Six new Actinella (Bacillariophyta) species from Papua New ... · Six new Actinella (Bacillariophyta) species from Papua New Guinea, