae includeClosterium, Gonatozygon, Spinoclosterium, and Penium.Desmidiaceae include Arthrodesmus, Bambusina, Cos-marium, Desmidium, Euastrum, Hyalotheca, Micrasterias,Pleurotaenium, Spondylosum, Staurastrum, Staurodesmus,Triploceras, and Xanthidium. Pyrrhophyta include Cer-atium, Gymnodinium, Peridinium, Sphaerodinium, andWoloszynskia.

6PHORMIDIUM RETZII (OSCILLATORIALES):GENOTYPIC VARIATION AND PHENOTYPICPLASTICITYCasamatta, D. A.1,∗, Vis, M. L.1 & Sheath, R. G.21Department of Environmental and Plant Biology, OhioUniversity, Athens, OH 45701; 2Provost Office, CaliforniaState University, San Marcos, CA 92096, USA

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Phormidium retzii is one of the most commonly en-countered lotic taxa in North America and has beenrecorded from a wide range of habitats worldwide.The genetic variability of this cosmopolitan, fresh-water cyanobacterium was assessed using gene se-quences and random amplified polymorphic DNA(RAPD) markers. Strains consistent with the mor-phological species circumscription were utilized fromBritish Columbia, Canada to Rio Claro, Costa Rica,and from Rhode Island to Washington State, USA.In addition, some strains were from geographicallyclose (<25 miles apart) sites. The 16S rRNA gene wassequenced for eight of the 12 strains. Sequence ho-mology ranged from 90.95 to 98.71. The nine RAPDprimers utilized yielded a total of 133 distinct bandsfrom the 12 strains. The strains were variously relatedand showed great variation in pairwise genetic dis-tances (0.23–0.83). Given the lack of sequence similar-ity, P. retzii as presently circumscribed most likely rep-resents several cryptic species not clearly distinguish-able with light microscopy of morphological charac-ters. This conclusion may explain the lack of correla-tion between geographic proximity and genetic simi-larity. To assess the level of environmentally inducedphenotypic plasticity of this taxon, one strain wassubjected to three different current velocity and nu-trient regimes (low, medium, and high) employingsix stream mesocosms. ANOVAs and Bonferroni mul-tiple comparison tests were performed with cell vol-umes, ratios of cell length : width and percent coverdata. Low nutrient treatments elicited significantly(P < 0.05) greater cell volumes and percent coverthan did high treatments. Furthermore, current ve-locity did not show any significant effect on cellmorphology. As such, it appears that a single strainis capable of wide morphological variability in re-sponse to some environmental conditions. The re-sults of these two studies have great implicationsin the utilization of cyanobacterial morphospeciesconcepts.

7GREEN ALGAL CONQUEST OF THE LAND:MANY CONQUESTS, ONE VICTORY?Chapman R. L.1,∗, Delwiche, C. F.2 &McCourt, R. M.31Department of Biological Sciences, Louisiana StateUniversity, Baton Rouge, LA 70803-4110; 2Departmentof Cell Biology and Molecular Genetics, Universityof Maryland, College Park, MD 20742-5815;3Academy of Natural Sciences, Philadelphia,PA 19103, USA

Life on earth originated in a wet world and remainedthere for millions of years until the first terrestrial in-vaders made their initial forays into a new and un-exploited terrestrial habitat. Although cyanobacteria,and perhaps fungi as well, were important participantsin the conquest of the land, it was the evolution greenalgae into the initial land plants that started amaz-ing evolution and diversification the terrestrial floraand fauna with which we are now familiar. Given theparadigm that life arose in the sea, it is perhaps surpris-ing to find that freshwater green algae – not marineforms – were the successful conquerors, i.e. the algaethat gave rise to the land plants. The first land colo-nizers were, of necessity, primary producers (i.e. foodfor organisms that arrived or evolved later) and werelikely to have been cyanobacteria (blue-green algae),followed by green algae (at least four separate inva-sions) and fungi, which also made a successful assaulton land together with algae in the form of lichens. Thesymposium will survey recent studies on these groupsand their habitats, and describe how these colonizerschanged and were changed by adaptations to the new,dry world. It will explore the question: ‘Why did onlyone group of terrestrial green algae give rise to theland plants?’ The success of these colonizers is rele-vant to all subsequent terrestrial life (including our-selves), as well as the search for extraterrestrial life,which, if it exists, is presumed to have begun in anaquatic environment.

8PHYLOGEOGRAPHY OFBATRACHOSPERMUM HELMINTHOSUM(RHODOPHYTA) IN NORTH AMERICAChiasson, W. B., Machesky, N. J. & Vis, M. L.∗

Department of Environmental and Plant Biology, OhioUniversity, Athens, OH 45701, USA

The freshwater red alga, Batrachospermum helmi-nthosum, is distributed primarily in streams of east-ern North America. Although it is often an abun-dant and conspicuous component of the algal florafor many streams, little is known about the genetic re-lationship among populations throughout its range.The purpose of our study was to elucidate geographicpatterns among populations to gain insight into thebiogeographic distribution of this species and possi-ble modes of dispersal. Individuals were sampled in13 stream segments as follows: four locations in Ohio,two locations in Michigan and one location each inIndiana, North Carolina, Tennessee, Louisiana,Rhode Island, Massachusetts and Connecticut. Themitochondrial spacer region (371 bp) between the

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COX2 and COX3 genes was chosen because it is vari-able among individuals. This region was sequencedfor 15 individuals from each location. Thirteen hap-lotypes were identified among the 13 locations withmost locations having one or two haplotypes. Two ofthe haplotypes were dominant being recorded fromsix of the streams. The Indiana, Louisiana and firstMichigan population had a unique haplotype. Thesecond Michigan and fourth Ohio populations shareda unique haplotype. The Tennessee population hadfour haplotypes, three of which were closely relatedbut the fourth haplotype was not and linked to thehaplotypes from Michigan and Ohio. The relation-ships among these populations are very complex butthere may have been a recent dispersal event via birdsamong various streams.

9CHARACTERIZATION OF MACROALGALEPIPHYTES ON THALASSIA TESTUDINUM INTAMPA BAY, FLORIDACho, T. O.1,∗, Fredericq, S.1 & Yates, K. K.21Department of Biology, University of Louisiana atLafayette, Lafayette, LA 70504-2451; 2US GeologicalSurvey 600, 4th Street South, St. Petersburg, FL 33701,USA

Blooms of seagrass epiphytes have potentially impor-tant economic and ecological consequences in TampaBay, one of the Gulf of Mexico’s largest estuaries.As part of a Tampa Bay pilot study to monitor theimpact of environmental stresses, precise character-ization of epiphyte diversity is required for efficientmanagement of affected resources, and thus may beused as a rational basis for assessment of ecosystemhealth. Fixed monitoring sites were selected north ofPort Manatee, composed of dense and sparse Tha-lassia testudinum seagrass sites. A total of 13 epiphyticspecies encompassing green, brown and red macroal-gae were manually collected in May 2001 from denseseagrass beds versus nine species from sparse beds. Epi-phytes only collected in the dense beds were Enteromor-pha flexuosa, Sphacelaria rigidula, Ceramium byssoideum,and Herposiphonia tenella; epiphytes only occurringin the sparse beds were Griffithsia and Stylonema al-sidii. A correlation seems to emerge among attach-ment mode of epiphyte to host, presence of corti-cation and epiphyte length. A main goal of this on-going study is the determination of indicator speciesfor both healthy and stressed seagrass bed environ-ments using both taxonomic and gene-sequencingtechniques.

10NEW SYSTEMATIC INSIGHTS IN THECERAMIUM SINICOLACOMPLEX : RESURRECTIONOF C. INTERRUPTUM S. & G. (CERAMIACEAE,RHODOPHYTA)Cho, T. O.1,∗, Fredericq, S.2, Murray, S. N. &Boo, S. M.31Department of Biology, University of Louisiana, Lafayette,LA 70504, USA; 2Department of Biology, California StateUniversity, Fullerton, CA 92834, USA; 3Department ofBiology, Chungnam National University, Daejon 305-764,Korea

Setchell & Gardner (1924) provided a taxonomictreatment for the genus Ceramium from lower Califor-nia and the Gulf of California, Mexico, in which theydescribed several new species, including C. sinicola S. &G. described from Ensenada, BCN and C. interruptumS. & G. described from the vicinity of La Paz, BCS. Thelatter was later reduced to variety rank in C. sinicolabyDawson (1950), a taxonomic decision that has subse-quently been widely adopted. Phylogenetic analysesinferred from three molecular markers (chloroplast-encoded rbcL, the RUBISCO spacer, and nuclearencoded SSU rDNA) from recent collections fromthe Pacific North-west (California, Oregon) and theGulf of California reveal a well supported assem-blage of three corticated taxa: C. codicolaJ. Ag. 1894,C. sinicola and C. sinicola var. interruptum. Sequence di-vergence values among the three taxa are sufficientto warrant separate species ranking; hence, we rein-state C. interruptum as a widely distributed epiphytefor the region. C. sinicolais more closely related toC. codicolathan to C. interruptum, with the former tworestricted to the host Codium. The molecule-based re-lationships are congruent with evolutionary trends incortication pattern and attachment mode.

11PHYTOPLANKTON OF A MISSISSIPPI RIVERWATERSHED IN COASTAL LOUISIANACiugulea, I. I.1, Waters, D. A.2,∗, Day J. R. J. W.3 &Chapman, R. L.21Department of Botany and Microbiology, University ofBucharest, Romania; 2Department of Biological Sciences,3Department of Oceanography and Coastal Sciences,Louisiana State University, Baton Rouge, LA, USA

In July–August 2001, phytoplankton samples were col-lected from a coastal marsh south of New Orleans,LA. This wetland area is usually cut off from the Mis-sissippi River by levees and other flood control devices,but periodically the Caernarvon Diversion is openedto allow fresh river water to flow into the marsh. As

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part of a larger project, the present study seeks todetermine the affect the periodic input of freshwa-ter has on phytoplankton dynamics in the CaernarvonDiversion watershed. The first phase of the project -collecting and identifying algae during the summerwhen the Caernarvon Diversion is kept closed - hasbeen completed. A total of 168 species from 76 generarepresenting 8 phyla were identified and digital im-ages recorded. Little or no previously published dataon the taxonomy and ecology of phytoplankton fromthis area are available. Sampling in spring 2002, whenthe diversion is open, will allow comparative analy-sis of phytoplankton composition and productivity.In a collaborative study, the phytoplankton data willbe combined with information on nutrients, chloro-phyll a, turbidity, salinity, etc. and used in a model todemonstrate how the ecosystem is affected by the di-version. Also, a database of digital images is available athttp://www.chapman.lsu.edu/digitalalgae. In addi-tion to the taxonomic identification data and images,the site will eventually include physico-chemical andGIS data on the collection sites. Supported in part bya grant from the Office of Sea Grant Development atLSU.

12ORIGIN AND EARLY EVOLUTION OF PLANTBODY SYMMETRY AND GRAVITY RESPONSESCook, M. E.1,∗ & Graham, L. E.21Department of Biological Science, Illinois State University,Campus Box 4120, Normal, IL 61790-4120; 2Departmentof Botany, University of Wisconsin, 430 Lincoln Drive,Madison, WI 53706-1381, USA

Land plant bodies exhibit both apical–basal and radialsymmetry, and they are able to detect and respondto gravitational forces. These attributes were, likelyimportant factors in the success of earliest plants onland. This study focuses on features of charophyceangreen algae likely to have been pre-adaptive to earlyestablishment of plant symmetry and gravitational re-sponses, though most modern charophyceans occupyaquatic habitats where the buoyancy of water counter-acts the effects of gravity. Trait mapping suggests thateven the earliest-divergent modern members of thestreptophyte clade have bodies whose symmetry de-parts significantly from the spherical condition, andthat cellular mechanisms defining aspects of radialsymmetry and polarized tip growth originated early.Genes, cell biological approaches, and taxa are iden-tified for which further exploration is likely to illu-minate early evolution of plant body symmetry andgravity responses.

13EFFECTS OF SAMPLING SCALE AND ANALYSISMETHOD ON PERCEPTIONS OFPHYTOPLANKTON SPECIES ASSOCIATIONSDavis, B. E.1,∗, Interlandi, S. J.2, Kilham, S. S.2 &Theriot, E. C.11Integrative Biology, University of Texas at Austin, Austin,TX 78712; 2School of Environmental Science, Engineering,and Policy, Drexel University, Philadelphia, PA 19104,USA

Phytoplankton associations generally are identified bynonrandom co-occurrence of phytoplankton species,and are considered to be a result of similar speciesresponse to properties of the environment. Becausean association is characterized by co-occurrence ofspecies across samples, or synchrony of the abundanceof species over time, we proposed that the percep-tion of phytoplankton association is subject to spa-tial and temporal sampling scale and analysis method.We investigated this using an intensive phytoplanktondataset from three lakes of the Greater YellowstoneEcosystem, with particular concentration on Asteri-onella formosa (AF) and Aulacoseira subarctica (AS). Wecompared numerical analyses, including Fager anal-ysis of recurrent groups, rank correlation, and othermeasures of synchrony, for differences in assessmentof co-occurrence. The analyses were conducted on theentire dataset, and then the dataset was reduced toassess the effect of different spatial or temporal sam-pling regimes on apparent association. While the twodiatom species significantly co-occurred across sam-ples, assessment of synchrony was affected by analysismethod and sampling regime. AF and AS abundancewere positively correlated across lakes and within eachlake, but peaks in abundance of the two species did notsignificantly coincide over time. In addition, speciesabundance were negatively correlated across depths,and we argue that this is significant to the autecologyof each species. These results indicate that the percep-tion of phytoplankton association may simply be anartifact of the limits of our understanding of the dis-tribution and physiology of the organisms.

14A GUIDE TO THE SEAWEEDS OF FLORIDADawes, C. J.1,∗ & Mathieson, A. C.21Department of Biology, University of South Florida,Tampa, FL 33620; 2Department of Plant Biology,University of New Hampshire, Durham, NH 03824, USA

A review of Florida seaweeds indicates a highly di-verse flora within a large coastal zone (over 700 km)

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spanning more than 7◦ of latitude, containing tropi-cal, subtropical, and temperate communities. Surpris-ingly, there have been relatively few detailed floristicstudies of Florida seaweeds, except for the Florida Keysand on the east coast. The patterns are a reflection ofthe early predominance of winter visitors and lack ofresident phycologists. The seaweeds of the west coastof Florida were virtually ignored until the 1950s. Weestimate that the state’s seaweed flora consists of atleast 670 taxa including 219 green, 97 brown, 349 redalgae, and at least 3 species of Vaucheria. Such a compi-lation is significantly higher than the numbers of taxarecorded for Florida by Taylor (1960), as well as thosefor North Carolina (i.e. Schneider & Searles, 1991),and Caribbean reefs (Littler & Littler, 2000). The ma-jority of Florida seaweeds have tropical/Caribbeanaffinities, although a significant temperate compo-nent also occurs, presumably reflecting the influenceof the northern floras of the Gulf of Mexico and south-eastern coast of the US. The tropical nature of thestate’s flora is supported by the R/P and R + C/P in-dices of Feldman (1937) and Cheney (1997) with theseratios being 3.6 and 5.8, respectively. Florida’s sea-weed diversity is enhanced by the extensive salt marshand seagrass communities of the west coast, plus thecoral reef habitats of the Florida Keys. The present re-view summarizes several important historical studies,conspicuous geographic patterns, the type of commu-nities, and the structure of a guide to the seaweedsof Florida. The guide will also serve as a historicalreference for possible anthropogenic impacts in thefuture.

15ONE SMALL STEP: WHY DID THECHAROPHYTES HAVE THE RIGHT STUFF?Delwiche, C. F.1,∗, Karol, K. G.1 & McCourt, R. M.21Cell Biology and Molecular Genetics, University ofMaryland, College Park, MD 20742; 2Department ofBotany, Academy of Natural Sciences, Philadelphia, PA19103, USA

The origin and evolution of land plants (i.e. em-bryophytes) represents one of the seminal events inthe history of life on earth. When the land plant lin-eage took hold upon the continents, there were pro-found changes in the global environment includingdramatic modification of the erosion regime, corre-lated changes in marine nutrient inputs, and strikingfluctuations in atmospheric chemistry. These changestook place not only because of the ability of landplants to survive on land, but also because their struc-ture and physiology permitted them to make efficient

use of resources, anchor themselves effectively and inso doing stabilize the substrate and permit the for-mation of modern soils, and maintain metabolic ac-tivity for long periods of time even in the absenceof rainfall and surface moisture. Molecular phyloge-netic analyses show the order Charales is the sistergroup to all land plants, with the Coleochaetales sis-ter to the land plant/Charales lineage. Thus, in avery real sense, the embryophytes are ‘drier algae.’Many groups of green algae live in the terrestrial en-vironment, but only one of these – the land plants –has radiated into a wide range of habitats. It is notknown why the land plant lineage has been so suc-cessful. Traits that are likely to have played a role intheir success include cell wall biochemistry, desicca-tion resistance and tolerance, structural complexity,and various reproductive strategies. In all probability,the success of the land plant lineage was not the resultof a single ‘key innovation’, but an emergent prop-erty resulting from complex interactions among theseand other features of the lineage. Comparative studyof the properties of diverse aquatic and terrestrial al-gae can be used to identify properties that were im-portant in the colonization of the land and how theyinteract.

16DIVERSITY OF FUSIFORMMICROCHLOROPHYTE ALGAE FROM ITASCASTATE PARK, MINNESOTADimmer, S. K.∗, Dean, M., Fawley, M. W. &Fawley, K. P.Department of Biological Sciences, North Dakota StateUniversity, Fargo, ND 58105, USA

Through the use of molecular techniques, severaldifferent types of fusiform and twisted-fusiform mi-crochlorophyte algae (Monoraphidium, Ankistrodesmus,etc.) have been characterized from samples takenfrom lakes and ponds of Itasca State Park, MN. PCR–RFLP analysis of 18S ribosomal RNA genes was usedto categorize 29 different isolates from the Itasca StatePark lakes into nine different types. The 18S riboso-mal DNA sequences were determined for one isolatefrom each type for phylogenetic analysis. Light mi-croscopy was used so that morphological character-istics as well as molecular characteristics can be com-pared and contrasted. The morphological characteris-tics were consistent for each PCR–RFLP type. Furtherdiscussion will include comparisons of the distributionand diversity of these organisms from Itasca State Parkto those from Arrowwood National Wildlife Refuge,ND.

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17A TOTAL EVIDENCE APPROACH TO INFERRINGTHE PHYLOGENETIC RELATIONSHIPS WITHINAULACOSEIRA (BACILLARIOPHYTA)Edgar, S.∗ & Theriot, E.Section of Integrative Biology, University of Texas atAustin, Austin, TX 78713, USA

Phylogenies provide the context in which hypothe-ses about character evolution can be tested. But thephylogenetic understanding of many diatom taxa, in-cluding some of the more spatially and temporallyubiquitous genera, is insufficient to fruitfully pursuequestions about character evolution within them. Con-sequently, we have estimated the phylogeny of Aula-coseira using a combination of nucleotide sequencedata and data derived from morphological charac-teristics of the silica cell wall. In addition to the useof traditional ‘discrete’ or ‘qualitative’ morphologi-cal characters, we have assessed the use in our cladis-tic analyses of ‘continuous’ or ‘quantitative’ charac-ters, including descriptors of the ontogenetic trajec-tories of these characters over a species’ life cycle (sizerange). Also, molecular characters gathered from achloroplast genome marker (rbcL) as well as a nucleargenome marker (18S rRNA) were used simultaneouslyin the cladistic estimation of the phylogeny of approxi-mately 12 species of Aulacoseira. In order to have morethorough taxon sampling for a better estimate of phy-logeny, we included several fossil species, as well astaxa where cultures were unavailable, by utilizing themorphologically based characters despite the absenceof molecular characters for these taxa.

18POST-EUROPEAN SEDIMENTATION ANDNUTRIENT LOADING IN LAKE ST. CROIX: ANATURAL IMPOUNDMENT ON THE ST. CROIXRIVER, USAEdlund, M. B.1,∗, Triplett, L.1,2 & Engstrom, D. R.11St. Croix Watershed Research Station, Science Museum ofMinnesota, 16910, 152nd St. N., Marine on St. Croix,MT 55047; 2Department of Geology, LimnologicalResearch Center, University of Minnesota, Minneapolis,MT 55455, USA

The final 37 km of the St. Croix River were natu-rally dammed by the Mississippi River to form LakeSt. Croix approximately 9500 years ago. The St. CroixRiver is currently regarded as having ‘exceptionalresource value’, as one of the least impacted largeMidwest river systems. Twenty-four 2-m piston coreswere recovered in 1999–2001 from Lake St. Croix sub-basins to identify post-European settlement signals of

land use, trophic change, and sedimentation using awhole-basin approach to reconstruct loading historyof nutrients, sediments, heavy metals, and organics.Dating chronologies based on 210Pb inventories indi-cated both cores recovered a sediment sequence dat-ing from pre- and post-European settlement (c. 1850)in the St. Croix River basin. Select cores were sub-jected to magnetic susceptibility, loss-on-ignition, anddiatom microfossil analysis. Sedimentary increases inmagnetic susceptibility were indicative of increasederosion and transport of ferromagnetic mineral grainsdue to initiation of settlement, logging, and agricul-tural activities in the basin. A three-fold increase insediment accumulation began in the mid-1800s in thenorthern basin and by 1900 in the southern basin.Diatom accumulation increased 20–50-fold since set-tlement with a shift from benthic- to planktonic-dominated assemblages. Simultaneous with the assem-blage shift were the introduction and establishment ofmany planktonic diatoms considered ubiquitous indi-cators of eutrophy. The fossil diatom assemblages werefurther analyzed using weighted-averaging calibrationand reconstruction of historical water column totalphosphorus (TP). Reconstructed TP values showedthat water column nutrient values have increased 2.5–3-fold since presettlement times. Presettlement valuesof about 0.02 mg/L TP were found in both cores withTP increases beginning c. 1910 and especially dra-matic increases after World War II. Modern recon-structed TP values (about 0.055 mg/L) were similarto TP concentrations reported from monitoring dur-ing the last few decades; however, the river was clearlyimpacted well before monitoring efforts were begun.

19PHOSPHATASE EXPRESSION BY CHLORELLAVULGARIS (CHLOROPHYCEAE) IS MEDIATED BYINTERNAL PHOSPHORUS LEVELS ANDEXTERNAL pHEvens, T. J.∗ & Koenig, R.US Department of Agriculture, Agricultural ResearchService, Southern Regional Research Center, New Orleans,LA 70124, USA

Phosphorus has been implicated as one of thecausative agents of the eutrophication of lacustrine,estuarine and coastal waters. One of the major inputsof phosphorus into these waters comes from agricul-tural nonpoint sources in the form of dissolved or-ganic phosphorus (DOP). In order to better under-stand how DOP may directly impact the microalgalcommunity structure, it is necessary to understand thephysiology of DOP uptake and utilization. To this end,cultures of Chlorella vulgaris were grown in custom pho-

8 ABSTRACTS

tobioreactors in acid (pH 5.5) and alkaline (pH 7.5)media under phosphate replete and starved condi-tions in order to determine the types and triggers ofphosphatase expression by this organism. Analysis ofdifferential phosphatase expression during phosphatestress indicates that cultures of C. vulgaris grown underalkaline conditions derepressibly express two alkalinephosphatases, while cultures grown under acid con-ditions weakly express only one alkaline phosphatase.Analysis of internal and external phosphorus levels,whole-cell phosphatase activity and in-gel activity ofprotein extracts indicate that alkaline phosphatase ex-pression is further mediated by internal, as opposedto external, phosphorus levels.

20BIODIVERSITY AND ASSOCIATION OFDINOFLAGELLATES IN CORAL REEF RUBBLE,CARRIE BOW CAY, BELIZEFaust, M. A.Smithsonian Institution, 1210 Silver Hill Road, Suitland,MD 20746, USA

The species diversity and distribution of benthic di-noflagellates are illustrated from the back reef sandhabitats at Carrie Bow Cay. Sand appears an ideal en-vironment for nurturing a variety of species. Sand sup-ported blooms of toxic, nontoxic, and parasitic assem-blages of dinoflagellates. Morphology of dinoflagel-lates is illustrated in SEM and LM pictures; includingthe life cycle of a parasitic dinoflagellate’s vegetativestage, sporogenetic stages, and the morphology of thefeeding organelle. The feeding organelle of the pri-mary dinoflagellate cysts is a hold fast and a peduncle-like infestation tube, a ‘sucker organelle’, that insertsitself into copepod eggs. The parasitic dinoflagellatecontinues feeding on crustacean eggs since it is theonly food source during vegetative cell division withinthe cyst. This is the first observation of the presenceof parasitic dinoflagellates in shallow coral reef wa-ter. The study attempts to provide new knowledge ondinoflagellate associations and morphology of sand-welling species in the microscopic food web of shallowwarm tropical waters. Even, sand-inhabiting inverte-brates are not exempt from parasitic dinoflagellates.

21DIFFERENCES AMONG COCCOID GREENALGAL COMMUNITIES IN MINNESOTA ANDNORTH DAKOTA LAKESFawley, P. K.∗ & Fawley, M. W.Department of Biological Sciences, North Dakota StateUniversity, Fargo, ND 58105, USA

Very little is known about the diversity and distribu-tion of freshwater unicellular coccoid green algae.The simple morphology and small size of these or-ganisms make reliable identification extremely diffi-cult. Current hypotheses suggest that species of coc-coid algae are widely distributed, opportunistic organ-isms that are always present in aquatic systems. Thesehypotheses are based on the assumption that phy-toplankton communities include only one or a fewspecies of coccoid algae. We examined the diversityand distribution of green-colored autosporic coccoidalgae in Itasca State Park in Minnesota and Arrow-wood National Wildlife Refuge in North Dakota us-ing molecular techniques and light microscopy. Ourpreliminary results indicate a higher level of diversityof coccoid green algae than has been reported in re-gional flora. Contrary to current hypotheses, commu-nities of coccoid green algae vary among the differentlakes.

22DIVERSITY OF COCCOID ALGAE INMINNESOTA AND NORTH DAKOTA LAKESFawley, M. W.∗, Fawley, K. P. & Hoffman, M. J.Department of Biological Sciences, North Dakota StateUniversity, Fargo, ND 58105, USA

The coccoid algae (a.k.a ‘little green balls’) are im-portant primary producers in freshwater communi-ties, but very little is known about their diversity.This lack of knowledge results from the extremelysmall size and simple morphology of these organisms,which makes identification by light microscopy es-sentially impossible. However, molecular techniquesallow differentiation of taxa at various levels andcan ultimately lead to species identification. We haveisolated several hundred cultures of coccoid algaefrom lakes and ponds in Itasca State Park in north-western Minnesota and Arrowwood National WildlifeRefuge in central North Dakota. Many of these isolateshave been examined by light microscopy, 18S rDNAPCR–RFLP analysis, and 18S rDNA sequence analy-sis. In addition, some taxa with multiple isolates havebeen examined by rbcL and ribosomal RNA ITS se-quence analysis. Our results indicate a high level ofdiversity, including possible new species of Chlorella,Muriella, Pseudomuriella and Mychonastes, among oth-ers. We will discuss the results of our analyses, includ-ing implications for identification of taxa and higherlevel systematics. Supported by National ScienceFoundation Grants DBI-00703867, MCB-0084188 andDEB-0128952.

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23ASSESSING THE BIODIVERSITY OFMONORAPHIDIUM USING 18S rDNASEQUENCESFawley, M. W.1, Fawley, K. P.1 & Dean, M. L.2,∗1Department of Biological Sciences, North Dakota StateUniversity, Fargo, ND 58105; 28715 W. Mallard Ct.,Franklin, WI 53132, USA

The taxonomy of the genus Monoraphidium is uncleardue in part to the absence of morphological featuresto clearly distinguish one species from another. Phy-toplankton samples collected from lakes in the Ar-rowwood National Refuge in eastern North Dakotawere found to contain several morphological speciesof Monoraphidium. Eighteen Monoraphidium isolateswere examined with light microscopy and six morpho-logical species were identified. PCR–RFLP of the 18SrDNA was used to type the isolates. Following digestionby Hae III and Taq I, the 18S rDNA PCR–RFLP patternsindicated 10 different types. Presently, the 18S rDNAproduct is being sequenced for each of the 10 types. Byexamining morphological characters and 18S rDNAsequences, congruence between morphology and se-quence data may be compared. Also, because thereis a lack of morphological characters defining Mono-raphidium species, diversity within the 18S rDNA se-quences may aid in the taxonomy of the genus andits place within the Chlorococcales. Supported by Na-tional Science Foundation Grants MCB-0084188 andDBI-0070387.

24SPATIAL AND TEMPORAL DISTRIBUTION OFLIFE HISTORY VARIANTS IN THE RED ALGA,MASTOCARPUS PAPILLATUSFierst, J. L.∗, Kubler, J. & Dudgeon, S. R.California State University Northridge, 18111 NordhoffSt., Northridge, CA 91330, USA

We investigated small-scale spatial structure in Masto-carpus papillatus, a red alga with sexual and apomicticlife-history variants. Spatial structure and habitat par-titioning can facilitate the coexistence of ecologicallysimilar organisms, and in M. papillatus a large scalegeographic spatial division is well documented. Vari-ants of M. papillatus display geographic parthenogen-esis where sexual fronds are common south of SanFrancisco Bay and apomicts dominate north of SanFrancisco Bay. Although geographic parthenogenesisin M. papillatus is well-documented small-scale spatialstructure was not previously known due to the similarappearance of sexual and apomictic upright fronds.

We investigated whether sexual and apomictic frondsdiffered in their spatial distribution by sampling forvertical differences in intertidal height and horizontalpatchiness. Fronds were sampled when reproductiveand cultured for life history. We found sexual vari-ants were significantly aggregated at lower intertidalheights while apomicts were found throughout the in-tertidal range. Sexual fronds were strongly seasonaland reproduced October–December whereas apomic-tic fronds reproduced throughout the year. These re-sults parallel the large-scale geographic distributionwith apomicts inhabiting marginal areas, and sug-gest dispersal capability may also facilitate geographicparthenogenesis.

25MACROALGAE OF THE HAWAIIAN ISLANDS: 23ADDITIONAL STREAM SEGMENTSFilkin, N. R.1,∗, Sherwood, A. R.2 & Vis, M. L.11Department of Environmental and Plant Biology, OhioUniversity, Athens, OH 45701; 2Department of Botany,University of Hawaii, Manoa, HI, USA

The Hawaiian Islands are located 3700 km from thenearest continental land mass and as such providean interesting research opportunity to study fresh-water organisms intolerant of seawater. The freshwa-ter biota have been only partially studied with littleresearch on the stream macroalgae. The only previ-ous study to focus solely on stream macroalgae, re-ported 25 new species to the Hawaiian Islands from34 stream segments sampled. The purpose of ourstudy was to expand the sampling of streams to betterdetermine macroalgal distributions and species rich-ness. Twenty-three additional stream segments (sevenon Oahu, eight on Kauai and eight on Hawaii) weresampled for macroalgae. The physical and chemicalparameters of each stream were measured. Streamsegments ranged greatly in size from 1.2 to 40 min width. Water temperature was relatively uniform(about 21 ◦C) but other chemical parameters differedfrom site to site (pH 5.5–8.9, specific conductance 20–200 mS/cm). Mean species richness per stream seg-ment was 3.9 with one to eight species collected persegment. Ninety populations of 44 infrageneric taxawere identified from the Cyanobacteria (20), Chloro-phyta (18), Rhodophyta (3) and Chrysophyta (3). Themost abundant taxa were Spirogyra sp. 2, Audouinellapygmaea and Phormidium retzii. All three of these speciesare cosmopolitan. Twenty-two of the taxa are newrecords for streams in the Hawaiian Islands. The largepercentage (50%) of new taxa suggests that more re-search is needed to fully catalog the Hawaiian streammacroalgal diversity.

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26THE ECOLOGICAL SIGNIFICANCE OFMYCOSPORINE-LIKE AMINO ACIDS IN ALGAEFranklin, L. A.Smithsonian Environmental Research Center, P.O. Box 28,Edgewater, MD 21037, USA

The links among mycosporine-like amino acids(MAAs), algal physiological ecology, and the envi-ronment may be viewed from two sides. The UV-absorption spectra of MAAs make them prime candi-dates for UV-screening compounds, and indeed, nu-merous studies have shown that a high concentrationof MAAs is correlated with various degrees of protec-tion of cellular processes from UV damage. Thus, itmight be said that the structure of terrestrial, eulit-toral and sublittoral algal communities depends inpart on their ability to synthesize effective quantitiesof MAAs. Corollaries to this hypothesis might includethe proposition that those species incapable of syn-thesizing MAAs will be excluded from UV-containingenvironments, and that UV is necessary to trigger MAAsynthesis. However, a number of studies have demon-strated that triggers of MAA synthesis need not in-clude exposure to UV, but may include the relativeavailability of nitrogen, osmotic stress, or high levelsof photosynthetically active radiation. Furthermore,the response to these factors may vary as a function ofother environmental conditions. These issues will bediscussed with respect to elucidating the master switchfor MAA synthesis.

27BIOLOGICAL WEIGHTING FUNCTIONS FORTHE EFFECT OF UV RADIATION ON CARBONPARTITIONING IN MICROALGAEFranklin, L. A.∗ & Neale, P. J.Smithsonian Environmental Research Center, P.O. Box 28,Edgewater, MD 21037, USA

UV radiation clearly inhibits phytoplankton photosyn-thesis, with direct effects on both photosystem II andthe enzyme, Rubisco, that catalyses the first reaction ofthe photosynthetic carbon reduction cycle. The subse-quent partitioning of fixed carbon into macromolec-ular pools (carbohydrates, lipids, and proteins) is alsoaffected by UV exposure, although relative changes inallocation are not well-documented and vary consider-ably. The wavelength specificity of inhibition of pho-tosynthesis has been described by spectral weightingfunctions, or biological weighting functions (BWFs)that combine the effect of UV radiation with interac-tive effects of longer wavelengths. BWFs permit one to

compare the effects of different radiation sources orvarious ozone depletion scenarios. However, no dataare available from which BWFs for partitioning can bedetermined, as experimental techniques have variedwidely. These BWFs are essential for predicting the ef-fects of increased UV-B on other trophic levels, andfor analyzing the cost and benefit of synthesizing pro-tective compounds. Using a polychromatic approach,we are developing BWFs for the partitioning of 14Cin Thalassiosira pseudonana (3H) at photosyntheticallysaturating irradiance. We are comparing these func-tions to BWFs calculated from simultaneous measure-ments of primary productivity. We have found consis-tent differences in sensitivity to UV exposure amongthe pools, and are testing these differences for signif-icance using a variety of model and calculation ap-proaches.

28A SURVEY OF THE OFFSHORE MARINEMACROALGAE FROM THE NORTH-WESTERNGULF OF MEXICO HARD BANK COMMUNITIESFredericq, S.1,∗, Cho, T. O.1, Gavio, B.1, Gurgel, C.F.1, Hickerson, E.2, Lin, S. M.1, Lopez-Bautista, J.1,Phillips, N.1, Viguerie, M. & Wysor, B.11Department of Biology, University of Louisiana atLafayette, Lafayette, P.O. Box 42451, LA 70504-2451;2Flower Garden Banks National Marine Sanctuary, Bryan,TX 77803, USA

The upper north-western Gulf basin is characterizedby a relatively shallow but well-developed continen-tal shelf with an extensive system of mid- and outershelf hard banks formed on unique tectonically cre-ated salt diapirs of varying origin and composition.Observations done by our laboratory while partici-pating in monitoring cruises to the National MarineSanctuaries of the E and W Banks of the Flower Gar-dens (TX), Stetson Banks (TX), Sonnier Banks (LA)and dredging cruises off Louisiana reveal a surpris-ingly different floristic composition among the sites.Several range extensions, new macroalgal records forthe Gulf of Mexico, and new species imply a muchmore complex algal community than previously doc-umented. Our ongoing project includes the develop-ment of a modern taxonomic, phylogenetic and mor-phological database essential to informed manage-ment for preservation of biological diversity. It alsoprovides a framework of seasonal algal compositionagainst which long-term trends and anomalies in algaldistribution and health of the Gulf of Mexico can beassessed at future dates.

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29NEW INSIGHTS IN THE SYSTEMATICS OF THEPHYLLOPHORACEAE (GIGARTINALES,RHODOPHYTA)Fredericq, S.1,∗, Lopez-Bautista, J. M.1 & Moe, R. L.21Department of Biology, University of Louisiana atLafayette, Lafayette, LA 70504-2451; 2UniversityHerbarium, VLSB 2465, University of California, Berkeley,CA 94720-2465, USA

The Phyllophoraceae, consisting of about 100 speciesworldwide, stands out in exhibiting a wide spectrum ofunique life history types that makes it unusually inter-esting for assessing the phylogenetic importance of re-productive traits relative to classification criteria. Typeof life history and position of the reproductive struc-tures on the thallus have traditionally formed the basisfor separating 11 genera in the Phyllophoraceae; how-ever, phylogenetic analyses inferred from three setsof DNA sequences [chloroplast-encoded rbcL, nuclearlarge-subunit ribosomal RNA gene (LSU rDNA), andinternal transcribed spacer regions (ITS) of nuclearribosomal DNA], instead indicate a lack of correla-tion between type of life history and phylogenetic rela-tionships among the established taxa. This lack of cor-relation dramatically challenges all of the traditionaltaxonomy, and we will present a revised classificationfor the family that downplays life-history features. Thestudy will answer the question which morphologicalfeatures can be used as meaningful indicators of phy-logenetic relationships in the Phyllophoraceae. Theresults will also be addressed in light of global biogeo-graphic hypotheses for the family.

30THE DIVERSITY AND AVAILABILITY OFCAULERPA SPECIES FOUND IN RETAILAQUARIUM OUTLETS IN SOUTHERNCALIFORNIA, USAFrisch, S. M.∗ & Murray, S. N.Department of Biological Science, California StateUniversity, Fullerton, CA 92834, USA

Biological invasions are recognized as a serious threatto marine biodiversity. Within the last 2 years, inva-sive populations of Caulerpa taxifolia were found insouthern California’s coastal waters as well as in NewSouth Wales, Australia. In addition, two other sea-weeds (Undaria pinnatifida and Caulacanthus ustulatus)also appear to have recently invaded southern Cali-fornia’s warm temperate waters. The introduction ofC. taxifolia has attracted much attention because thisexotic seaweed is thought to have significantly altered

the structure of Mediterranean marine ecosystems fol-lowing its 1984 invasion. The southern California inoc-ulation of C. taxifolia is believed to have resulted fromthe release of aquarium specimens. Besides C. taxifolia,other species of Caulerpa being sold for aquariumuse also may have the potential to invade temper-ate waters. As a first step towards making this deter-mination, the availability (% frequency) of Caulerpaspecies being sold in southern California for aquar-ium use was ascertained. Fifty retail saltwater aquar-ium stores were visited in three southern Californiacounties between November 2000 and August 2001.Sixteen Caulerpa taxa were identified from the retailaquarium outlets. Caulerpa species were sold in 52%of these stores. C. taxifolia, ‘Mediterranean form’, wasoffered for sale in 10% of the visited stores; C. serrulatavar. hummii (18%), C. racemosa (14%), and C. racemosavar. lamourouxii (14%) were the most commonly soldspecies. These data indicate that the aquarium indus-try is bringing into the region other species of Caulerpabesides C. taxifolia. Some of these species may also havethe potential to invade temperate waters.

31PHYLOGENETIC ANALYSES OF NUCLEAR 18SrRNA GENE SEQUENCES INDICATE THAT THEMASTOPHOROIDEAE (CORALLINALES,RHODOPHYTA) IS A POLYPHYLETIC TAXONGabel, J.∗, Bailey, J. C. & Freshwater, D. W.Department of Biological Sciences and Center for MarineScience, UNC-Wilmington, 601 S. College Road,Wilmington, NC 28403, USA

Nuclear small subunit ribosomal RNA (18S rRNA)gene sequences were determined for six speciesrepresenting three genera classified within theMastophoroideae and also for two species of Amphi-roa (Lithophylloideae). These data were combinedwith previously published 18S rRNA sequences for 37other coralline species and analyzed to: (1) determinethe phylogenetic position of the Mastophoroideaewithin the Corallinales; and (2) examine relationshipsamong Hydrolithon, Metamastophora, Neogoniolithon,and Spongites. Trees derived from parsimony and maxi-mum likelihood analyses of these data indicate that theMastophoroideae is not monophyletic. Instead, ourdata suggest that group is polyphyletic and includesspecies belonging to three (or more) distinct evo-lutionary lineages. The nongeniculate genus Neogo-niolithon is resolved as sister to the geniculate sub-family Corallinoideae. Hydrolithon is resolved as sis-ter to the geniculate genus Metagoniolithon, an Aus-tralian endemic. In turn, Spongites is positioned at the

12 ABSTRACTS

base of a clade including Hydrolithon/Metagoniolithonas well as species classified in the Lithophylloideae.Finally, Metamastophora is placed in a well supported,but isolated, position as sister to all other taxa bear-ing uniporate tetrasporangial conceptacles. Our re-sults imply that some reproductive and vegetative char-acters among the suite of features used to delimitthe Mastophoroideae were acquired independentlyand are not homologous. Significantly, our resultssuggest that genicula are nonhomologous structuresthat evolved independently in four separate corallinetaxa and from four nongeniculate ancestors belong-ing to distinct evolutionary lineages. On the basis ofour findings Porolithon pachydermum is transferred toHydrolithon as H. pachydermum (Foslie).

32NEW INSIGHTS IN THECRYPTONEMIALES–RHODYMENIALESCOMPLEX AND RESURRECTION OF THEALLIED RED ALGAL ORDER NEMASTOMATALESKYLIN 1925 AS INFERRED FROM rbcLSEQUENCE ANALYSIS AND COMPARATIVEREPRODUCTIVE MORPHOLOGYGavio, B.Department of Biology, University of Louisiana at Lafayette,P.O. Box 42451, Lafayette, LA 70504-2451, USA

In a global molecular phylogeny of florideophyceanred algae inferred from chloroplast-encoded rbcL se-quence analysis, a major monophyletic assemblagecomprises the Cryptonemiales (=Halymeniales), theRhodymeniales, the Schizymeniaceae (Schizymenia, Ti-tanophora, Platoma) and the Nemastomataceae (Nemas-toma, Predaea). The phylogenetic significance of theauxiliary cell and its interaction with the fertilized eggcell in this assemblage is discussed in relation to estab-lished and newly proposed classification schemes. Theorder Nemastomatales Kylin 1925 is reinstated andemended to contain the nonprocarpic Schizymeni-aceae and Nemastomataceae. Unifying characters ofthe Nemastomatales include fertilized carpogonia thatmay establish fusions with carpogonial nutritive cellsprior to the formation of septate connecting filaments,and simple gonimoblasts developing outwardly fromauxiliary cells or from connecting filaments in theirvicinity. The auxiliary cell is a transformed vegeta-tive intercalary cell (Sebdeniaceae), that becomes sur-rounded by either clusters of nutritive cells (Nemas-tomataceae), involucral filaments (Schizymeniaceae)or by three-dimensional ampullary filaments (Haly-meniaceae including the Corynomorphaceae), or ispart of a procarp (Rhodymeniales). The homology ofoutward gonimoblast initiation and maturation intoa simple ball of carposporangia in the Cryptonemi-

ales, Rhodymeniales and Nemastomatales will be il-lustrated.

33GRATELOUPIA TURUTURU (HALYMENIACEAE,RHODOPHYTA): THE CORRECT IDENTITY OFTHE INVASIVE SPECIES IN THE ATLANTICKNOWN AS GRATELOUPIA DORYPHORA ASINFERRED FROM MOLECULAR ANDMORPHOLOGICAL EVIDENCEGavio, B.∗ & Fredericq, S.Department of Biology, University of Louisiana at Lafayette,P.O. Box 42451, Lafayette, LA 70504-2451, USA

Grateloupia doryphora (Montagne) Howe, originally de-scribed from Peru, has repeatedly been reported as aninvasive species in Atlantic and Mediterranean waters.Various attempts to explain this species’ route of in-vasion have, so far, been unsatisfying. In the presentpaper, we provide new evidence on the basis of com-parative rbcL sequence analysis and morphology thatthis invasive species in the NE and NW Atlantic cor-responds to G. turuturu Yamada, originally describedfrom Japan. The true origin of this alga follows a well-recognized trend of invasive marine organisms thathave on various occasions colonized the Atlantic andMediterranean Sea from Pacific NE Asia.

34EFFECTS OF OUTGROUP SELECTION ONPHYLOGENETIC HYPOTHESES OF THEHETEROKONT ALGAEGoertzen, L. R.1,∗ & Theriot, E. C.21Department of Biology, Indiana University, Bloomington,IN 47405; 2Texas Memorial Museum, 2400 Trinity St.,University of Texas, Austin, TX 78705, USA

Nuclear ribosomal SSU and chloroplast rbcL data forheterokont algae and potential outgroups were ana-lyzed separately and together under parsimony. A se-ries of taxon sampling experiments were performed.Traditional heterokont classes (e.g. diatoms, phaeo-phytes, etc.) were monophyletic in most analyses ofeither dataset and in both together. Relationshipsamong classes and of heterokonts to outgroup taxaare sensitive to taxonomic sampling. Stability of het-erokont algae relationships was analyzed by deletion ofoutgroup classes, starting with those presumably mostdistant from the heterokonts to those closest. In onlythree analyses using SSU data were the heterokontsmonophyletic: with all available outgroup taxa, withthe outgroup being hyphochytrids alone or with theoutgroup being hyphochytrids plus Developayella. ForrbcL data, heterokonts were monophyletic when all

ABSTRACTS 13

available rhodophytes were used, when any combi-nation of rhodophytes tested were used, and whenrhodophytes plus bacteria were used. Any addition ofcryptophyte and/or haptophyte sequence resulted ina nonmonophyletic heterokont algae. In both cases,distribution of heterotrophic stramenopiles amongthe heterokont algae changed as different outgroupswere used. Combined data was similarly equivocalabout monophyly of the heterokont algae. The litera-ture suggests that this result is obtained regardless ofwhether parsimony or likelihood methods are used,and that is because taxon sampling affects all inferenceprocedures. We suggest not only that more molecu-lar data be obtained, but that morphological evidencefor monophyly of the heterokonts be re-examined. Fi-nally, a community effort needs to be made to syn-chronize character sampling across different datasetsto increase the number of taxa sampled and to createparallel datasets for all data types.

35SPECIES DIVERSITY OF MICROBIALCOMMUNITIES IN A NORTHERN TEMPERATEHUMIC LAKEGraham, J. M.∗, Kent, A. D., Lauster, G. H.,Yannarell, A. C., Graham, L. E., Kratz, T. K. &Triplett, E. W.Limnology Laboratory, Center for Limnology, University ofWisconsin, 680 N. Park St., Madison, WI 53706-1492,USA

Species richness and species diversity of bacterioplank-ton, phytoplankton and protoplankton were exam-ined in Crystal Bog, a humic lake in northern Wiscon-sin, as part of an NSF sponsored Microbial Observa-tory Program. Crystal Bog is part of the North Temper-ate Lakes Long-Term Ecological Research site. Auto-mated ribosomal intergenic spacer analysis (ARISA)was used to assess bacterial diversity. Phytoplanktonand protoplankton were enumerated in a settlingchamber with an inverted microscope. Four distinctphases in the ice-free season of the bog can be rec-ognized based on microbial populations. The firstphase extends from ice-out until about the first weekof April. During this phase three species of dinoflag-ellates come to dominate the phytoplankton, withGlenodinium quadridens representing 60% of total phy-toplankton biovolume. By mid-April the spring di-noflagellate blooms collapse. The second phase is aperiod of instability as a series of species dominatesthe phytoplankton. In mid-July dinoflagellates againdominate the third phase, and Peridinium limbatumalone represents 90% of the bog phytoplankton. Thefourth phase is a stable period as P. limbatum slowlydeclines in late summer and fall. A strong correlation

was found between bacterial and phytoplankton diver-sity (Shannon–Weaver Index) in this bog, suggestingthe two microbial communities are linked. The proto-plankton, however, were relatively uniform through-out the ice-free period. The ice-covered period maybe treated as a fifth phase. When snow accumulatesover the ice-covered bog, light penetration is blockedand photosynthesis shut off. Heterotrophic protozoaassume dominance in the plankton.

36PHYLOGENY OF THE GRACILARIACEAE(GRACILARIALES, RHODOPHYTA) INFERREDFROM rbcL SEQUENCE ANALYSIS: TAXONOMICIMPLICATIONSGurgel, C. F. D.∗

Department Botanica, CCS, Institute de Biologia,Universidade Federal do Rio de Janeiro, Ilha do Fundao,Rio de Janeiro 21941-900, RJ, Brazil; Department ofBiology, University of Louisiana at Lafayette, P.O. Box42451, Lafayette, LA 70504-2451, USA

This research promotes the correlation of molecu-lar phylogenies and morphological data with bio-geographic hypotheses for the economically impor-tant agarophyte family Gracilariaceae. The genericconcepts are evaluated on the basis of chloroplast-encoded rbcL sequences from 150+ specimens world-wide. The results confirm the monophyly of the fam-ily and identifies three large clades, one of whichcorresponds to the ancestral, antiboreal genera Cur-diea and Melanthalia, one to Gracilariopsis, and oneto Gracilaria sensu lato which identifies at least ninedistinct independent evolutionary lineages, includ-ing Hydropuntia. The species currently attributed toHydropuntia comprise two well-supported clades withdifferent biogeographic patterns, one composed ofIndo-Pacific species and the other of atlantic species.At least the three most basal clades within Gracilariasensu lato deserve to be considered distinct genera:(1) a new genus centered around G. chilensis andG. tenuistipitata; (2) Hydropuntia sensu stricto encom-passing pacific species (G. urvilleii, G. eucheumatoides,G. edulis), and (3) a new genus composed of atlanticspecies currently placed in Hydropuntia (G. cornea,G. crassissima, G. usneoides). Cystocarp features withinthe Gracilaria senso lato clades are more phyloge-netically informative than do male characters. Thehenriquesiana-type of spermatangial concepacle ap-peared independently at least four times. The textorii-type of male apparatus is represented in two distinctclusters of Gracilaria. Several unknown and poorly de-scribed species are being described, resurrected fromsynonymy or re-circumscribed. G. textorii seems to bepart of a major complex of flat species in the Pacific

14 ABSTRACTS

Ocean. The current number of Gracilariaceae is un-derestimated in the Western Atlantic due to conver-gence in habit type and the apparent homoplasy invegetative and reproductive anatomy.

37THREE NEW SPECIES OF GRACILARIOPSIS(GRACILARIALES, RHODOPHYTA) FROM THENORTH-WESTERN ATLANTICGurgel, C. F. D.1,2,∗ & Fredericq, S.21Department Botanica, CCS, Institute de Biologia,Universidade Federal do Rio de Janeiro, Ilha do Fundao,Rio de Janeiro 21941-900, RJ, Brazil; 2Department ofBiology, University of Louisiana at Lafayette, P.O. Box42451, Lafayette, LA 50704-2451, USA

A recent molecular phylogenetic study inferred fromchloroplast-encoded rbcL sequence analyses based on20 specimens of Gracilariopsis. Dawson 1949 worldwideconfirmed the monophyly of the genus and revealedthe existence of three new Caribbean species (Gurgeletal. J. Phycol., submitted). Gracilariopsis sp. 1 collectedin the Mexican Gulf of Mexico is sister to G. tenuifrons.Gracilariopsis sp. 2 collected in Caribbean Panama(Colon City) and Venezuela (Paraguana Penınsula)is morphologically closely related to G. panamensis.Gracilariopsis sp. 3 collected in Venezuela (La Velade Coro) is distinct from all other terete and stringyspecies that characterize the genus by being a flat-foliose taxon; it also shows a basal topology with un-certain phylogenetic relationship to an undeterminedspecies from Japan and China and to G. heterocladafrom the Philippines. The lack of clear-cut vegetativeand reproductive features among the species coupledwith a high degree of thallus plasticity may accountfor the fact that genetically distinct species were notpreviously recognized as taxonomically distinct. Ourmolecular and morphological studies reveal that thediversity of Gracilariopsis species in the western Atlanticand probably in the rest of the world is currently un-derestimated. Morphologically detailed descriptionsfor all three new species are provided.

38THE PLASTID OF DINOPHYSIS(DINOPHYCEAE): PHYLOGENETIC EVIDENCEFOR A PERMANENT REPLACEMENTHackett, J. D.1,∗, Maranda, L.2 & Bhattacharya, D.11Department of Biological Sciences, Center for ComparativeGenomics, University of Iowa, Iowa City, IA 52242;2Graduate School of Oceanography, University of RhodeIsland, Narragansett, RI 02882-1197, USA

In the photosynthetic dinoflagellate Dinophysis, pig-ment composition and ultrastructural charactersplace the origin of the chloroplast with the crypto-phytes. Presented here is the first molecular data fromthe plastid of Dinophysis. We cloned and sequencedthe coding regions of psbA and small subunit (SSU)rDNA from four populations of D. acuminata and fromD. acuta. These data were used to test two hypothesesabout Dinophysis plastid evolution: (1) The plastid isof cryptophyte origin; and (2) The plastid is a perma-nent replacement. The psbA-coding region was iden-tical among the populations of D. acuminata and be-tween this species and D. acuta. On the other hand,the SSU rDNA showed polymorphisms, both betweenspecies and among populations. Phylogenetic analysisshows that both psbA and SSU rDNA sequences firmlyplace the Dinophysis spp. plastid within the crypto-phytes, confirming its origin through plastid replace-ment. The polymorphic SSU rDNA sequences grouptogether and are sister to a cryptophyte ultraplankter(OCS20). The SSU rDNA sequence heterogeneity be-tween species (about 1%) is comparable to the hetero-geneity among different isolates of D. acuminata, sug-gesting these are population-level differences and notindicative of different plastid captures by Dinophysis.Interestingly, a second class of cloned coding regionswas also isolated from each population. These psbAand SSU rDNA sequences were evolutionarily moredivergent and specifically related to florideophyte redalgae. Given the mixotrophic habit of Dinophysis, thepossibility arises that this second class may have comefrom red algal preys in the food vacuoles of our single-cell isolates. These results highlight the importance ofsampling multiple genes and populations in determin-ing the complex evolutionary history of the Dinophysisplastid.

39BIOASSESSMENT OF STREAM-WATER QUALITYUSING BENTHIC AND PLANKTONIC ALGAECOLLECTED ALONG AN URBAN INTENSITYGRADIENT IN THE EASTERN CORNBELTPLAINS ECOREGION, OHIO, USAHambrook, J. A.US Geological Society, 6480 Doubletree Ave., Columbus,OH 43229-1111, USA

Algae possess many attributes that make them idealorganisms to employ in water-quality investigations.They are ubiquitous, ecologically important, and sen-sitive to a broad range of stressors; moreover, they re-spond rapidly to changes in water quality. As part of theUSGS National Water Quality Assessment (NAWQA)

ABSTRACTS 15

Program, two methods of analyzing stream-dwellingalgae were used to assess relations among nutrientconcentrations, algae, and overall biological integrityof streams along a gradient from agricultural to ur-ban land cover. One method is based on algal pro-duction (chlorophyll a, biomass, and 48-h measuresof dissolved oxygen), whereas the other is based onalgal community assemblages (species abundance,biovolume, and autecology). Quantitative periphytonand phytoplankton samples were collected from 30stream reaches in small watersheds (drainage area 7.7–188.7 km2) in south-west Ohio, during July 2000. Phy-toplankton Chl a ranged from 0.5 mg/L in an urbanarea to 43 mg/L in an agricultural basin, whereas theepilithic periphyton Chl a ranged from 2 mg/m2 inan urban area to 142 mg/m2 in an agricultural basin.Spearman correlations were used to indicate relationsbetween the physical, chemical, and biological factorsand measures of algal production. Multivariate analy-sis of algal species abundance and metrics will be usedto characterize gradients of algal community responserelative to chemical and landscape factors. Results willbe discussed in relation to the influence of urban land-use intensity and the US Environmental ProtectionAgency nutrient criteria proposed for this region. Theextent to which the algal production and communitystructure results are useful for bioassessment of streamhealth will be evaluated with regard to understand-ing community responses to organic enrichment, dis-solved oxygen, specific conductance, light availability,pesticide concentrations, and the monitoring of wa-tershed management practices.

40A NEW METHOD FOR STUDYING NUTRIENTLIMITATION OF PERIPHYTON : A CASE STUDYFROM ACID MINE DRAINAGE STREAMSHamsher, S. E.1,∗, Casamatta, D. A.1, Filkin, N. R.1,McClintic, A. S.1, Chiasson, W. B.1, Verb, G. R.2 &Vis, M. L.11Department of Environmental and Plant Biology, OhioUniversity, Athens; 2Department of Biology, Ohio NorthernUniversity, OH, USA

Acid mine drainage (AMD) affects about 16 900 km ofstreams in the Appalachian region, but little is knownabout the biology of these habitats. Typically, thesehabitats have low primary productivity most likely dueto metal stress. However, these streams are also very lowin nutrients. Traditionally, nutrient limitation studiesof periphyton have been conducted employing ter-racotta pots. Recently, research has concluded thatthis methodology may have inherent flaws due to vari-able porosity. Therefore, development of new nutri-

ent diffusing substrates is needed. To test a new ap-proach for nutrient diffusion, Petri dishes were filledwith agar and the nutrient of choice. A Whatmanglass microfiber filter (GF/F) was attached to the topof the dish, which served as the medium throughwhich the nutrients diffused and as a uniform surfacearea for periphyton colonization. Before testing in astream impacted by acid mine drainage, laboratorystudies were conducted to simulate field conditions.The Petri dishes readily diffused the nutrients andwere durable to the acid conditions. Six replicates witha control, nitrogen (0.5 M), phosphorus (0.5 M), andnitrogen + phosphorus (0.5 M of each) Petri disheswere deployed in four AMD impacted streams for themonth of February. Samples were analyzed for chloro-phyll a, ash-free dry mass (AFDM), and taxa present.The chlorophyll a analyses showed the phosphorustreatment to be significantly (P < 0.05) greater thanall other treatments and the nitrogen treatment wassignificantly (P < 0.05) lower. However, these trendswere not seen in the AFDM results with no differenceamong treatments detected. Seasonal assessment ofthis approach is currently under way.

41IMPACTS OF REDUCED SALINITY ONSEAGRASSES IN INDIAN RIVER LAGOONHanisak, M. D.Harbor Branch Oceanographic Institution, Fort Pierce, FL34946, USA

From November 1993 to November 1995, a study wasconducted in Indian River Lagoon (IRL) to deter-mine relationships of light attenuation, water qual-ity, and seagrass at sites representing a range of waterquality conditions. There were considerable interan-nual differences at the sites. The most striking eventoccurred at a station in northern Banana River, anarea of IRL considered the least anthropogenicallyimpacted. This station had a well-developed, multi-species seagrass bed (Halodule wrightii and Syringodiumfiliforme, with small quantities of Halophila engleman-nii). Throughout the first year, salinity was stable (90%of weekly values ranged from 26 to 32 ppt). Begin-ning in November 1994, the cover, shoot density, andbiomass of all three species declined precipitously dueto sharply reduced salinities associated with high rain-fall and run-off. Salinities during the following yearvaried little and remained low (90% of weekly valuesranged from 13.5 to 19.8 ppt). The lack of recoveryto earlier salinity levels was due to the long residencetime (about 1 year) in that portion of IRL. Seagrasscover, shoot density, and biomass reached minima inMay 1995. By August 1995, Halodule began to recover,

16 ABSTRACTS

but nearly 8 years later, Syringodium has not recoveredto 1994 levels.

4218S-BASED TAXONOMY AND INTRASPECIFICITS SEQUENCE VARIATION IN THE MARINEFUNGAL ENDOSYMBIONT HALOGUIGNARDIAIRRITANS INFECTING CYSTOSEIRA OSMUNDACEAALONG THE CALIFORNIAN COASTHarvey, J. B. J.Department of Ecology and Evolutionary Biology, A316Earth and Marine Sciences, University of California, SantaCruz, CA 95064, USA

Abstract withdrawn

43INTRASPECIFIC GENETIC VARIATION INH. IRRITANS, A FUNGAL ENDOSYMBIONT OFMARINE BROWN ALGAE ON THE NORTHAMERICAN PACIFIC COASTHarvey, J. B. J.Department of Ecology and Evolutionary Biology, A316Earth and Marine Sciences, University of California, SantaCruz, CA 95064, USA

The marine ascomycete genus Haloguignardia occursendophytically in members of the marine brown al-gal family Sargassaceae globally. This example of en-dosymbiosis has been morphologically described: thefungal component internally infects the algal host re-sulting in prolific cell growth, forming galls composedchiefly of host algal cells but containing fungal repro-ductive structures and vegetative hyphae. H. irritansinduces the formation of galls in the brown algaeCystoseira osmundacea and Halidrys dioica along the Pa-cific coast from Oregon to Baja California, Mexico.Using culture-independent molecular techniques, Isequenced the 18S rDNA gene region for H. irritansand generated a 18S-based taxonomy consistent withthe current taxonomy for this morphological species.In order to study intraspecific genetic variation inH. irritans, I have sequenced the ITS rDNA (ITS 1, 2and the 5.8 s) regions for five separate gall-tissue sam-ples from Santa Rosa Island in southern Californiaand for five samples from Monterey and Carmel incentral California. Intraspecific DNA sequence varia-tion in the ITS regions of H. irritans reveals consistentsequence divergence between sites sampled. The fun-gal ITS regions for H. irritans total 613 bp in lengthand contain 40 synapomorphic characters for a totalof 6.5% variation in informative loci between southernand central Californian sites. This value is similar to

those found for the ITS and other gene regions previ-ously used by researchers investigating species bound-aries at the intraspecific level in symbiotic, terrestrialfungi. In addition to ITS 1, 2 and the 5.8 s gene re-gions, I am currently using the 5’ end of the EF1acoding region to construct intraspecific genealogiesfor H. irritans. By comparing these genealogies to eachother and to the geographic distribution of samples, Iaim to determine if more than one genetic species ispresent within the morphological species H. irritans.

44SYNCHROTRON-BASED INFRARED IMAGINGOF EUGLENA GRACILIS SINGLE CELLSHirschmugl, C.1,∗, Bunta, M.1, Holt, J.1, Giordano,M.2, Skilirov, A.3 & Strickler, J. R.41Department of Physics, University ofWisconsin-Milwaukee, Milwaukee, WI 53211, USA;2Faculty of Sciences, Institute of Marine Sciences, Universityof Ancona, Via Brecce Bianche, 60131 Ancona, Italy;3Advanced Analysis Facility; 4WATER Institute, Universityof Wisconsin-Milwaukee, Milwaukee, WI 53211, USA

Infrared (IR) microspectroscopy is used to examineand identify the chemistry in individual living cells ofEuglena gracilis. The spectra provide relative concen-trations of lipids, proteins and carbohydrates in thespecimen. Diffraction-limited, spatially resolved IR im-ages of single cells of the microalga were measured us-ing synchrotron radiation as a bright IR source. Thesecontour maps reveal the distributions of the proteins,lipids and carbohydrates including the phospholipids,sugars and paramylon. We compare the images withthe biochemistry for E. gracilis. We also present theIR images for two different cells, which were exposedto different culture conditions prior to the measure-ments. The overall trends observed for the two speci-mens are in qualitative agreement with the hypothesisthat there was a significantly reduced concentrationof nitrogen in the culture as a function of time. Im-portantly, this study demonstrates the potential to ex-amine changes in the chemistry of living cells whilemodifying environmental stimuli.

45CELL SIGNALING IN THECHEMOACCUMULATION RESPONSE OF THECOLONIAL GREEN ALGAASTREPHOMENE GUBERNACULIFERAHoops, H. J.∗ & Gifford, S. M.Biology Department, SUNY-Geneseo, 1 College Circle,Geneseo, NY 14454, USA

ABSTRACTS 17

A. gubernaculifera can grow on acetate even in the dark.Interestingly, it displays a well-developed chemoaccu-mulation response to added acetate. We suggest thatthis chemoaccumulation results from a receptor-basedsignaling pathway because the alga responds to thestructurally similar molecule propionate even thoughthe latter compound cannot support growth. Basedon suggestions about chemotactic signaling pathwaysin other eukaryotes and postulated phototactic re-sponse of some algae, we hypothesized that the signal-ing pathway involves heterotrimeric G-proteins. Theeffectiveness of the chemoresponse was determinedby measuring the diameter of the chemoaccumula-tion cloud after addition of 10 mL aliquots of me-dia containing acetate to colonies swimming in me-dia without acetate. Neomycin, which inhibits the G-protein dependent activity of phospholipase C, com-pletely inhibited chemoaccumulation at 100 mM, andmarkedly reduced the density of the accumulationresponse at 10 mM with no obvious changes in gen-eral colonial motility. EGTA, a calcium chelator, abol-ished the chemoresponse. Mastoporan, a G-proteinactivator, caused accumulation even in the absenceof acetate. These results support the hypothesis thatchemoaccumulation in A. gubernaculifera uses a G-protein mediated, calcium-dependent, cell-signalingpathway.

46MAA SYNTHESIS AND ACCUMULATION INPOLAR MACROALGAE ARE CONTROLLED BYABIOTIC FACTORSHoyer, K.1,∗, Karsten, U.2 & Wiencke, C.11Alfred Wegener Institute for Polar and Marine Research,Am Handelshafen 12, D-27570 Bremerhaven; 2Institute ofAquatic Ecology, University of Rostock,Albert-Einstein-Strasse 3, D-18075 Rostock, Germany

Mycosporine-like amino acids (MAAs) are regardedas powerful sunscreens protecting the algae againstharmful UV radiation. The MAA protection efficiencywas tested in algal samples by measuring the opti-mum quantum yield of photosynthesis using pho-tosystem II fluorescence. It could be demonstratedthat the recovery of photosynthesis after exposure toenhanced UV radiation is faster in individuals withhigh MAA content. MAAs can be synthesized in sev-eral polar macroalgae in response to different radia-tion conditions. Although MAA induction patterns arevery species-specific, some similarities can be found.Field studies indicate that plants from different growthhabitats providing distinct radiation climate can begrouped into three physiological categories depend-

ing on their MAA content. The first group (I) includesmainly deep-water species, typically lacking MAAs. Thesecond group (II), algal species found in a broad rangeof water depths (eu- and sublittoral), which are ableto flexibly synthesize and accumulate MAAs. The thirdgroup (III) includes supra- and eulittoral taxa, whichalways contain high MAA concentrations. In labora-tory studies, we showed that taxa of group II and IIIresponded in three different ways based on MAA accu-mulation when exposed to different radiation condi-tions (PAR, PAR + UVA, PAR + UVA + UVB). Eitherthey: (a) exhibit highest total MAA concentration un-der the full artificial spectrum; (b) increase their MAAconcentration after exposure to PAR and PAR + UVAor (c) MAA concentration declines after exposure tothe full spectrum. Our studies have indicated thatwhen coupled with UVR, exposure to temperaturefluctuations ranging from 0 to 10 ◦C also affect MAAbiosynthesis.

47AN EXAMINATION OF THE EFFECTS OF ARESERVOIR, LAKE ASHTABULA, ON THEPERIPHYTIC ALGAE IN THE SHEYENNE RIVER,NORTH DAKOTAJaskowiak, M. A.∗, Fawley, K. P. & Fawley, M. W.Department of Biological Sciences, North Dakota StateUniversity, Fargo, ND 58105, USA

The Sheyenne River is a third order stream that drainsa significant portion of central and eastern NorthDakota. In 1950, the Baldhill Dam was built and as aresult, the reservoir, Lake Ashtabula, was formed. Theperiphytic algae in this river were extensively studiedfrom 1997 to 1999. During this research, the effectsof differences in environmental variables on the algalcommunities were assessed with Canonical Correspon-dence Analysis (CCA). In this analysis, the periphyticalgal communities in the downstream sites appearedto be quite different from those communities foundupriver of Lake Ashtabula. Other research on differ-ent rivers has shown profound changes in the algalcommunity after a dam was built along the river. Re-dundancy Analysis (RDA) was used to determine ifthe sites downstream are more statistically similar withLake Ashtabula than with the upstream sites. Finally,CCA was used to examine which environmental vari-ables explain the most variance in Lake Ashtabula andthe downstream sites.

18 ABSTRACTS

48RELATIONSHIP BETWEEN PERIODICRESUSPENSION EVENTS AND PLANKTONICDIATOM COMMUNITY STRUCTURE IN LAKEMICHIGAN: A FIELD AND LABORATORYINVESTIGATIONJulius, M. L.Department of Biological Sciences, St. Cloud StateUniversity, St. Cloud, MN, USA

Lake Michigan provides an ideal location for com-paring episodic physical forcing events (storms) onphytoplankton processes and the more persistent sea-sonal variability of phytoplankton communities. Thisis due to the duration and extent of the highly tur-bid, recurrent coastal plume (RCP) in the lake dur-ing the winter/early spring. Although the RCP cancoincide with the initiation of the basin wide springdiatom bloom, linkages between the duration and in-tensity of the plume and the prominent role of lightavailability in regulating Lake Michigan phytoplank-ton growth during the spring isothermal period havebeen postulated, but not verified. The concurrentphysical and biological events provide a novel oppor-tunity to examine phenomena associated with the RCPaffecting the distribution and abundance of species inLake Michigan’s planktonic diatom flora. In this study,planktonic diatom assemblages from pre, post and ac-tive spring plume events were examined from stationsalong Lake Michigan’s southern shoreline. Speciesabundance changed rapidly during storm events. Sed-iment resuspension via storm activity created a sub-optimal growth environment. Post-storm event di-atom phytoplankton communities were floristicallydistinct from prestorm event communities, with rest-ing cell-forming taxa playing a significant role in thesecommunity-restructuring periods. Laboratory simu-lations of resuspension events using Lake Michigansediments were conducted under a variety of en-vironmental conditions. Parameters varied includedday length, temperature, and silica. The resultingassemblages were quantitatively counted. A statisti-cally significant relationship was identified betweenday length and the vegetative growth of many rest-ing cell-forming diatom species. When day lengthwas calculated for poststorm event field data, it re-vealed a high correlation between poststorm eventcommunities and those predicted by the labora-tory simulations. Timing of storm events and lat-itudinal position of the aquatic system are thenimportant elements for consideration when pre-dicting diatom phytoplankton community structuredue to the relationship these factors have with daylength.

49ESTIMATING DIVERGENCE TIMES WITHIN THECHAROPHYTA: A BAYESIAN APPROACH USINGFOSSIL AND DNA SEQUENCE DATAKarol, K. G.1,∗, McCourt, R. M.2 & Delwiche, C. F.11Department of Cell Biology and Molecular Genetics,University of Maryland – College Park, College Park, MD20742; 2Department of Botany, Academy of NaturalSciences, 1900 Benjamin Franklin Parkway, Philadelphia,PA 19103, USA

Morphological and molecular studies have advancedour understanding of charophycean green algal re-lationships. A recent multigene phylogenetic analysishas identified the Charales as the closest living rela-tives of land plants with the Coleochaetales sister tothe Charales/land plant lineage. With a robust phy-logeny now in hand, it is possible to explore phylogeny-dependent questions that were previously difficult toassess. Estimating the divergence time of the landplant lineage is one such question. The most recenttime estimate for the colonization of land by plantsis 1061 ± 109 million years ago and 703 ± 45 millionyears ago for the divergence of vascular plants andbryophytes, a result much older than that found inthe fossil record (roughly 470 million years ago). Sev-eral problems are inherent in estimating divergencetimes using DNA sequence data; these include the as-sumption of a molecular clock and choosing from asparse fossil record for an external calibration date.Unlike most algae, a rich fossil record exists for theCharales in the form of calcified oospores termed gy-rogonites. Representative gyrogonites that can be at-tributed to all six of the extant genera in the Characeaehave been identified with reasonable accuracy. Thesesix calibration points, identified from a closely relatedlineage of land plants, can be used in conjunction witha multigene DNA dataset to estimate the time that theland plant and Charales lineages diverged from theircommon ancestor.

50PUBLIC OUTREACH MATERIALS REGARDINGHARMFUL ALGAL BLOOMS AND THEIRPOSSIBLE EFFECTS ON HUMAN HEALTHKirkpatrick, B.1,∗, Fleming, L. E.2, Stephan, W. B.2,Backer, L.3, Clark, R.4, Squicciarini, D.2, Weisman,R.2 & Van De Bogart, G.21Mote Marine Laboratory, 1600 Ken Thompson Parkway,Sarasota, FL 34236; 2NIEHS Center, University of Miami,4600 Rickenbacker Causeway, Miami, FL 33149; 3Centerfor Disease Control, 1600 Clifton Road NE, Atlanta, GA30333; 4Florida Department of Health, 4052 Bald CypressWay, Tallahassee, FL 32399, USA

ABSTRACTS 19

The potential interactions between marine and fresh-water harmful algal blooms (HABs) and humans areincreasing. Humans are exposed through food, drink-ing water, and recreational and occupational water useto an increasing number of organisms and their tox-ins. Nevertheless, the amount of clinical and epidemi-ologic research concerning acute and chronic humanhealth effects from the HAB organisms and their tox-ins is relatively sparse. At the same time, the publicis increasingly aware of and interested in the poten-tial dangers associated with exposure to HABs. Publichealth authorities and researchers must respond tothese public health concerns. The development of ap-propriate educational and outreach materials basedon limited scientific databases is the challenge of in-forming the public concerning the possible humanhealth effects of HAB organisms and their toxins, andtheir prevention. Educational materials developed bya group of researchers and public health personnelfor general HABs, Florida Red Tide Toxins (brevetox-ins), Cyanobacteria, and Ciguatera are discussed, aswell as methods for their dissemination.

51ENDEMISM AND INVASION IN THE GREATLAKES DIATOM COMMUNITYKreuger, N.∗ & Julius, M. L.Department of Biological Sciences, St. Cloud StateUniversity, St. Cloud, MN, USA

Population dynamics and health for individual GreatLakes diatom species is explored. Information dealingwith how these taxa compete with introduced speciesand rapid environmental changes in modern timesis examined. Diatomists have identified a number ofthese taxa, but discussion is limited with little or noinformation covering the ecological range of the taxaover time. Some of these include Cyclotella americanaFricke; C. bodanica var. stellata Skvortzow; and Stephan-odiscus superiorensis Theriot. A number of taxa endemicto the Great Lakes undescribed in the literature alsoexist. These are species wedged into taxonomic cat-egories from the European taxonomic system. Re-cent advances in the understanding of diatom speciesboundaries, suggest these names are inappropriatelyused for a number of taxa identified in paleolimno-logical investigations of the Great Lakes. This prob-lem developed because taxonomic information out-side of the European flora is not readily available toresearchers, and because the focus of paleolimnolog-ical studies is primarily environmental reconstructionminimizing the time that can be spent unraveling tax-onomically troublesome species. Examples of these

are Cyclotella bodanica var. glabriscula and C. bodanicavar. oligactis. Great Lakes populations of these taxa aresignificantly different from the original populationsdescribed from alpine lakes in Austria and Switzer-land and merit taxonomic separation. Many of theendemic taxa are no longer present in the modernGreat Lakes assemblages. The precise time of theirdisappearance from the system is not know, but modi-fications in Great Lakes diatom populations clearly co-incided with the development of substantial Europeansettlement of the Great Lakes region. C. americana, forexample, was always limited to Lakes Erie and On-tario but disappeared from both of these lakes priorto 1900. With the disappearance of these taxa, came anumber of introductions to the lakes. This work rep-resents the first attempt to document these floristicchanges.

52SYSTEMATICS OF COCCOID GREEN ALGAE:MORPHOLOGY VS. 18S rRNA GENEPHYLOGENYKrienitz, L.1,∗, Wolf, M.1, Hegewald, E.2 &Hepperle, D.1,31Leibniz-Institute of Freshwater Ecology and InlandFisheries, D-16775 Stechlin-Neuglobsow; 2Institute ofChemistry and Dynamics of the Geosphere, Research CentreJuelich, D-52425 Juelich; 3Albrecht-von-Haller Institute ofPlant Sciences, University of Goettingen, D-37037Goettingen, Germany

Classical approaches using morphological charactersfor the circumscription of taxa in coccoid green algaedo not adequately reflect the phylogenetic relation-ships. Phylogenetic trees based on 18S rRNA gene se-quence analysis provide new insights into the system-atics of these algae. We give a review and discuss thecontent of orders of coccoid green algae and evalu-ate the usefulness of some traditionally used diacriticfeatures. Whereas the content of the orders Chloro-coccales and Chlorellales needs to be reduced, the or-der Sphaeropleales comprises more families than inthe traditional circumscription. According to molecu-lar biological investigations the Neochloridaceae, Se-lenastraceae and Scenedesmaceae formerly classifiedin the Chlorococcales and later into the Chlorellalesbelong to the Sphaeropleales. The Hydrodictyaceae,formerly a member of the Protosiphonales, are alsoto be grouped in the Sphaeropleales. Some membersof the Ulotrichales, which propagate by binary fission(e.g. Nannochloris and Catena) cluster together with au-tosporine coccoid taxa within the Trebouxiophyceae.With the example of members of the Selenastraceae,

20 ABSTRACTS

Oocystaceae and Chlorellacea it is shown that the mor-phology of cells as well as the formation of coenobia,spines, mucilage and incrustations cannot be used toseparate genera.

53UV-ACCLIMATION OF CULTUREDPHYTOPLANKTON EXPOSED TO NATURALAND ENHANCED UVB RADIATION ANDMETHODOLOGICAL ASPECTS OF MAAQUANTIFICATIONLaurion, I.∗ & Roy, S.Institut des Sciences de la Mer, Universite du Quebec aRimouski, 310 Allee des Ursulines, Rimouski, Que.,Canada

Bloom-forming dinoflagellates often synthesize highconcentrations of mycosporine-like amino acids(MAAs) as a protection from high PAR and UV radia-tion, which may afford them a competitive advantageover other species. Photoprotection and long-termacclimation to natural and enhanced UVB radiationwere examined during 4 weeks in three dinoflagellatesand one diatom. Semi-continuous, nutrient-repletecultures were maintained outdoors under naturallight, with or without additional UVB (from lamps).The photosynthetic performance (XE-PAM fluorome-try) and the concentration and composition of MAAsand photoprotective carotenoids (PPCs; comprisingxanthophylls) were followed weekly. A great varietyof MAAs was found in the dinoflagellates (up to 10,identified by cochromatography and LC–MS). Largedifferences between sp. (and between two strains ofthe same sp.) were observed. In most cases, the com-position and concentration of MAAs and PPCs in-creased under enhanced UVB. Growth rate and pho-tosynthetic performance were sometime lower underenhanced UVB, while in other cases photoacclimationseemed to occur. The least affected sp. was Alexan-drium tamarense who responded most rapidly to en-hanced UVB. The algae also responded to changesin natural incident radiation. Some methodologicalaspects of MAA quantification were also investigated(with four species of dinoflagellates). Our results in-dicate how freezing (liquid-N) likely breaks the cells,mobilizing the water-soluble MAAs in the filter moist(otherwise highly packaged in fresh cells), while theorganelles containing the pigments remain relativelyintact. The implications of standard sample handlingon the evaluation of MAA concentration in algae andon the estimation of the absorption of suspended ma-

terial in water from in vivo spectroscopy (filter padtechnique) will also be discussed.

54PRESERVATION OF NOSTOCACEANHORMOGONE MOTILITY IN DESICCATEDCALCIUM CARBONATE AGAR PATCHESLazaroff, N.Foundation for Microbiological Analysis, Vestal, NY13850, USA

Filamentous nitrogen fixing cyanobacteria are resis-tant to desiccation, nutrient depletion, adverse tem-perature and challenging photic environments. Thisis generally thought to account for their role as pio-neering forms of life on denuded strata. It has also lentcredence to the possibility that cyanobacteria with pro-longed viability may have been able to survive condi-tions of interplanetary space to implement a pansper-mian hypothesis for the origin of life on earth. Pro-longed retention of viability had been noted in ourcollection of myxotrophically grown strains of nosto-caceans cultured in liquid or solid media containingcalcium carbonate. Such media permitted satisfactoryrecovery and regrowth after storage at low light in-tensities for 2 years or more. Moreover, even the old-est calcium carbonate cultures contained motile hor-mogonia when observed microscopically. This phe-nomenon can be used to advantage in sending cul-tures to other laboratories. Not only are organismsmaintained during passage through the postal systembut since the cultures formed hormogonia readily,it was possible to produce preservable homogeneousagar lawns that generated hormogonia as needed fordemonstration or experiment. A practical techniqueconsists of seeding axenic strains of Nostoc speciesgrown in liquid shake culture under cool-white fluo-rescent illumination into solid media containing 0.7%sucrose, 0.05% finely divided calcium carbonate and1.4% purified agar. The preparations are incubatedunder red fluorescent illumination to produce severalcrops of hormogonia in successive cycles of develop-ment, within the agar. The heavily grown lawns are cutinto disks or squares, then transferred to dishes anddried in desiccators with anhydrous calcium sulfate.The dry patches produce swarms of hormogonia in 2or 3 h, depending upon the rate of rehydration. Thepatches are facile tools for purifying cultures throughthe isolation of hormogonia and studying cyanobac-terial physiology by the rapid response of motile hor-mogonia.

ABSTRACTS 21

55FATTY ACID AND STEROL COMPOSITION OF AKARENIA BREVIS BLOOM IN THE GULF OFMEXICOLeblond, J. D.1,∗ & Chapman, P. J.21Department of Biology, P.O. Box 60, Middle TennesseeState University, Murfreesboro, TN 37132; 2USEnvironmental Protection Agency, Gulf Ecology Division,National Health Effects and Environment ResearchLaboratory, 1 Sabine Island Dr, Gulf Breeze, FL 32561,USA

In the Gulf of Mexico, recurring algal bloomscaused by Karenia brevis (formerly known as Gymno-dinium breve) have significant adverse health and eco-nomic impacts. K. brevis is one member of a smallgroup of dinoflagellates, related morphologically andby DNA-based phylogenetic analysis, that synthesizethe carotenoid, gyroxanthin diester, in place of themore widely distributed peridinin. While this novelphotopigment has been proposed as a biomarker, es-pecially for remote-sensing imaging technologies, todetect the emergence of K. brevis blooms, other chem-icals such as sterols and triglycerides, respectively, withpotential to report the distribution and physiologicalcondition of K. brevis are required. Recent work fromour laboratories characterizing the lipids of dinoflag-ellates has confirmed that K. brevis, together with thosefew close relatives lacking peridinin, possesses a rela-tively simple sterol profile comprised of two unusualprimary 4-methyl sterols, designated ED and NED,each with an ergosterol-type side chain. A recent di-noflagellate bloom in the waters of the north-west Gulfof Mexico near the Gulf Breeze EPA laboratory pro-vided an opportunity to examine the usefulness ofthese sterols and other lipids as indicators of K. brevisin phytoplankton communities. Lipid extracts of fil-tered bloom samples, fractionated to separate freeand esterified sterols, were examined by GC–MS oftrimethylsilyl ether derivatives. ED and NED were themajor sterols found in all bloom samples. Fatty acidsfound in lipid fractions containing membrane phos-pholipids, chloroplast-associated glycolipids, and stor-age triglycerides, respectively, differed significantly.The glycolipid fraction was found to contain octade-capentaenoic acid [18 : 5(n-3)], a fatty acid commonlyassociated with dinoflagellates. The phospholipid frac-tion was found to contain small amounts of the re-cently described highly unsaturated fatty acids, oc-tacosaoctaenoic acid [28 : 8(n-3)] and octacosahep-taenoic acid [28 : 7(n-6)]. Fatty acids from the triglyc-eride fraction were more abundant than those associ-ated with glycolipids or phospholipids.

56LIPID BIOMARKER ANALYSIS OF THE TOXICDINOFLAGELLATE PFIESTERIA PISCICIDA:DISTRIBUTION OF STEROLS AND FATTY ACIDSWITHIN THE CLASS DINOPHYCEAELeblond, J. D.1,∗ & Chapman, P. J.21Department of Biology, P.O. Box 60, Middle TennesseeState University, Murfreesboro, TN 37132; 2USEnvironmental Protection Agency, Gulf Ecology Division,National Health Effects and Environment ResearchLaboratory, 1 Sabine Island Dr, Gulf Breeze, FL 32561,USA

Within US waters, regular blooms of harmful dinoflag-ellates occur in the Gulf of Mexico and ChesapeakeBay regions. Although the causes of blooms are notfully understood, events in Gulf of Mexico waters havebeen recorded for over 30 years, and are almost ex-clusively caused by the photosynthetic dinoflagellate,Karenia brevis. Conversely, blooms in the ChesapeakeBay region, caused by the heterotrophic dinoflagellatePfiesteria piscicida, appear to be a relatively new phe-nomenon, and are hypothesized to be linked to anincrease in nutrient-rich runoff from chemical plantsand livestock farms along tributaries leading into theChesapeake. Despite the environmental, economic,and human health relevance of P. piscicida, there ap-pears to be no published work on the characterizationof its lipid composition. The objective of this studywas, therefore to examine the sterol and fatty acidcomposition of cultured P. piscicida isolates as a pre-cursor to eventual field studies of blooms of this or-ganism. GC–MS analysis of trimethylsilyl ether deriva-tives of sterols in free sterol and sterol ester fractionsrevealed that the overwhelming majority of sterolswas found as free sterols. Furthermore, free sterolswere found to resemble those of other dinoflagel-lates, with the dominant compound being the com-mon dinoflagellate sterol, dinosterol; a number ofother 4-methyl sterols common to other dinoflagel-lates were also identified. The fatty acids of P. piscicidawere found to be primarily associated with a fractioncontaining cellular membrane phospholipids; smallamounts of the recently described highly unsaturatedfatty acids, octacosaoctaenoic acid [28 : 8(n-3)] and oc-tacosaheptaenoic acid [28 : 7(n-6)], were observed inthis fraction. The dominant fatty acid (approximately40–60% of the phospholipid fatty acids) was docosa-hexaenoic acid [22 : 6(n-3)]. Unlike K. brevis (see ac-companying poster), P. piscicida does not appear topossess significant amounts of unusual sterols or fattyacids which may serve as potential biomarkers for thisorganism.

22 ABSTRACTS

57THE TRANSITION FROM ALGAE TOEMBRYOPHYTES: CHLOROPLASTPHYLOGENOMIC EVIDENCE (II)Lee, J.∗ & Manhart, J. R.Department of Biology, Texas A&M University, CollegeStation, TX 77843-3258, USA

The transition of plant life from aquatic algae to landplants was one of the major events in the history oflife. However, in hypothesizing the evolutionary pathof the transition, limited shared phenotypic charac-ters in aquatic algae and land plants (embryophytes)have been a major hinderance. Chloroplast genomescontain characters useful in tracing evolutionary his-tories. Embryophyte chloroplast genomes are distin-guished from algal cpDNAs by the presence of over20 group II introns and three ribosomal protein oper-ons (rpl23, clpP and 3Œrps12 operons). These phy-logenomic features indicate a phylogenetic relation-ship of charophytes and embryophytes. In additionto these operons and introns, the evolution of rRNAand psbB operon evolution of streptophyte lineageswill be incorporated with major biological phenotypicfeatures to produce a phylogenetic tree. Basal em-bryophytes, the antithetic hypothesis, monophyly ofembryophytes, and paraphyly of charophytes will bediscussed. Strepotophytes are classified into three ma-jor groups (basal streptophytes, mid-divergent strepto-phytes and late divergent charophytes-embryophytes).

58ACTIN PHYLOGENY IN THE CHAROPHYTALewandowski, J. D.∗ & Delwiche, C. F.Department of Cell Biology and Molecular Genetics,University of Maryland – College Park, College Park, MD20742, USA

Photosynthetic green plants, the Viridiplantae, arecomposed of two distinct lineages, the Chloro-phyta and Charophyta. The Chlorophyta includethe Chlorophyceae, Trebouxiophyceae, Ulvophyceaeand most prasinophytes. The Charophyta includethe Mesostigmatales, the traditional charophyceangreen algal orders Chlorokybales, Klebsormidiales,Zygnematales, Coleochaetales and Charales, and landplants, referred to here as Embryophyceae. The Em-bryophyceae are embedded within the paraphyleticcharophycean green algae, so land plants are, there-fore best considered a specialized group of green al-gae adapted to terrestrial life. Due to the close evo-lutionary relationship between green algae and Em-

bryophyceae, characterizing the early evolution anddiversification of land plants depends on understand-ing phylogenetic relationships among the less exten-sively studied green algal members of the Charophyta.Relationships within the Charophyta have previouslybeen based on morphology and inferred through phy-logenetic analyses of molecular data that include ri-bosomal DNA and several genes from the chloroplastand mitochondrial genomes. To this point, however,few phylogenetic analyses of nuclear, protein-codinggenes have been conducted. We are attempting to iso-late and sequence actin-coding regions from represen-tative members of the Charophyta. Actin is a highlyconserved protein that is ubiquitous among eukary-otes; these features make actin an ideal subject forcomparative sequence analysis. A major componentof the cytoskeleton, actin plays a number of impor-tant roles in plant cell processes such as cell divisionand cytoplasmic streaming. Hence, in addition to be-ing potentially useful for resolving organismal rela-tionships, the evolution of the actin protein itself isintrinsic to the study of morphological evolution anddevelopment within green plants.

59NUMEROUS TRANSITIONS TO LAND IN GREENPLANTS: THE ‘OTHER’ LAND PLANTSLewis, L. A.Department of Ecology and Evolutionary Biology,University of Connecticut, 75 North Eaglevile Road, Storrs,CT 06269, USA

In addition to the more conspicuous embryophytegroup, numerous other green plant lineages havemade successful transitions to land. Phylogenetic anal-yses using molecular data indicate that these lineagesare primarily derived from freshwater ancestors, andinclude free-living and lichen photobiont algae in theclass Trebouxiophyceae, and several distinct lineagesof free-living algae in the class Chlorophyceae. In allcases, these independently derived land plants mustpossess adaptations for environments with reducedwater availability, oxidative stress, and different lightregimes than experienced by their aquatic ancestors.In the most extreme cases, these algae are living in veryarid habitats. Given the monophyly of green plantsand the evolution of independent terrestrial lineagesfrom aquatic ancestors, these lineages represent nat-ural experiments in the transition of green photosyn-thetic organisms to terrestrial living, and offer a richsource of taxa that can be compared experimentallywith the embryophytes.

ABSTRACTS 23

60CHLORORESPIRATION IN GREEN ALGAEISOLATED FROM DESERT CRUSTSLewis, L. A.∗, Cardon, Z. G. & Tyser, D.Department of Ecology and Evolutionary Biology,University of Connecticut, EEB, 75 North Eagleville Road,Storrs, CT 06269, USA

Photosynthetic organisms enduring extreme temper-atures, low water availability, or high light require pho-toprotective mechanisms to prevent sustained damageto photosynthetic machinery. Green microalgae liv-ing in desert crust communities of the south-westernUS experience all these environmental stresses, yetphotophysiological studies of green algae in the lit-erature have focused on only a handful of commonaquatic and marine species. We are examining the vari-ation in green algal photoprotective mechanisms thatis the result of natural selection acting independentlyin multiple lineages of highly diverse desert green al-gae (Chlorophyta) within the classes Chlorophyceaeand Trebouxiophyceae. We have found that unusu-ally extensive dark reduction of the plastoquinonepool is a prominent photophysiological feature amongthese desert algae; this reduction may be linked withenhanced chlororespiration. Recently, chlororespira-tion in higher plants has been linked through mu-tant analysis to control of the carotenoid syntheticpathway, heat stress, and starch metabolism amongother pathways, though the function of chlororespi-ration remains controversial. Given that green algaeand higher plants are monophyletic, analysis of poten-tial chlororespiration in desert green algae may helpdecipher the evolution of the chlororespiratory pro-cess as well as its potential role in photoprotection indesert habitats.

61BRANCHING MORPHOLOGY OFGAMETOPHYTES AND TETRASPOROPHYTESOF CERAMIUM CODICOLA IS RELATED TOPHASE AND REPRODUCTIVE STRUCTURESLewis, R. J.∗ & Lanker, M. D.Department of Biology, Wheaton College, Wheaton, IL60187, USA

Most red algae with a Polysiphonia-type life historyare regarded as having isomorphic phases. However,some show minor deviations in morphology, includ-ing differences in branching reported in female ga-metophytes and tetrasporophytes of Ceramium. Bysampling populations of Ceramium codicola, an epi-phyte of Codium fragile, it was possible to character-ize the morphology of female and male gametophytes

and tetrasporophytes. Branching pattern was char-acterized by the Strahler method, in which termi-nal branches are counted as primary branches, andhigher order branches are counted where lower orderbranches meet. Since Ceramium shows dichotomousbranching, this method can be used to characterizethe degree in which branching is dichotomous. Theangle of branching was also measured. Female game-tophytes had a higher ratio of primary to secondarybranches (3.6–5.1) than male gametophytes (2.5) andtetrasporophytes (2.5–2.6), which have a similar ratioto each other. This indicates that males and tetrasporo-phytes have a more dichotomous pattern of branchingwhile female gametophytes have more proliferativeprimary branches. The differences in branching pat-tern appear to be related to the location of reproduc-tive cells, which occur along the surface of branchesin male gametophytes and tetrasporophytes, but occurnear the apices in female gametophytes. The branch-ing angle of female and male gametophytes is simi-lar to each other, and greater than that of tetrasporo-phytes. Therefore, gametophytes and sporophytes dif-fer in branching angle.

62APOGLOSSEAE TRIB. NOV. (DELESSERIACEAE,RHODOPHYTA) BASED ON TWO MOLECULARDATASETS AND CYSTOCARP DEVELOPMENTLin, S.-M.1,∗, Fredericq, S.2 & Hommersand, M. H.31Research Department, National Museum of MarineBiology & Aquarium, 2 Houwan Road., Checheng,Pingtung 944, Taiwan; 2Department of Biology, Universityof Louisiana at Lafayette, Lafayette, LA 70504-2451;3Department of Biology, University of North Carolina atChapel Hill, Chapel Hill, NC 27599-3280, USA

The genus Apoglossum J. Agardh has traditionally beenplaced in the tribe Delesserieae. Our morphologi-cal observations on Apoglossum and the ‘Delesseria’species belonging to the resurrected genus Paraglos-sum from the Southern Hemisphere show that theypossess a distinct procarp. Apoglossum has two one-celled sterile groups that divide after fertilization andParaglossum consists of two one-celled sterile groupsthat do not divide after fertilization, but in which thenuclei divide to produce four to eight nuclei in theundivided sterile groups. In contrast, the procarp inD. sanguinea, the type species of the tribe Delesserieae,consists of two 2–6-celled sterile groups before fertil-ization and the number of sterile cells double after fer-tilization. The development of the carposporophyte inboth Apoglossum and Paraglossum is shown to be uniquein the subfamily Delesserioideae. The pit connectionsbetween the segments of the gonimoblast filaments

24 ABSTRACTS

broaden without fusion and secondary carposporan-gia are produced. This pattern is absent in other mem-bers of the Delesserioideae, but has been reported forthe tribes Myriogrammeae and Schizoserideae in thenew subfamily Phycodryoideae Lin, Fredericq et Hom-mersand. Based on both LSU rDNA and rbcL sequenceanalyses, the Delesserieae is restricted to species ofDelesseria and Membranoptera from the North Atlanticand North Pacific Oceans. In contrast, the species ofApoglossum and Paraglossum form a distinct cluster hav-ing a center of distribution in the Southern Hemi-sphere with only a few species, such as A. ruscifolium,reaching the Northern Hemisphere. In this study, de-tails of postfertilization development leading to thecystocarp are illustrated for the type species of Apoglos-sum and Paraglossum and a new tribe, the Apoglosseae,is recognized in the Delesseriaceae.

63PHRAGMOPLASTINS, THE TRENTEPOHLIALES,AND THE EVOLUTION OF THE CYTOKINESISIN GREEN PLANTSLopez-Bautista, J. M.1,∗ & Chapman, R. L.21Department of Biology, University of Louisiana atLafayette, Lafayette, LA 70504-2451; 2Department ofBiological Sciences, Louisiana State University, BatonRouge, LA 70803-1705, USA

Green plants have been shown to have a common an-cestor and to contain two lineages: the Chlorophytesand the Streptophytes, both encompassing represen-tatives of the original ‘green algae’. The phragmoplast-mediated cell division characterizes the land plants inthe Streptophyte lineage and some basal green algalorders (Coleochaetales, Charales and Zygnematales).However, a well-developed phragmoplast-type cell di-vision has been documented in two subaerial greenalgae (Cephaleuros parasiticus and Trentepohlia odorata)belonging to the order Trentepohliales, an orderthat molecular sequence data place unequivocallywithin the Chlorophytes (rather than Streptophytes).Is the phragmoplast-mediated cell division of theTrentepohliales a case for homology or nonhomol-ogy? In order to reveal the answer to this question,we are exploring the potential phylogenetic informa-tion inferred from gene sequences of phragmoplas-tin, a dynamin-like protein which has been demon-strated to be associated with cell plate formation dur-ing the phragmoplast-mediated cytokinesis in landplants. Primers were designed based on an availablephragmoplastin sequence from soybean, and yieldedPCR amplifications from the green algae (Trentepohliaand Cephaleuros), a bryophyte (Bazzania) and landplants (Glycine and Arabidopsis). The evolutionary his-

tory of the development of the phragmoplast may re-main in the analysis of the gene sequences for thisgroup of proteins.

64MOLECULAR SYSTEMATICS OF THESUBAERIAL GREEN ALGAL FAMILYTRENTEPOHLIACEAE (CHLOROPHYTA;TRENTEPOHLIALES) INFERRED FROM 18 SSUrDNA SEQUENCESLopez-Bautista, J. M.1,∗, Chapman, R. L.3, Rindi, F.2

& Guiry, M.31Department of Biology, University of Louisiana atLafayette, Lafayette, LA 70504-2451, USA; 2Departmentof Biological Sciences, Louisiana State University, BatonRouge, LA 70803-1705, USA; 3Department of Botany,Martin Ryan Institute, National University of Ireland,Galway, Ireland

Representatives of the monophyletic Trentepohlialesare widely distributed in the tropics, subtropics, andtemperate regions worldwide. They grow in soil, or areepilithic, epiphytic or endophytic. The family com-prises approximately 70 species placed in at leastfour genera (Trentepohlia, Cephaleuros, Phycopeltis andStomatochroon), with Trentepohlia sensu lato (includ-ing Printzina and Physolinum) accounting for half ofthe species in this family. PCR amplification and se-quencing of the 18 SSU rDNA of 18 isolates of theTrentepohliaceae were used to assess the monophylyof the genus Cephaleuros and to determine the phylo-genetic relationships among species of Trentepohliasensu lato. Distance, Parsimony, and Maximum Likeli-hood analyses indicate that Trentepohlia sensu lato isbasal and includes two species recently transferred toPhycopeltis (P. umbrina) and Printzina (P. lagenifera). Incontrast, Cephaleuros is a derived monophyletic clade.Analysis of isolates of C. virescens, from the USA, Tai-wan, and South Africa indicate that this taxon mayconsist of different species sharing a convergent mor-phology. The results of this study have implications forthe taxonomy of the genera.

65BIODIVERSITY AND POTENTIAL USE OFMARINE MACROALGAE FROM THE OFFSHOREOIL PLATFORMS IN THE GULF OF MEXICOLopez-Bautista, J. M.1,∗, Fredericq, S.1,Chapman, R. L.2 & Waters, D. A.21Department of Biology, University of Louisiana atLafayette, Lafayette, LA 70504-2451; 2Department ofBiological Sciences, Louisiana State University, BatonRouge, LA 70803-1705, USA

ABSTRACTS 25

In the north-western Gulf of Mexico, more than 3000oil and gas platforms are supporting a significant com-munity of marine organisms in an area wherein nat-ural hard substrata are scarce. This preliminary studyis designed to provide information on the algal com-ponent in terms of species diversity of marine red,brown and green macroalgae and cyanobacteria col-onizing these artificial reefs. The vertical, horizon-tal and seasonal distribution and relative abundanceare being documented. Taxonomic results are be-ing evaluated for potential use of some of the algaepresent as sources of natural products for the biotech-nological industry. The island character of this steelarchipelago in the north-western Gulf of Mexico pro-vides an ideal environment to test biogeographical re-lationships with adjacent floras. This research is sup-ported in part by the Minerals Management Service,US Department of the Interior.

66CHARACTERIZATION AND POSITION OF THEGENUS STENOGRAMME IN THEPHYLLOPHORACEAE (GIGARTINALES,RHODOPHYTA)Lopez-Bautista, J. M.1,∗, Fredericq, S.1, Lindstrom,S. C.2, Nelson, W. A.3 & Ramirez, M. E.41Department of Biology, University of Louisiana atLafayette, Lafayette, LA 70504-2451, USA; 2Departmentof Botany, #3529-6270, University Blvd., University ofBritish Columbia, Vancouver, BC, Canada V6T 1Z;3Museum of New Zealand Te Papa Tongarewa, P.O. Box467, Wellington, New Zealand; 4Seccion Botanica, MuseoNacional de Historia Natural, Santiago, Chile

The red algal genus Stenogramme was described byHarvey (1840) for entities having flattened, dichoto-mously branched thalli with cystocarps borne in nar-row, linear sori resembling an interrupted midrib onblades, and with isomorphic tetrasporophytes withscattered circular to irregular tetrasporangial ne-mathecia. In the current literature, the most com-mon species listed is Stenogramme interrupta (C. agardh)Montagne ex Harvey 1848, said to have a worldwidedistribution in temperate seas. DNA sequences fromthree molecular datasets (chloroplast-encoded rbcL,and nuclear-encoded ITS and LSU rDNA) instead re-veal that the genus is more species-rich than is cur-rently appreciated, and that several species go underthe name S. interrupta. The latter species, describedfrom Cadiz, Spain, is found to be restricted to the East-ern Atlantic. The name Stenogramme californica Harvey1840, the type species described from the Pacific coastof North America, is reinstated for members from

California and Oregon. S. rhodymenioides Joly et Alveal1969 is reinstated for the entity from Chile. The rangeof S. phyllophoroides (J. Agardh) Millar 1990 describedfrom northern NSW, Australia, is expanded to accom-modate the taxon from South Australia referred to asS. interrupta. S. leptophylla J. Agardh 1885 is a distinctSouth Australian species. A new name needs to beprovided for the New Zealand taxon. The genus alsocomprises a new entity (sterile) from Alaska, and a new(sterile) species from offshore Louisiana. Stenogrammeis a well-defined monophyletic genus, but its posi-tion within the Phylophoraceae remains equivocal.

67PHYSIOLOGICAL AND BIOCHEMICALRESPONSES OF TWO SEAWEEDS TO NUTRIENTOR LIGHT DEPRIVATIONLourenco, S. O.∗ & Berges, J. A.School of Biology and Biochemistry, Queen’s University ofBelfast, Belfast, Northern Ireland, UK

The algae Fucus vesiculosus (brown) and Enteromor-pha compressa (green) were cultured in long-term ex-periments in which natural seawater without nutri-ent enrichment was used, or in which the plantswere kept in complete darkness. Measurements ofvariable fluorescence (F v/F m), an indicator of pho-tosynthetic competence, showed a gradual decreaseof F v/F m in nutrient-deprivation experiments, vary-ing from 0.64 to 0.25 (E. compressa) and from 0.65to 0.40 (F. vesiculosus) after 6 months of cultivation.F. vesiculosus was virtually unaffected after more than2 months in darkness, showing values of F v/F m around0.65 throughout the experiments, but cultures ofE. compressa collapsed after 45 days in darkness. In bothspecies lower concentrations of chlorophyll a resultedof nutrient-deprivation experiments, decreasing threetimes in F. vesiculosus and 25 times in E. compressa bythe end of the experiments. F. vesiculosus cultured indarkness showed 50% more chlorophyll a than thecontrol, while plants of E. compressa kept in dark andin light showed similar values of chlorophyll a duringthe first 30 days of cultivation. The tissue-N contentof both species decreased dramatically in nutrient-deprivation experiments, establishing variations inC : N ratio from 20 : 1 to 79 : 1 (F. vesiculosus) and from8.6 : 1 to 75 : 1 (E. compressa). The algae showed smallvariations in C : N ratio throughout the experimentsin darkness. Such as previously identified for phyto-planktonic species, the variations in the physiologi-cal responses exhibited by the seaweeds tested suggestthat these conventional diagnostics of limitations may

26 ABSTRACTS

be misleading in natural algal assemblages, which arecomposed by mixed species. Gel electrophoretic is cur-rently being performed to identify possible proteinsthat may respond specifically to these experimentalconditions.

68DISTRIBUTION AND MORPHOLOGY OFDIATOMS IN HIGH ALTITUDE STREAMS ONKAUAI (HAWAII)Main, S. P.Biology Department, Wartburg College, Waverly, IA 50677,USA

Diatom samples collected from Kawaikoi Stream differin species composition and relative abundance fromthose in Kokee Stream. Kuwaikoi collects drainagefrom the Alakai Swamp, which developed on a 1200–1500 m elevation ridge of Mt. Waialeale extending at aright angle to the NE winds. Kokee lies about 2000 mfurther west at about 1100 m elevation. Frustulia andEunotia species characteristic of low conductivity wa-ters predominate. Greater diversity of Achnanthes, Nav-icula, Pinnularia and Surirella taxa occurs in the some-what more conductive waters of Kokee. The morpho-logical species observed bear a close, but not exact,resemblance to mainland taxa described in the litera-ture. Morphological variations are documented usinglight and scanning electron microscopy.

69PHYLOGENY OF THE CONJUGATING GREENALGAE (ZYGNEMATALES AND DESMIDIALES)BASED ON PLASTID AND MITOCHONDRIALGENE SEQUENCESMcCourt, R. M.1,∗, Park, J. 2, Hewitt, D. A.3 &Karol, K. G.41Department of Botany, Academy of Natural Sciences,Philadelphia, PA 19103; 2Department of Biology,University of Pennsylvania, Philadelphia, PA 19104;3Farlow Herbarium, Harvard University, Cambridge, MA02138; 4Cell Biology and Molecular Genetics, University ofMaryland, College Park, MD 20742, USA

The conjugating green algae (Order Zygnematalesand Desmidiales) are charophyceans, that is, they areamong the green algae most closely related to landplants. Compared to the five other groups of charo-phyceans (Mesostigma, Klebsormidiales, Chloroky-bales, Coleochaetales, Charales), the conjugatinggreens are by far the most diverse taxonomically(6 families, about 55 genera, 3–4000 species) and

very widespread in distribution (including commonspecies such as Spirogyra, Zygnema, Cosmarium, andStaurastrum). Thallus shape ranges from simple, ob-long unicells (saccoderm desmids, or Mesotaeni-aceae), to unbranched filaments of cells with smoothwalls (Zygnemataceae), to elaborately ornate anddeeply incised unicells or filaments made of such cells(placoderm desmids, in four families). Prior analy-ses of sequences of the chloroplast-encoded gene rbcL(1354 bp, or 95% of the gene) sampled from all sixfamilies showed that two of the traditional families(saccoderms and filamentous forms) are paraphyletic,i.e. they do not form two independent clades, al-though the component genera may together consti-tute a monophyletic group. In contrast, three fami-lies of placoderm desmids formed three monophyleticgroups within a larger clade. New analyses using par-tial sequences from the mitochondrial gene coxIII(608 bp, or 76% of the gene) for 21 species of con-jugating green algae from all six families supportedthe conclusions of the rbcL analysis, although boot-strap support for each gene along was weak for manybranches. The coxIII sequences are more variablethan rbcL and have proportionately more parsimony-informative sites (43% vs. 34%, respectively). Com-bining the two genes improved the resolution of theresulting tree: (1) bootstrap support increased forall branches, particularly in regards relationships ofplacoderm desmids; and (2) monophyly of a cladecontaining filamentous and saccoderm desmids wasstrongly supported. We conclude that phylogeny ofconjugating green algae will be much improved bysampling from additional genes.

70THE ROOTS OF LAND PLANTS: RECENTRESEARCH ON EARLY DIVERGING LINEAGESIN THE EVOLUTION OF HIGHER DRIER ALGAEMcCourt, R. M.1, Karol, K. G.2 & Delwiche, C. F.2,∗1Department of Botany, Academy of Natural Sciences,Philadelphia, PA 19103; 2Cell Biology & MolecularGenetics, University of Maryland, College Park, MD20742, USA

Recent multigene phylogenetic analyses of charo-phycean algae sensu Mattox and Stewart have ad-vanced our understanding of the relationships of thegreen algae that are most closely related to land plants.Several clades of green algae are monophyletic withland plants (i.e. liverworts, mosses, nonvascular andvascular plants that arose from an aquatic ancestor)to the exclusion of other green algae: Mesostigma(a flagellate unicell); the Chlorokybales (small pack-

ABSTRACTS 27

ets of cells); Klebsormidiales (unbranched filaments);Zygnematales (conjugating unicells, filaments, andcolonies); Coleochaetales (filamentous and parenchy-matous thalli); and Charales (branched filamentousthalli with complex nodal structure). The morpholog-ical and molecular diversity of the extant members ofthis nearly exclusively freshwater clade is remarkable.Moreover, the taxon diversity within clades is highlyasymmetric, having yielded several distinctive albeitsmall groups of green algae, as well as one of themajor evolutionary success stories on earth, viz. landplants. The most recent analysis (Karol etal. (2001)Science 294 : 2351–2353) of four genes from plastid, mi-tochondrial, and nuclear compartments strongly sup-port the sister relationships of Charales (stoneworts)to the most primitive land plants. The analysis alsoshows that within this clade there has been a trend to-ward increasing complexity of thallus form (from uni-cells, to filaments, to branching and parenchymatousthalli) and reproduction (absence of sexual reproduc-tion to iso- or anisogamy, to oogamy). Although themajor clades mentioned above are well supported bymolecular analyses, relationships among these groupsare less well-resolved, especially for the Klebsormidi-ales, Chlorokybales, and Mesostigma. This paper re-views the morphological and molecular evidence forthe relationships among and within these groups.More sequence data from a broader sampling of taxaat the base of the charophyceans (including perhapssome algae not now known to be charophytes) shouldprovide a clearer picture of the evolution of this groupand the reasons for its success.

71PHYLOGENETIC ANALYSIS OF THEMISCHOCOCCALES, TRIBONEMATALES, ANDVAUCHERIALES (XANTHOPHYCEAE) INFERREDFROM 18S rRNA GENE SEQUENCESMcElhinney, A.1,∗, Bailey, J. C.1 & Andersen, R. A.21Department of Biological Sciences and Center for MarineScience, UNC-Wilmington, 601 S. College Road,Wilmington, NC 28403; 2Bigelow Laboratory for OceanSciences, W. Boothbay Harbor, ME 04575, USA

The Xanthophyceae have traditionally been classifiedusing a phenetic classification system based upon veg-etative cell structure. Species belonging to the classare placed in one of six orders corresponding toamoeboid, coccoid, filamentous, flagellate, palmel-loid, or siphonous organization. Nuclear 18S rRNAgene sequences were determined for 29 species andaligned with 10 previously determined sequences. Par-simony and maximum likelihood trees inferred fromthese data imply that the orders Mischococcales (coc-

coid), Tribonematales (filamentous), and Vaucheri-ales (siphonous) are not monophyletic. The major-ity of species are divided between two clades definedby the presence or absence of a bipartite cell wall.Also, several families, particularly those placed in theMischococcales, are resolved as polyphyletic. Resultsindicate that coccoid and filamentous life forms mayhave arisen independently at least three times, andsome coccoid and filamentous life forms are resolvedas closely related. For example, Heterococcus (fil-amentous) is more closely related to Mischococcusand Pseudopleurochloris (coccoid) than it is to othermembers of the Tribonematales. Our data stronglysupport the contention that Bumilleriopsis and Pseu-dobumilleriopsis are congeneric with Bumilleria. Thesiphonous xanthophytes including Asterosiphon, Botry-dium, and Vaucheria probably do not form a mono-phyletic group although robust bootstrap support forthis conclusion is low. Our results indicate that thegeneric, familial, and ordinal classification of the Xan-thophyceae requires major revision.

72PHYLOGENETIC RELATIONSHIPS AMONGPEDIASTRUM sPP. AND HYDRODICTYON sPP.McManus, H. A.∗ & Lewis, L. A.Department of Ecology and Evolutionary Biology,University of Connecticut, 75 North Eagleville Road, U-43,Storrs, CT 06269, USA

Within the class Chlorophyceae, the family Hydrod-ictyaceae (order Sphaeropleales) consists of taxa thatform flat or net-like coenobia and reproduce asexu-ally by way of biflagellated zoospores. Two taxa withinthis family, Pediastrum and Hydrodictyon, share manyfeatures during development, especially the mannerof daughter colony formation. The colonies of Pedi-astrum differ from Hydrodictyon in that growth is pla-nar resulting in two-dimensional colonies, while three-dimensional nets are formed in Hydrodictyon. Stud-ies of the Chlorophyceae using morphological andultrastructural data, as well as molecular sequencedata, have supported the close relationship of Pedi-astrum and Hydrodictyon and they have remained inthe family Hydrodictyaceae throughout major clas-sification revisions. However, in these studies onlysingle species of Pediastrum (P. duplex) and Hydrodic-tyon (H. reticulatum) were included, therefore the ex-act relationship of these two taxa could not be ex-plored. Preliminary molecular data from a secondspecies of Pediastrum, P. boryanum, indicate that Hydro-dictyon may be derived from Pediastrum. In this anal-ysis, H. reticulatum resolves as sister taxon to P. duplexwith P. boryanum the ancestral taxon. Further molec-

28 ABSTRACTS

ular studies of the family Hydrodictyaceae allow ex-ploration of the relationships between Pediastrumspp. and Hydrodictyon spp., and assist in determiningwhether they are monophyletic. Preliminary analysesinclude H. reticulatum and H. africanum and severalspecies of Pediastrum, P. duplex, P. boryanum, P. tetras,P. biradiatum and P. simplex. An understanding of thephylogenetic relationships among the species of Pe-diastrum and Hydrodictyon will allow a more completecomparison of colony formation.

73RELATING PHYTOPLANKTON DYNAMICS TOENVIRONMENTAL FORCING IN THE LOWERST. JOHNS RIVER ESTUARY: A MULTIVARIATEASSESSMENTMillie, D. F.∗, Pigg, R. J., Bendis, B. J. &Steidinger, K. A.2Florida Marine Research Institute, Fish and WildlifeConservation Commission, 100 8th Avenue, St. Petersburg,FL 33701, USA

The St. Johns River, a 300-mile riverine and estu-arine system located along the north-eastern coast-line of Florida, has undergone extensive eutroph-ication through point and nonpoint source nutri-ent inputs. Moreover, recent reports of sudden fishkills and a high incidence of fish with lesions sug-gest the potential for harmful algal blooms. As partof a NOAA-funded project involving the characteri-zation of water quality parameters in relation to wa-ter inflows and nutrient inputs and the developmentof species-specific markers/probes for instrumental-based monitoring efforts, we used primer-based mul-tivariate analyses to examine the relationship betweenabiotic variables and both total and phylogenetic-group chlorophyll a concentrations (derived fromphotopigments and ChemTax matrix factorization ofdiagnostic carotenoids) during 2001. Seven samplingsites (identified through principle components ordi-nation of physical/chemical parameters as rangingfrom oligo- to mesohaline) were sampled intensivelyover 2-week periods on a seasonal basis. Chlorophyll aconcentrations typically ranged from 5 to 35 µg/L withthe greatest concentrations occurring at the oligo-haline sites. Phytoplankton assemblages were domi-nated by diatoms, cryptophytes, and cyanobacteria,and together typically comprised up to 90% of the to-tal chlorophyll a. Temporal variability in phytoplank-ton assemblages followed seasonal trends impacted bymeteorological and hydrological forcing. Spatial vari-ability in phylogenetic-group abundance (illustratedthrough multidimensional scalar ordination of sample

dissimilarity) was dramatic and associated with differ-ences in abiotic variables along the estuarine gradient.

74CHARACTERIZATION OF sufB SEQUENCESFROM NONGREEN PHOTOAUTOTROPHSMisner, I. J., Bailey, J. C.∗ & Freshwater, D. W.Department of Biological Sciences and Center for MarineScience, UNC-Wilmington, 601 S. College Road,Wilmington, NC 28403, USA

Partial sequences for the hypothetical chloroplastframe 24 (ycf24) were determined for 13 species of al-gae representing the classes Bacillariophyceae, Chrys-ophyceae, Pelagophyceae, Pinguiophyceae, Prymne-siophyceae, Raphidophyceae, and Xanthophyceae. Inmany databases ycf24 is considered an ATP-bindingcassette (ABC) transporter. Our analyses of trans-lated amino acid sequences demonstrate that thesesequences lack Walker A and B boxes, a conservedABC signature sequence motif, and transmembranedomains that characterize ABC transporters. Our data,as well as those of others, convincingly indicate thatycf24 is not an ABC transporter and is instead homolo-gous to the sufB gene first described from prokaryotes.The function of the sufB gene product in eukaryoticplastids is not known with certainty but it likely playsa key role in iron–sulfur (2Fe−2S) cluster formation.Our data, unpublished results and database searchesimply that sufB is plastid encoded in the ‘red’ plas-tid lineage, but has been transferred to the nucleusor lost within the streptophyte lineage. Phylogeneticanalyses of all available eucaryotic sufB sequences in-dicate that this gene is a useful marker for tracing theancestry of plastids and their hosts. For example, oursufB analyses indicate that the 35-Kb circular plastidgenome of Plasmodium falciparum is a member of the‘red’, not ‘green’, plastid lineage and was acquired viasecondary endosymbiosis. Our results also support thehypothesis that, despite their similarities, the plastidsof prymnesiophytes and heterokont algae were inde-pendently obtained by separate secondary endosym-biotic events.

75ARE ‘GREEN TIDES’ HARMFUL ALGALBLOOMS? ALLELOPATHIC PROPERTIES OFEXTRACTS FROM ULVA FENESTRATA ANDULVARIA OBSCURANelson, T. A.1,∗, Lee, D.1, Smith, B. C.2 & Prins, R.11Department of Biology, Seattle Pacific University, Seattle,WA 98119-1997; 2School of Aquatic and Fishery Sciences,University of Washington, Seattle, WA 98195, USA

ABSTRACTS 29

Toxic properties are rarely associated with macroalgalblooms. A few studies have demonstrated inhibitionof invertebrate larval development by extracts fromUlva spp. and we have observed substantial discol-oration of the seawater in small bays following massdesiccation-induced mortality of Ulvaria obscura. Weexamined the effects of extracts from Ulva fenestrataand U. obscura on enzyme systems, larval oyster devel-opment, Fucus gardneri zygote development, epiphyticdiatom growth, and growth of Ulva and Ulvaria. Ex-tracts from Ulvaria inhibited trypsin activity, but notpepsin or amyloglucosidase activity when tested at pHoptimized for each enzyme system (pH 8, 2, and 5.5,respectively). When tested at neutral to slightly alka-line pH (7 or 8), Ulvaria extracts also inhibited amy-loglucosidase activity. ‘Aged’ extract caused greaterenzyme inhibition than fresh extract. Maximum in-hibition occurred in 6-h-old-extract. Oyster larval de-velopment was inhibited by extracts from both algae,although the visible effects were much greater whenthe larvae were exposed to extracts of Ulvaria. Fucuszygote development was inhibited by extracts of bothspecies, although the effect was measurably greater inextracts from Ulvaria. Epiphytic diatom growth andgrowth of Ulva and Ulvaria were inhibited by extractsfrom both species. Thus, extracts from both Ulva fen-estrata and U. obscura have allelopathic properties, al-though the impacts are more widespread for Ulvariaextracts. These properties could alter competitive in-teractions by inhibiting germination or developmentof algal and animal competitors. Multiple toxins areprobably involved, since the two species tested causevisibly different responses.

76THE EFFECTS OF NITROGEN REGIME ONGROWTH, [CHN], [DMSP], [CHLOROPHYLL],[PROTEIN] AND NITROGEN UPTAKE RATE INULVARIA OBSCURA AND ULVA FENESTRATANelson, T. A.1,∗, Van Alstyne, K. L.2 & Ribarich, H.11Department of Biology, Seattle Pacific University, Seattle,WA 98119; 2Shannon Point Marine Center, 1900Shannon Point Road, Anacortes, WA 98221, USA

Ulva fenestrata and Ulvaria obscura are major con-stituents of ulvoid macroalgal blooms in the north-eastern Pacific. These blooms have been associatedwith a variety of environmental problems and arethought to be caused by increased nitrogen concentra-tion. We grew these algae at several nutrient concen-trations in incubator and seawater table experiments.Growth rate and the concentrations of DMSP, C, H,and N in the tissues were determined for both kinds of

experiments. Incubator experiments alone were usedto measure nutrient uptake rate, chlorophyll a and bcontent, and protein content (as determined by far-UV and bicinchoninic acid (BCA) techniques). In-creasing nutrient concentration caused significantlymore growth in the seawater table experiment butonly a trend toward greater growth in the incuba-tor. There was no significant interspecific differencein growth rate in the seawater table experiment, butUlva grew significantly faster than Ulvaria in the in-cubator experiment. Tissue nitrogen increased signif-icantly with increasing nutrient content in the growthmedium in the incubator experiment and showed asimilar (albeit not significant) trend in the seawatertable experiment. Ulvaria had higher tissue nitrogen,protein, and chlorophyll a concentrations than Ulvain all experiments. The ratio of chlorophyll b : a wasalso higher in Ulvaria than in Ulva. Far-UV and BCAtechniques yielded equivalent protein concentrationin Ulva but protein concentration determined by BCAwas 2.5 times higher in Ulvaria than when determinedby far-UV. Nutrient uptake rates were similar betweenboth species. DMSP concentration was not affected sig-nificantly by nutrient regime, but [DMSP] was higherin Ulvaria than in Ulva. These results help explainprevious observations of these species. Ulvaria gener-ally grows more slowly than Ulva because it requiresmore nitrogen to make chlorophyll and protein buthas similar nitrogen uptake rates. Ulvaria is also shadeadapted, while Ulva can acclimate to various condi-tions.

77THE EFFECTS OF THALLUS TOUGHNESS ANDNUTRITIVE QUALITY ON PALATABILITY OFANTARCTIC MACROALGAEPeters, K. J.1,∗, Amsler, C. D.1, Amsler, M. O.1,McClintock, J. B.1, Iken, K. B.1 & Baker, W. J.21Department of Biology, University of Alabama atBirmingham, Birmingham, AL 35294-1170; 2Departmentof Chemistry, University of South Florida, Tampa, FL33620, USA

Palatability of macroalgae can be affected by many dif-ferent factors including thallus toughness, nutritionalquality (carbohydrates, lipids, proteins, ash), and thepresence of deterrent secondary metabolites. Palata-bility bioassays were performed using two differentantarctic algal grazers (the antarctic rockfish Notothe-nia coriiceps and the sea star Odontaster validus). Thesedata were then compared to toughness and chemicalcomposition data. Toughness was determined using apenetrometer and a wide range of thallus toughness

30 ABSTRACTS

was observed in individuals of differing species as wellas of the same species. Some of the tougher individu-als required more than 30 N of force to cut throughthe thallus while others required less than 1 N to breakthrough. Each algal species is also being tested for per-cent composition of carbohydrates, lipids, proteins, aswell as ash. It is hypothesized that the algal species withgreater nutritional quality and/or less thallus tough-ness are more likely to be acceptable foods to con-sumers (NSF OPP9814538, OPP9901076).

78SURVIVAL OF CHLAMYDOMONAS SUBSEQUENTTO CRYOPRESERVATION IS PREVENTED BY ASUBSTANCE RELEASED FROM DAMAGED CELLSPiasecki, B.1,∗, Fan, Yang1, Diller, K. R.2 &Brand, J. J.11Molecular Cell and Developmental Biology, 2Departmentof Biomedical Engineering, University of Texas at Austin,Austin, TX 78712, USA

Storage of algae in liquid nitrogen offers a convenientway to permanently preserve many cultures with mini-mum genetic drift. We have successfully cryopreservedover 1400 strains in the Culture Collection of Algae atthe University of Texas (UTEX), but over one-fourthof UTEX cultures remain recalcitrant. Our previousstudies demonstrate that unicellular algae frozen ata high cell density (>2000000 cells/mL) do not sur-vive cryopreservation well. We now show that viabilityduring cryopreservation of Chlamydomonas reinhardtiiUTEX #89 at high cell densities is not affected bythe physical proximity of cells. Instead, when cellsare damaged, a small organic molecule(s) is pro-duced and released into the medium preventing cry-opreservation of other cells in the culture. HealthyC. reinhardtii cultures were treated with extracts pre-pared from damaged cells or culture medium sepa-rated from damaged cells, then cryopreserved by astandard method (Crutchfield etal. (1999) Eur J Phy-col 34: 43–52). Viability was measured after thawing bythe ability of a cell wall to preclude Evan’s blue dye,and was confirmed by quantitative agar plating. Theinhibitory substance from these fractions appears to af-fect living cells only during cryopreservation, but canbe produced from cells by a variety of treatments. Theinhibitor is heat-stable, but heating cells to 80 ◦C pre-cludes its production. The substance is stable whenseparated from cellular particulate matter, but grad-ually becomes inactive in the presence of cell mem-brane fractions. The inhibitor is a water-soluble andheat-stable organic compound(s), with a molecularmass less than or equal to 3500. Characterizing theinhibitory substance and the pathway that leads to its

formation may explain why most multicellular algaeremain recalcitrant to cryopreservation, and lead toprotocols that allow the cryopreservation of a broaderrange of organisms.

79PROTIST ORIGIN OF THE ULVOPHYCEAE(CHLOROPHYTA) REVEALED BY SSU RDNAANALYSES OF MARINE COCCOID GREENALGAEProschold, T.∗†, Surek, B., Marin, B. &Melkonian, M.Botanical Institute I, University of Cologne, Gyrhofstr. 15,D-50931 Koln, Germany

Traditionally, brackish and marine coccoid green al-gae are placed as isolated species of common treboux-iophycean or chlorophycean genera (e.g. Chlorella,Chlorococcum); exclusively the marine genera Chlorocys-tis and Halochlorococcum are characterized by quadri-flagellated zoospores and a ‘Codiolum-stage’ (char-acteristic for the Ulvophyceae) in their life histo-ries. In Chlorocystis cohnii, sexual reproduction couldonly be induced by presence of the tube-dwelling di-atom Berkeleya rutilans. Phylogenetic analyses of theSSU rDNA sequences of 32, mostly marine, coccoidor sarcinoid strains confirmed the monophyly of theUlvophyceae. The class contain 11 independent well-supported lineages; of which eight contain coccoidspecies. (1) The basal branch of the ulvophytes isthe Oltmannsiellopsis clade (in agreement with the or-der Oltmannsiellopsidales emend.) which containsthe quadriflagellated monads (O. viridis and O. uni-cellularis) and the type species of the coccoid genusHalochlorococcum (H. marinum). (2) The other speciesof Halochlorococcum (except H. saccatum) formed to-gether with Chlorocystis and Chlorella salina a signifi-cant clade corresponding to the order Chlorocystidalesin emended form. (3) Gomontia polyrhiza is closely re-lated to Urospora penicelliformis within the Acrosipho-nia group (Acrosiphoniales). (4) The sarcinoid Tri-chosarcina polymorpha and T. mucosa, and the freshwa-ter planctonic Helicodictyon planctonicum are memberof the Ulothrix clade together with filamenteous taxa.(5) The type species of Pseudoneochloris (P. marina)form together with three unidentified marine coc-coid strains an independent lineage within the Ul-vophyceae (called Pseudoneochloris clade). (6–8) Ig-natius tetrasporus (isolated from soil), the strain CCMP250 originating from desert soil and the marine strainCCMP 1293 isolated from Palau Islands representthree single lineages within the ulvophytes. Fromour results, the class Ulvophyceae can be subdividedtaxonomically into at least 11 orders (including the

ABSTRACTS 31

Ulvales, Cladophorales and Dasycladales) with thelargest biodiversity at the coccoid level.†Present address: Department of Molecular and Cell

Biology, Brown University, Providence, RI 02912, USA.

80CALCIFICATION AND DECALCIFICATIONDURING EPITHALLIAL CELL TURNOVER INCORALLINE RED ALGAEPueschel, C.1,∗ & Wegeberg, S.21Department of Biological Sciences, State University of NewYork at Binghamton, Binghamton, NY 13902, USA;2Marine Biological Laboratory, Strandpromenaden 5,3000 Helsingor, Denmark

Epithallial cells of the coralline red algae are charac-terized by unusual structural specialization, which in-clude deep invaginations of the distal cell surface, andby unique development, which culminates in senes-cence, shedding, and replacement of the cells. Elec-tron microscopic study of epithelial cell differentia-tion in morphologically and taxonomically disparatespecies suggests that the unusual features of epithelialcell structure and development stem from the fact thatthese dynamics occur within a calcified matrix. Distalwall ingrowths begin to form on the initial cells, cellswhose cleavage eventually gives rise distally to new ep-ithelial cells. After the distal wall ingrowths form, theoverlying crosswall becomes rich in organic material.For this organic wall material to be deposited into theexisting crosswall, the wall must first be decalcified;therefore, the presence of abundant organic materialin the crosswall provides a marker of localized decal-cification. We propose that the location and time oforigin of distal wall ingrowths indicate a connectionbetween the ingrowths and two coordinated processes:localized secretion of wall material, and decalcifica-tion of the overlying cell wall in preparation for themovement of the young epithelial cell into a new loca-tion relative to the surrounding calcified matrix. Thelarge plasmalemmal surface area associated with thedistal wall ingrowths allows for a greater abundanceof membrane-associated components, such as protonpumps, that could drive localized cell wall decalcifica-tion.

81INTERANNUAL VARIATION IN CORAL REEFPLANT COMMUNITIES OF CENTRAL BELIZERhodes, M. J. & Nelson, T. A.∗

Department of Biology, Seattle Pacific University, Seattle,WA 98119-1997, USA

Algal and seagrass community composition were mon-itored biennially along three transect lines in Belizefrom 1997 through 2001. Two sites were on South Wa-ter Caye. The first was on the seaward side, betweenthe reef crest and the caye. The second was on thelandward side of the caye. The third site was on LongCaye, Glover’s Reef Atoll. This transect line ran from acoral rubble filled embayment, through a small chan-nel (formed by hurricane Hattie in 1960, bisectingLong Caye), and into a seagrass meadow in the in-terior of the atoll. After a 38-year hiatus, hurricanesstruck Belize in 1998, 2000 and 2001, giving us theopportunity to examine changes in plant communitystructure before and after the storm sequence. Min-imal interannual changes were seen at South WaterCaye. The seagrasses at Long Caye were nearly elim-inated along the transect line due to burial by sand.Peak density of Thalassia testudinum at Long Caye wasover 60 shoots/m2 in 1997 and less than 2 shoots/m2

in 1999 and 2001. Halodule wrightii and Syringodiumfiliforme were both completely eliminated between1997 and 1999. Padina and Dictyota spp. flourished inthe embayment following the hurricane, but had beenvirtually absent prior to the sequence of storms. Fu-ture monitoring will be conducted to follow recoveryof the meadow and look for other long-term changes.

82SEQUENCE DIVERSITY OF THE GENE tufA INCOLEOCHAETE: AN ALGAL MODEL FORHORIZONTAL GENE TRANSFERRicker, J. M.∗, Lewandowski, J. D. & Delwiche, C. F.Cell Biology and Molecular Genetics, University ofMaryland – College Park, College Park, MD 20742-5815,USA

Studying the organellar gene transfer of tufA inColeochaete serves as a model system for understand-ing the effect of functional horizontal gene transfer onsequence conservation and divergence. Previous workindicates that tufA, which codes for protein synthesiselongation factor TU, is encoded only in the chloro-plast genome in most green algae, red algae, and glau-cocystophytes, but only in the nuclear genome of em-bryophytes. In the charophytes, the lineage of green al-gae that gave rise to embryophytes, tufA is present var-iously within the chloroplast and/or nuclear genome.This implies that tufA was probably transferred to thenucleus from the chloroplast after the charophytes di-verged from other green algae but before the diver-sification of the group. The chloroplast copy has un-dergone three separate fates within the charophytes:maintained in Charales, divergent in Coleochaetales,

32 ABSTRACTS

and lost in Zygnematales. Previous research indicatesthe presence of multiple nuclear copies and a highlydivergent chloroplast encoded tufA in Coleochaete or-bicularis. This research aims to isolate the chloroplast-encoded tufA from a representative panel of Coleochaetein order to characterize patterns of conservation in thedivergent chloroplast tufA. Putative chloroplast copiesof tufA have been isolated through PCR and subse-quent molecular cloning. By comparing the DNA se-quences from copies of the chloroplast-encoded tufAfrom a representative panel of Coleochaete, we hopeto gain insight into patterns of sequence conservationand from this infer the current function of the diver-gent chloroplast tufA.

83EFFECTS OF ENVIRONMENTAL PARAMETERSON THE GROWTH CHARACTERISTICS OFSYMBIODINIUM SPP. ISOLATED FROM CORALSRogers, J. E.1,∗, Davis, R. H.2 & Oliver, L. M.11US Environmental Protection Agency, Office of Researchand Development, National Health and EnvironmentalEffects Research Laboratory, Gulf Ecology Division, 1Sabine Island Dr, Gulf Breeze, FL 32561; 2UWF/EPAScience Training in Ecology Program, Gulf Breeze, FL, USA

Symbiodinium spp. were isolated from Porites porites(JR02F2 and RD03), Montipora capitata (JR12A7),Madracis mirabolis (RD02), Montastrea faveolata(RD04), Pocillopora damicornis (JR13E1), and anunknown coral (RD01). Growth rates and the distri-bution between motile gymnodinoid cells and sessilecoccoid cells were determined in 200 µL cultures in96-well dilution plates. Clones of each isolate weremaintained in L1 medium (prepared with 34 ppt ster-ile Gulf of Mexico water), at 26 ◦C with illuminationprovided at 100–150 mE/m2/s PAR (400–700 nm)during a 10 : 14 (light : dark) photoperiod. Underthese conditions, generation times of nearly onceper 24 h were observed for clones, JR02F2, RD01 andRD02, in log growth. Clone RD04 had a generationtime of approximately 5 days. The fastest growingclones produced the highest percentage of motilecells (>90) during the daylight portion of the diurnalcycle. Growth characteristics of selected clones wereexamined over a range of salinities, temperatures andPAR intensities. Salinities ranging from 25 to 45 ppthad little if any affect on growth rate. At salinitiesless than 25 ppt significant decreases in growth weregenerally observed; no growth was common at 5 and10 ppt. In most cases inhibitory effects of temperaturewere observed at temperatures greater than 29 ◦C. Forexample, generation times for JR02F2 were slightly

greater at 29 ◦C than 24 ◦C, but maximal growth rateswere reduced approximately 50–90% at temperaturesof 32 and 34◦C, respectively. The most sensitive clone,RD04, stopped dividing after two divisions at 29 ◦C.The growth rate of JR02F2 and RD01 reached a max-imum at PAR levels greater than 100 mE/m2/s andremained within a range of 0.75–0.85 divisions/dayup to 390 mE/m2/s.

84PHOTOPROTECTIVE COMPOUNDS INRICE-FIELD CYANOBACTERIASinha, R. P.∗ & Haeder, D.-P.Institute for Botany 1, Friedrich-Alexander University,Staudtstr. 5, D-91058 Erlangen, Germany

Cyanobacteria are cosmopolitan in distribution, form-ing a prominent component of microbial populationsin both aquatic as well as terrestrial ecosystems. Theyare the dominant microflora in rice-fields, where theysignificantly contribute to fertility as a natural biofer-tilizer. The fluence rates of UV-B radiation impingingon the natural habitats is of major concern since beingphotoautotrophic organisms, cyanobacteria dependon solar radiation as the primary source of energy.UV-B radiation causes reduction in growth, survival,pigment and protein content, heterocyst frequencyand fixation of carbon and nitrogen in cyanobacte-ria. However, a number of cyanobacteria synthesizewater soluble colorless mycosporine-like amino acids(MAAs) and the lipid soluble yellow-brown coloredsheath pigment, scytonemin to counteract the dam-aging effects of UV-B. Anabaena sp., Nostoc commune,Scytonema sp. and Lyngbya sp. were isolated from rice-fields in India and screened for the presence of pho-toprotective compounds. Spectroscopic and biochem-ical analyses revealed the presence of shinorine, abisubstituted MAA containing both glycine and ser-ine group with an absorption maximum at 334 nm inall cyanobacteria except Lyngbya sp. There was a circa-dian induction in the synthesis of this compound byUV-B. Polychromatic action spectra for the inductionof MAAs in Anabaena sp. and N. commune show the in-duction to be UV-B dependent peaking at 290 nm. An-other photoprotective compound, scytonemin, withan absorption maximum at 386 nm (also absorbs sig-nificantly at 300, 278, 252 and 212 nm) was detected inall cyanobacteria except Anabaena sp. In addition, twounidentified, water-soluble, yellowish and brownishcompounds with an absorption maximum at 315 nmwere recorded only in Scytonema sp. The spectral char-acteristics of these compounds neither matches withMAAs nor with scytonemin and seems to be a novel

ABSTRACTS 33

compound acting as an effective UV screens. In con-clusion, a particular cyanobacterium having photo-protective compounds may be a potent candidate asbiofertilizers for crop plants.

85PHYLOGENY OF KLEBSORMIDIUM(KELBSORMIDIALES; CHAROPHYTA) BASED ONrbcL , atpB , coxIII AND nad5 SEQUENCE DATASnyder, S. W.∗, Karol, K. G. & Delwiche, C. F.2106 H. J. Patterson Hall, Building 073, University ofMaryland, College Park, MD 20742-5815, USA

The charophycean order Klebsormidiales consists oftwo unbranched filamentous lineages, the fresh wa-ter Entransia and the semiterrestrial Klebsormidium.Molecular data have supported the close relationshipKlebsormidiales have with land plants. A monographexists for the European species of Klebsormidium; thismonograph provides a cladistic analysis of morpho-logical characteristics for eight Klebsormidium species,but a species level molecular phylogenetic analysishas not yet been performed for the group. We haveobtained 50 strains of Klebsormidium, representing 11morphological species, both from nature and fromculture collections. Phylogenetic analyses using rbcL,atpB, coxIII and nad5 gene sequence data from thesestrains and 40 outgroup sequences suggest that severaltraditional Klebsormidium species may not be mono-phyletic.

86A NOTE OF CAUTION ON USING ABSOLUTEMETHANOL CONCENTRATIONS AND LOWTEMPERATURES TO QUANTIFYMYCOSPORINE-LIKE AMINO ACIDS IN ALGAESommaruga, R.∗ & Tartarotti, B.Institute of Zoology and Limnology, University ofInnsbruck, Technikerstr. 25, 6020 Innsbruck, Austria

Mycosporine-like amino acids (MAAs), a family of UV-absorbing compounds, are widespread among manymarine and freshwater organisms, however, no stan-dard method to analyze these compounds is available.Consequently, protocols to extract MAAs largely dif-fer, for example, in the type of solvent, concentra-tions, temperatures, and times used. In this study,we tested whether the concentrations of MAAs areaffected by extraction at different temperatures andmethanol (MeOH) concentrations. Natural assem-blages of freshwater phytoplankton and the marinealga Porphyra sp. were used as test organisms. The

MAAs shinorine, palythine, MAA 331, asterina-330,and porphyra-334 present in the organisms examinedwere generally best extracted at 45 ◦C in 25% aque-ous MeOH. In Porphyra sp. and natural freshwaterphytoplankton, the mean total MAA concentrationsobtained with this protocol were, respectively, about13 and 3 times higher than when extracted in 100%MeOH at 4 ◦C. Depending on the organism exam-ined, both MeOH concentration and temperature af-fected extraction efficiency and final MAA concentra-tion. Our results stress the need for a priori testing theinfluence of these variables to assure that the highestconcentration is obtained without altering the qual-itative MAA composition. Based on these results, di-rect comparison of MAA concentrations reported inthe scientific literature should be done with caution.

87TRACING INVASIONS OF CAULERPA TAXIFOLIAWITH MOLECULAR MARKERSStam, W. T.1,∗, Meusnier, I.2, Destombe, C.2,Valero, M.2 & Olsen, J. L.11Departement of Marine Biology, Centre for Ecological andEvolutionary Studies, University of Groningen, theNetherlands; 2Labaratoire de Genetique et Evolution desPopulations Vegetales, UPRESA CNRS 8016, Universite deLille-1, France

Comparative sequence data from the rDNA ITS haveproven very useful in species identification and identi-fying major biogeographic groups of Caulerpa taxifolia.However, the low variability of the sequence, and theneed to screen hundreds of samples has limited itsutility for population level studies. Here we reporton the performance of two new markers suitable forpopulation level screening: the chloroplast rDNA 16Sintron-2 and intersimple-sequence-repeat fingerprints(ISSRs). A new analysis of ITS1 insertion–deletion pat-terns was also conducted using all available sequences.A number of new insights have emerged. First, the in-vasive aquarium strain (Mediterranean, California) isclearly from Brisbane, but the Brisbane populationsthemselves may be the result of an introduction fromNorthern Australia. Second, an analysis of the newdata in conjunction with an ITS1-insertion–deletionanalysis further suggests that the Mediterranean pop-ulations may be the result of not one, but two sepa-rate introductions. Third, intrapopulation genetic di-versity between invasive Mediterranean and ‘native’Australian populations revealed the occurrence oftwo divergent and widespread clades. The first cladegrouped nontropical invasive populations with coastal

34 ABSTRACTS

inshore populations of Australia while the second clus-tered all offshore/oceanic populations so far stud-ied. C. taxifolia, therefore exists as a complex of in-dependent ecotypes that probably represent nascentspecies. Fourth, despite our finding of nine distinctnuclear and five distinct chloroplast profiles, stronglinkage disequilibrium was found in most specimens,which indicates a predominance of asexual reproduc-tion. However, nucleo-cytoplasmic recombination wasdetected in one case, supporting hybridization bothwithin and between populations.

88THE CASE FOR A SINGLE-PLASTID ORIGINREVISITED: CONVERGENT EVOLUTION INORGANELLAR GENE CONTENTStiller, W. J.1,∗, Reel, D. C.1 & Johnson, J. C.21Department of Biology, Howell Science Complex N108,2Institute for Coastal and Marine Resources, East CarolinaUniversity, Greenville, NC 27858, USA

Three eukaryotic lineages generally are believed tohave plastids that are primary in origin; that is, de-scended directly from a cyanobacterial endosymbiont.The recovery of these plastids as a monophyletic groupin most molecular phylogenetic analyses, along withsimilarities in genome content and protein targetingmechanisms, have been cited as strong evidence insupport of the hypothesis of a single endosymbioticorigin of all plastids. Although these data indeed areconsistent with a single plastid origin, they also areconsistent with the proposition of multiple endosym-biotic origins. Each hypothesis requires certain evolu-tionary assumptions in order to be reconciled with allexisting data; at present, it is unclear which of theseassumptions most likely reflect the historical processthat gave rise to plastid diversity. Here we examine sim-ilarities in gene content among representatives of thethree primary plastid lineages, using as a control thegenome of a mitochondrion that almost certainly orig-inated as an independent endosymbiotic association.To minimize metabolic constraints on gene retentionwe focus on two datasets, ribosomal protein and trans-fer RNA genes, neither of which is tied directly tospecific organellar functions. Analyses of all possiblepair-wise comparisons among the three plastids andmitochondrion indicate that genomic similarities aremost consistent with convergent evolution due to con-straints on gene loss, rather than with hypothesizedshared evolutionary histories. We find no evidenceof phylogenetic signal in the pattern of gene lossoverlying this convergence. In light of these results,we address other lines of evidence and arguments

that have been raised in support of a single plastidorigin.

89ULTRASTRUCTURE AND PHYLOGENY OF ANEW SPECIES BELONGING TO THEPRYMNESIOPHYCEAETanczos, M. A.1,∗, Bailey, J. C.1 & Andersen, R. A.21Department of Biological Sciences and Center for MarineScience, UNC-Wilmington, 601 S. College Road,Wilmington, NC 28403; 2Bigelow Laboratory for OceanSciences, W. Boothbay Harbor, ME 04575, USA

Ultrastrucural and molecular data were used to ex-amine a new alga (CCMP2000) collected from theArabian Sea. Nonmotile vegetative cells are typicallyoblong to ovate, solitary and lack a gelatinous enve-lope. Ultrastructural analyses of these cells revealedthe presence of a nucleus located in the posterior por-tion of the cell. A single large Golgi body with numer-ous cisternae is located anterior to the nucleus as arenumerous profiles of mitochondria possessing tubu-lar cristae. Two peripheral plastids are present hav-ing immersed pyrenoids that are traversed by one ormore thylakoids. In some cells, the plastids are con-spicuously lobed forming finger-like extensions. Non-motile vegetative cells possess reduced mature andimmature flagella as well as a haptonema that are1 micron long or less. A distinct internal coveringand external wall surround the cell protoplasm. Theouter wall is apparently composed of simple scales, butthe composition (organic or mineralized?) of thesescales is unknown. The outer wall may form a pro-tuberance, or ‘foot’, at the posterior end of non-motile cells. Interestingly, many vegetative cells are in-fected by a labyrinthulid. Flagellate stages have beenobserved and possess roughly equal length flagellaand a haptonema. Phylogenetic analyses of nuclear18S rRNA and plastid-encoded rbcL genes indicateCCMP2000 is most closely related to Phaeocystis. How-ever, CCMP2000 does not fit the description of Phaeo-cystis, and therefore, probably warrants recognition asa new taxon.

90THE EFFECTS OF BIOGENICALLY ACTIVECOMPOUNDS ON CYCLOTELLA MENEGHINIANA(BACILLARIOPHYTA)Tedrow, O.∗, Julius, M. L. & Schoenfuss, H. L.Department of Biological Sciences, St. Cloud StateUniversity, St. Cloud, MN, USA

Biogenically active compounds have been discoveredin many surface water samples in Europe and North

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America. Wastewater effluent is identified as a majorsource of contamination and found to revert muchof the metabolic products of these biologically activecompounds back to their original form. This presen-tation explains methodology for determining the ef-fects of these contaminants through a newly developedbioassay, examining the physiological response of a di-atom to these compounds. Diatoms represent an im-portant aspect of the primary production community.They are a desirable food source over other mem-bers of the primary production community throughstorage of photosynthetically produced sugars in theform of lipids rather than starch. Therefore, membersof higher trophic levels selectively feed on diatomswhen present with other members of the primary pro-duction community. This study examines the effectsof select biogenically active compounds on the grossmorphology and physiological development of the di-atom species Cyclotella meneghiniana. Clearly, unicellu-lar protists such as diatoms are not susceptible to thesecontaminants in a manner directly analogous to thatexpressed in vertebrates. However, many of these com-pounds are lipophilic making them particularly effec-tive in entering the diatom cell membrane. Compar-ing cell density, lipid composition, fatty acid concen-trations, and the electron microscope ultra-structurein control and exposed cultures achieve this study’sexperimental objectives. This diatom was selected be-cause it commonly occurs in most freshwater environ-ments and has been the subject of other toxicologicalstudies. An adequate literature base also exists for eval-uating results of this experiment. The species growsrapidly and is easy to maintain in culture. The use ofa phytoplankton species as a test organism comple-ments other investigations involving vertebrate mod-els at the apex of the trophic hierarchy by consideringeffects at the base of the food web.

91DEVELOPMENT OF VALVES IN THE MARINEDIATOM GENUS TRIGONIUMTiffany, M. A.Department of Biology, San Diego State University, SanDiego, CA 92182, USA

Trigonium arcticum and T. formosum, marine diatomsepiphytic on Ectocarpus sp., were collected from thesublittoral off Point Loma, California. Forming valvesof these two sympatric species were studied usingscanning electron microscopy. The earliest develop-ing valve of T. arcticum encountered is a porous basallayer of silica, triangular, with pseudocelli just startingto form at each corner. The central annulus, the site

of the earliest valve formation, appears to be aboutthe size of a single areola. Early rimoportulae (labiateprocesses) are interspersed between central areolaeand are simple oval openings. Internally these formtheir labiate lip-like structures just before cribrum for-mation. Ridges form on the external side of the basallayer in a honeycomb pattern and produce the wallsof the loculate structures. The ridges expand outwarduntil cribrum formation is initiated. Small protuber-ances grow out from the edge of the ridge-like struc-tures and then become anvil-shaped as they grow to-ward the center of the pores and form the ‘roofs’ ofthe loculi. In external view of the mature valve, thepores are smoothly covered over except for a ring ofC-shaped slits. These cribra are flush with the surfaceof the valve. At about the time the cribra are com-pleting, rotae are formed within the porelli of thepseudocelli by extensions from two or three sides.The quadrangular T. formosum develops along muchthe same pattern. Differences are the less numerous,more centrally located rimoportulae, which possessexternal tubes and the formation of highly domedcribra.

92THE CHLOROPLAST GENOME SEQUENCE OFCHLOROKYBUS ATMOPHYTICUS: EVIDENCETHAT CHAROPHYCEAN GREEN ALGAE FROMAN EARLY DIVERGING LINEAGE ADAPTED TOTERRESTRIAL LIFETurmel, M.∗, Otis, C., De Cambiaire, J.-C., Pombert,J.-F. & Lemieux, C.Departement de biochimie et de microbiologie, UniversiteLaval, Quebec, Canada G1K 7P4

Land plants and green algae belonging to the Charo-phyceae sensu Mattox and Stewart form the Strep-tophyta, a lineage sister to the Chlorophyta whichcomprises most or all of the other green algae. Athird green plant lineage, at the base of the split ofthe Chlorophyta and Streptophyta, is possibly rep-resented by the green alga Mesostigma viride; how-ever, this remains controversial because some phylo-genetic analyses place Mesostigma within the Strepto-phyta. Five orders have been recognized in the Charo-phyceae: the Chlorokybales, Klebsormidiales, Zygne-matales, Coleochaetales, and Charales. Based on itssarcinoid thallus, the only species in the Chlorokybales,Chlorokybus atmophyticus, has long been regarded asthe earliest-diverging member of the Charophyceae.This rare species has been collected only in terres-trial habitats. In the present study, we have deter-mined the complete chloroplast DNA (cpDNA) se-

36 ABSTRACTS

quence (149 681 bp) of Chlorokybus to gain insight intoits phylogenetic position and also to better understandhow the chloroplast genome evolved in the Strepto-phyta. We have found that Chlorokybus cpDNA closelyresembles Mesostigma cpDNA in showing a high degreeof ancestral features. It displays a quadripartite struc-ture, encodes 138 genes (only two extra genes com-pared to Mesostigma cpDNA), and contains a singleintron (in trnL(UAA)). The gene order in Chloroky-bus cpDNA is similar to that of Mesostigma cpDNA;we estimate that 14 inversions would be requiredto convert the gene order of one alga into that ofthe other. Phylogenetic analyses of combined chloro-plast protein sequences from Mesostigma, Chlorokybus,other streptophytes, and a number of chlorophyteswill be presented. Overall, our results support theidea that the Chlorokybales represent an early diverginglineage.

93RECIRCULATING CULTURE FORCHONDRACANTHUS EXASPERATUSWaaland, J. R.Department of Botany, University of Washington, Seattle,WA 98195, USA

The red alga Chondracanthus exasperatus is a source ofthe phycocolloid carrageenan as well as an ingredi-ent referred to as ‘intralamellar gel’ in a recently de-veloped cosmetic formula (US Patent 6136 329). Thehigh value of the cosmetic product has sparked re-newed interest in cultivation of this species. Previouscultivation methods for this species include open wa-ter culture on nets and immersed cultivation in tankssupplied with flow-through pumped seawater. The in-stallation of a high capacity seawater supply, pump-ing and drain system is a major cost for flow throughsystems. Recirculating or re-use seawater systems thatminimize seawater turnover may offer significant costsavings over single-pass, flow through seawater sys-tems. In this research several options for minimizingseawater use have been tested: recirculating batch cul-ture in which nutrient replenished (carbon dioxideand mineral nutrients) natural or artificial seawater isused with minimal turnover and spray culture in whichplants are suspended in air saturated with nutrient re-plenished natural or artificial seawater medium. Smallvolume (<2 L), single-plant bioreactors and largermultiplant, 20, 80 and 320 L (sea water volume) im-mersion and spray systems have been developed andtested. Results from these systems will be presented.Research supported by Washington Sea Grant, Wash-ington Biotechnology Center and Soliv InternationalCorporation.

94PHYLOGENETIC ANALYSES OF THE SPECIESOF CHLOROSARCINOPSIS ANDNEOCHLOROSARCINA (CHLOROPHYCEAE)Watanabe, S.1,∗, Mitui, K.2, Nakayama, T.2 & Inouye,I.21Department of Education, Toyama University, Toyama930-8555; 2Institute of Biological Sciences, University ofTsukuba, Ibaraki 305, Japan

The genus Chlorosarcinopsis forms sarcinoid packagesof ?@ cells and reproduces by forming naked biflag-ellate zoospores. The genus Neochlorosarcina is distin-guished from Chlorosarcinopsis in having a thin cellwall around zoospores. We analyzed phylogenetic rela-tionships of seven species of Chlorosarcinopsis and fourspecies of Neochlorosarcina using 18S rDNA sequencedata. The species of the Chlorosarcinopsis were sepa-rated into two clades, and those of Neochlorosarcinaformed a monophyletic branch, which was far from theChlorosarcinopsis clades. Groover and Bold (1969) in-vestigated physiological abilities of species of Chlorosar-cinopsis (which included species of Neochlorosarcina),and showed that the species were roughly dividedinto three groups by usage of nitrogen and carboncomponents. These groups correspond two clades ofChlorosarcinopsis and a clade of Neochlorosarcina. Thisresult gave a phylogenetic meaning to the differencesin the physiological abilities, and supported the sepa-ration of Neochlorosarcina from Chlorosarcinopsis basedon a morphological attribute.

95DIGITAL ALGAE: A BOON TO RESEARCH ANDTEACHINGWaters, D. A.1,∗, Ciugulea, I. I.2 & Chapman, R. L.11Department of Biological Sciences, Louisiana StateUniversity, Baton Rouge, LA, USA; 2Department of Botanyand Microbiology, University of Bucharest, Romania

As part of a larger coastal ecology project, we have ini-tiated a web-accessible, digitized phytoplankton imageand taxonomy database of algae collected in a coastalwetland south of New Orleans, Louisiana. Examin-ing phytoplankton dynamics is a large component ofthe project, titled ‘Pulses—The Importance of PulsedPhysical Events for Watershed Sustainability in CoastalLouisiana’ (a joint NSF/EPA/USDA Water and Water-shed program). A total of 168 species of algae from 76genera in 8 phyla have been identified from the phyto-plankton samples, and 130 high-resolution (300 dpi)digital images taken. These taxonomic identificationdata are included in a database with collection infor-mation (i.e. location, date). Ecological data (i.e. tur-

ABSTRACTS 37

bidity, salinity, and nutrients such as nitrate and nitrite,ammonium, phosphorous, and silica) will be addedto the database. Having this information available onthe web is an important resource for continued re-search in coastal Louisiana and perhaps other regionswith similar ecosystems and hydrology. The databasecan also be a useful tool for teaching high school andcollege students. Microscopic phytoplankton are no-toriously difficult to identify, and the images can beused in conjunction with keys to help students con-firm their algal determinations. Students would alsobe able to see the main features of different groups ofalgae and learn some ecological aspects of the wetlandhabitat where they were collected. Please visit the website at chapmanlab.lsu.edu/digitalalgae. This projectwas supported in part by a grant from the Office ofSea Grant Development at LSU.

96ALGAL POLYUNSATURATED FATTY ACIDS:FOOD, PHEROMONES AND FOUL ODOURWatson, S.1,2,∗ & Janzen, L.21Environment Canada, NWRI, 867 Lakeshore Road,Burlington, Ontario L7R 4A6; 2Department BiologicalSciences, University of Calgary, 2500 University DriveN.W. Calgary, Alberta T2N 1 N4, Canada

Algal polyunsaturated fatty acids (PUFAs) are knownto be high-energy, often-essential resources to freshwa-ter aquatic food webs. On the other hand, high PUFAcell content in some algal taxa has been linked with theproduction of derivatives that may act as pheromones,allelogens or toxins. It has been known for some timethat these compounds function in marine chemicalecology, but recent evidence indicates that they mayplay similar roles in freshwater ecosystems. This paperpresents field and laboratory studies of planktonic andperiphytic communities from freshwater systems, andshows that these communities are rich sources of cer-tain PUFAs and derivatives which may function in bothpositive and negative foodweb interactions. This alsohas important implications for surface water quality,as these compounds are potent sources of rancid fishyodours.

97THE USE OF LIQUIDCHROMATOGRAPHY–MASS SPECTROMETRY(LC–MS) IN THE IDENTIFICATION ANDCHARACTERIZATION OF MYCOSPORINE-LIKEAMINO ACIDS (MAAS)Whitehead, K.∗ & Hedges, J. I.School of Oceanography, Box 355351, University ofWashington, Seattle, WA 98105, USA

Mycosporine-like amino acids (MAAs) are a class ofUV-absorbing compounds synthesized by a variety ofmarine and freshwater algae and cyanobacteria withabsorption maxima between 310 and 360 nm. To date,∼25 different MAAs have been characterized with sev-eral new compounds identified each year. A majordifficulty in the analysis of MAAs is the lack of com-mercial standards. Thus far, MAAs have been identi-fied by their retention time and UV absorption afterseparation via high performance liquid chromatog-raphy (HPLC). Complementing the HPLC methodwith the use of mass spectrometry (LC–MS) offersgreater sensitivity and reduces the hindrance standardunavailability presents by providing detailed molec-ular information (molecular weight and fragmenta-tion patterns). The molecular weight informationadds one more level to our ability to characterizeMAAs and any new UV-absorbing compounds discov-ered. The fragmentation patterns obtained via LC–MSalso contributes diagnostic information for structureelucidation and identification. LC–MS analysis hasbeen used to examine UV-absorbing compounds inmethanolic extracts from Phaeocystis antarctica. Whensamples were analyzed using isocratic HPLC elu-tion, several UV-absorbing peaks were eluted. How-ever, molecular weight and fragmentation patterns ofsome UV-absorbing compounds were not commiser-ate with those expected for MAAs. Additionally, pa-lythenic acid was detected rather than mycosporine-glycine : valine as had been previously reported forthis organism. Gradient elution provided further sep-aration into MAA and ‘unknown’ groupings. The un-known UV-absorbing component has longer retentiontimes and different mass spectral characteristics withwavelength maxima between 315 and 325 nm. Thisstudy benefited immensely by the addition of MS tech-niques, as many of the compounds would have re-mained either misidentified or entirely unidentified.The increased analytical capability afforded by LC–MSallows us to further investigate the structural diversityand biochemistry of MAAs aiding our study of the roleMAAs play as sunscreen agents.

98MYCOSPORINE-LIKE AMINO ACIDS INHARMFUL MARINE MICROALGAEWulff, A.∗ & Appelgren, M.Department of Marine Ecology, Marine Botany, GoteborgUniversity, Sweden

Two current environmental issues are the increas-ing occurrence of harmful algal blooms and theincreasing level of ultraviolet radiation. The objec-tive of this ongoing project is to investigate whether

38 ABSTRACTS

there is a coupling between these two phenomena,i.e. to test the hypothesis that UV-B radiation func-tions as a selective pressure favoring surface-bloomingtoxic/harmful marine microalgal species capable ofproducing UV-absorbing compounds (mycosporine-like amino acids, MAAs). A series of experimentswere designed to test if the light environment in-duces the production of MAAs. Treatments were PARwith and without the addition of UV-B radiation. Pre-liminary results show a different response for dif-ferent species. Most species increased their produc-tion of MAAs when exposed to an increased PAR in-tensity (300 µmol photons/m2/s) and in, e.g. Alexan-drium ostenfeldii and Gyrodinium aureolum a further in-crease was observed upon exposure to UV-B radiation.The content and composition of MAAs for a num-ber of potentially harmful marine microalgae will beshown. In addition, the outcome of small changes inthe HPLC method used will be discussed.

99HIGHLIGHTS OF RECENT COLLECTIONS OFMARINE ALGAE FROM THE SULTANATE OFOMANWynne, M. J.Department of Ecology and Evolutionary Biology,University of Michigan, Ann Arbor, MI 48109, USA

Collections of benthic marine algae made over thepast 3 years on the Dhofar coast of the Sultanateof Oman have continued to provide a more com-plete picture of the floristic affinities of this up-to-now poorly explored region. This Algal Biodi-versity Project of Oman was funded by the BritishGovernment’s Darwin Initiative grant for the ‘Sur-vival of Species’ and managed by HTS Develop-ment Ltd., of the UK. A rich and floristically com-plicated flora is emerging, with connections to sub-tropical and warm temperate regions. Many new al-gal taxa have been discovered and described, andnumerous new records for Oman or for the IndianOcean have been reported. Some species newly re-ported for Oman (and the Indian Ocean) had previ-ously been known from Japan (Distromium decumbens,Kallymenia crassiuscula, Dudresnaya japonica, and Chon-dria crassicaulis). Sporochnus pedunculatus and Pedobe-sia simplex had been known from the North Atlanticand the Mediterranean and are new records for the In-dian Ocean. Some new species of red algae have beendescribed, such as a Dipterocladia and a Plocamium.Some brown algal novelties have also been discovered,including new species of Turbinaria and Jolyna, and anew genus of Chordariaceae. The macroalgal flora of

southern Oman is rich with representatives of Codium,Scinaia, Galaxaura, Melanothamnus, and the familiesGelidiaceae and Dictyotaceae. Several representativemarine algae from southern Oman will be depictedand discussed.

100THE CENTRAL AMERICAN ISTHMUS:IMPLICATIONS FOR INTRASPECIFICPHYLOGENY AND BIOGEOGRAPHY OF APANTROPICAL GREEN ALGAWysor, B.Department of Biology, University of Louisiana at Lafayette,P.O. Box 42451, Lafayette, LA 70504-2451, USA

An intraspecific phylogenetic study was undertakento resolve the evolutionary relationship of isolates ofthe green alga Phyllodictyon anastomosans (Harv.) Kraftet Wynne that occur on Atlantic and Pacific coastsof the Central American Isthmus. Patterns of vicari-ance related to the emergence of the Central Ameri-can Isthmus were evident, but numerous examples ofrecent trans-oceanic and trans-isthmian dispersal ob-scured the underlying pattern. This study, one of thefirst studies to assess the impact of the emergence ofthe Central American Isthmus in seaweed phylogeog-raphy, provided an ideal opportunity to estimate therate of sequence evolution using a single time point.Using this newly calibrated molecular clock the tim-ing of an historical introduction across the isthmus isshown to be concordant with a shallow water breachof the isthmus dated at approximately 2.3–2.0 millionyears ago. This work contributes to a growing body ofliterature that suggests marine algae are fairly success-ful at dispersing over long distances in recent times.

101COMPARATIVE PHYLOGEOGRAPHY OFRETICULATE CLADOPHORALEAN ALGAEWysor, B.1,∗, Kooistra, Wiebe H. C. F.2 & Fredericq,Suzanne1

1Department of Biology, University of Louisiana atLafayette, P.O. Box 42451, Lafayette, LA 70504-2451,USA; 2Stazione Zoologica ‘Anton Dohrn’, VillaCommunale I, I-80121 Naples, Italy

The study of species distributions requires well-defined species concepts and well-resolved speciesrelationships. Ideally, the biogeography of taxa willbe concordant with their genetic signatures identi-fied by molecular markers. For groups with poorlydefined species (or generic) concepts, taxon sam-pling can be highly problematic because morpholog-

ABSTRACTS 39

ical plasticity may deter sample collection of a specieswhen it expresses alternative morphologies. This maygive the impression of a disjunct species distributionwhen it is actually continuous across a particular geo-graphic range. Likewise, morphological convergencecan obscure biogeographic patterns, but with the op-posite effect. To avoid taxon sampling problems ina phylogeographic study of the green alga Phyllodic-tyon anastomosans (Harv.) Kraft et Wynne, a speciesknown for its morphological variability, we includedtaxa across four genera (Boodlea G. Murray & DeToni, Cladophoropsis Børgesen, Phyllodictyon J. E.Gray, Struveopsis Rhyne et H. Robinson) often char-acterized by overlapping character states. The inclu-sion of isolates outside the taxonomic boundaries ofP. anastomosans allowed us to extend earlier phylogeo-graphic studies of the closely related C. membranacea(C. agardh) Børgesen and compare patterns betweentwo closely related taxa. Results suggest that the Cen-tral American Isthmus represents a formidable butpermeable barrier to dispersal.

102THE AQUACULTURE OFPORPHYRA LEUCOSTICTA (RHODOPHYTA) FORAN INTEGRATED FINFISH/SEAWEEDRECIRCULATING AQUACULTURE SYSTEM INAN URBAN APPLICATIONYarish, C.∗, He, P., Carmona, R., Liu, S., Kraemer,G., Neefus, C., Chopin, T., Nardi, G., Curtis, J.,Lonergan, S. & Trupp, P.Department of Ecology and Evolutionary Biology,University of Connecticut, One University Place, Stamford,CT 06901-2315, USA; Fisheries College, ShanghaiFisheries University, Shanghai 200090, China;Environmental Research Institute, University ofConnecticut, The Longley Building, 270 Middle Turnpike,Route 44, U-210, Storrs, CT 06269-3210, USA; BiologyDepartment, State University of New York, Purchase, NY,USA; Department of Plant Biology, Office of Biometrics,University of New Hampshire, Durham, NH 03824, USA;Department of Biology, Center for Coastal Studies andAquaculture, The University of New Brunswick, SaintJohn, New Brunswick E2L 4L5, Canada; GreatBayAquaculture, LLC, 153 Gosling Road, Portsmouth, NH03801, USA; Bridgeport Regional Vocational AquacultureSchool, 60 St. Stephen Road, Bridgeport, CT 06605, USA

Aquaculture represents an excellent opportunity tohelp rejuvenate blighted coastal urban areas on thenorth-east coast. Aquaculture requires relatively littlespace, often acquired at reduced cost in ungentrifiedcity areas, and can represent an attractive, environ-

mentally benign form of commerce. However, finfishand shellfish aquaculture operations are a source ofan effluent with high concentrations of dissolved inor-ganic nutrients (N, P). To prevent eutrophication, theEPA is developing stringent guidelines for the releaseof N and P into coastal waters. An integrated recir-culating aquaculture system, coupling the growth ofseaweed and fish, can solve these problems for urbanaquaculture facilities; not only is the effluent remedi-ated but an additional multiproduct, high-value cropcan be generated. One tank-based (on land) marineaquaculture operation is GreatBay Aquaculture, LLC(Portsmouth, NH), a land-based hatchery and grow-out facility for high value summer flounder and cod.Our work is to develop an integrated finfish/seaweedrecirculating aquaculture system (RAS) suitable forurban aquaculture. Our RAS system will integratethe culture of summer flounder and native speciesof seaweed (i.e. Porphyra). BRVAS students are work-ing along side undergraduate and graduate studentsin the construction and operation of these systems.There are at least seven recognized species of Porphyrain the north-east. We have begun mesoscale evaluationof P. leucosticta, since it may be a good candidate forthe food (sushi) and for r-phycoerythrin industries.The mass culture techniques (in both free cultureand attached to nets) for this Porphyra species are de-veloping. We will report on the mass seeding technolo-gies that we have developed and the specific growthrates of P. leucosticta at the BRVAS culture facilities.

103MOLECULAR CHARACTERISTICS OF CAULERPA(CHLOROPHYTA) POPULATIONS IN TAIWANYeh, W.-J.∗, Lin, S.-C. & Chen, G.-Y.Department of Aquaculture, National Pingtung Universityof Science and Technology, Pingtung 912, Taiwan

Tropical and subtropical Caulerpa species are epi-demic to northern and southern Taiwan seashore.We here describe the molecular characteristics ofrRNA gene, including the internal transcribed spacers(ITS) in this genus and a comparison was made withassociated species sequences registered in the Gen-Bank. A total of nine specimens (C. racemosa var. mi-crophysa, macrophysa, peltata, laetevirens, C. serrulata andC. elongata) were investigated. Samples were collectedand distinguished first from morphological character-istics. The genomic DNA was individually extractedusing CTAB protocol. To amplify the 18S rRNA, ITS1,5.8S rRNA, ITS2 and 28S rRNA sequences, a primerpair NS7 and ITS4, sequences located in nuclear rRNAregion, was used. The range of 980–1100 bp DNA frag-

40 ABSTRACTS

ment from genomic DNA of individual plant was gen-erated from polymerase chain reaction (PCR). Ampli-fied fragments were sequenced automatically with ABIsequencer. The sequences were aligned with those ofother Caulerpa species retrieved from the GenBank.The phylogenetic tree was constructed using Clustalmethod. The comparison of whole sequence and 18SrRNA and ITS1 region among these specimens showsthat the interspecies divergence within C. racemosa var.microphysa, macrophysa, peltata and laetevirens is largerthan those of intraspecies of C. taxifolia, C. serrulataand C. elongata. It is supposed that they (C. racemosa var.microphysa, macrophysa, peltata and laetevirens) shouldbe in the position of different species in Caulerpa genusfrom the present rRNA sequences analysis. The se-quences of 5.8S region are shown more conserve thanthat of 18S region. The identity of ITS1 and ITS2regions in present species are low, comparing withC. taxifolia, C. maxicana.

104THE MONOPHYLETIC ORIGIN OF THEPERIDININ-, ANDFUCOXANTHIN-CONTAININGDINOFLAGELLATE PLASTID THROUGHTERTIARY REPLACEMENTYoon, H. S.∗, Hackett, J. D. & Bhattacharya, D.Department of Biological Sciences, University of Iowa, IowaCity, IA 52242, USA

The dinoflagellates contain diverse plastids of uncer-tain origin. To determine the origin of the peridinin-and fucoxanthin-containing dinoflagellate plastid, wesequenced the plastid-encoded psaA, psbA, and rbcLgenes from various red and dinoflagellate algae. ThepsbA gene phylogeny, which was made from a datasetof 15 dinoflagellates, 22 rhodophytes, five crypto-phytes, seven haptophytes, seven stramenopiles, twochlorophytes, and a glaucophyte as the outgroup, sup-ports monophyly of the peridinin-, and fucoxanthin-containing dinoflagellates, as a sister group to thehaptophytes. The monophyletic relationship with thehaptophytes is recovered in the psbA + psaA phy-logeny, with stronger support. The rubisco tree uti-lized the ‘Form I’ red algal type of rbcL and includedfucoxanthin-containing dinoflagellates. The dinoflag-ellate + haptophyte sister relationship is also recov-ered in this analysis. Peridinium foliaceum is shown togroup with the diatoms in all the phylogenies. Basedon our analyses of plastid sequences, we postulatethat: (1) the plastid of peridinin-, and fucoxanthin-containing dinoflagellates originated from a commonancestor; (2) the ancestral dinoflagellate acquired its

plastid from a haptophyte though a tertiary plastidreplacement; (3) ‘Form II’ rubisco replaced the an-cestral rbcL after the divergence of the peridinin-,and fucoxanthin-containing dinoflagellates; and (4)we confirm that the plastid of P. foliaceum originatedfrom a Stramenopiles endosymbiont.

105THE SINGLE, ANCIENT ORIGIN OF CHROMISTPLASTIDSYoon, H. S.1, Hackett, J. D.1, Pinto, G.2 &Bhattacharya, D.1,∗1Department of Biological Sciences and Center forComparative Genomics, University of Iowa, 239 BiologyBuilding, Iowa City, IA 52242, USA; 2Dipartimento diBiologia vegetale, Universita Federico II, Via Foria 223,80139 Napoli, Italy

Phylogenetic comparisons suggest that plastid pri-mary endosymbiosis, in which a single-celled protistengulfs and ‘enslaves’ a cyanobacterium, likely oc-curred once and resulted in the primordial alga. Thisphotosynthetic cell diversified, through vertical evo-lution, into the ubiquitous green (Chlorophyta) andred (Rhodophyta) algae, and the more scarce Glau-cophyta. However, some modern algal lineages havea more complicated evolutionary history involving asecondary endosymbiotic event, in which a protistengulfed an existing eukaryotic alga (rather than acyanobacterium), which was then reduced to a sec-ondary plastid. Secondary endosymbiosis explains themajority of algal biodiversity, yet the number andtiming of these events is unresolved. Here we ana-lyzed a five-gene plastid dataset to show that a diversegroup of chlorophyll c-containing protists compris-ing cryptophyte, haptophyte, and stramenopiles algae(Chromista) share a common plastid that most likelyarose from a single, ancient (about 1260 million yearsago) secondary endosymbiosis involving a red alga.This finding is consistent with C. monophyly and impli-cates secondary endosymbiosis as a driving force inearly eukaryotic evolution.

106ACCUMULATION OF TRIACYLGLYCEROLS INHAEMATOCOCCUS PLUVIALIS IS CORRELATEDWITH THAT OF ASTAXANTHIN ESTERSZhekisheva, M.∗, Boussiba, S., Khozin-Goldberg, I.,Zarka, A. & Cohen, Z.Microalgae Biotechnology Laboratory, The Jacob BlausteinInstitute for Desert Studies, Ben-Gurion University of theNegev, Sede-Boker Campus 84990, Israel

ABSTRACTS 41

The chlorophyte Haematococcus pluvialis accumulateslarge quantities of astaxanthin under stress conditions.Under either nitrogen starvation or high light, theproportion of each picogram of astaxanthin was ac-companied by that of 5 or 3–4 pg of fatty acids, re-spectively. In both cases, the newly formed fatty acids,consisted mostly of oleic (up to 34% of fatty acidsin comparison to 13% in the control), palmitic andlinoleic acids, were deposited mostly in triacylglyc-erols. Furthermore, the enhanced production of oleicacid was linearly correlated with that of astaxanthin.Astaxanthin which is mostly monoesterified, is de-posited in globules made of triacylglycerols. We sug-gest that the production of tailor-made oleic acid-richtriacylglycerols on the one hand and the esterifica-tion of astaxanthin on the other hand, enable the oilglobules to maintain the high content of astaxanthinesters.

107MYCOSPORINES: DETECTIONMETHODOLOGIES AND ASSESSMENTZimba, P. V.1,∗ & Wulff, A.21USDA/ARS, P.O. Box 38, Stoneville, MS 38776, USA;2Department of Marine Ecology, Goteborg University, P.O.Box 461, Goteborg, Sweden

Mycosporine-like amino acids (MAAs) are found in avariety of prokaryotic and eucaryotic algae, as well ashigher plants, fungi, and animals. These compoundsfunction as a photoprotective sunscreen to preventultra-violet light damage. MAAs may thus be one of thecompetitive advantages that facilitated developmentof ozone (by oxytrophs), and thereby may be a com-petitive advantage for the proliferation of cyanobacte-ria and other harmful algal species. Numerous diffi-culties exist with assessment of MAAs, including iden-tification of the compounds, conversion of isomers

during HPLC preparation as a result of pH shifts, aswell as the ecological implications of the presence,concentration, and forms of these compounds (seeJ Phycology 1999; 35, for relevant papers). This sym-posium will provide opportunities for intercalibrationof laboratories involved in MAA analyses, suggestionsregarding standardization of extraction protocols, aswell as results from field- and laboratory-based studies.

108MYCOSPORINE-LIKE AMINO ACIDINTERCALIBRATION EFFORT USINGREPLICATE SAMPLESZimba, P. V.1,∗ & Boue, S.21USDA/ARS, P.O. Box 38, Stoneville, MS 38776;2USDA/ARS, 1100 Robert E. Lee Blvd., New Orleans, LA70124, USA

The measurement of mycosporine-like amino acids(MAAs) has several inherent problems, including thelack of commercial standards for identification andquantification. This symposium provided the oppor-tunity to coordinate analyses with six laboratories ac-tively involved in MAA research. Two samples wereprovided to each laboratory and included freeze-driednori (Porphyra sp.) and a freeze-dried (filtered) sam-ple of the cyanobacteria Microcystis aeruginosa Kutzing.Each laboratory provided extraction methodologies,chromatograms of the identified peaks, as well as es-timates of the concentration of each analyte. All labo-ratories were able to identify major chromatographiccomponents of the samples (Porphyra: shinorine, por-phyra, mycosporine 2-glycine, asterina, palythine; Mi-crocystis: shinorine, porphyra). Sequential cold (4 ◦Cfor 18 h) and hot (45 ◦C for 2 h) extractions of thesame sample resulted in differing analyte recovery.Several currently unidentified compounds were ob-served in freshwater samples.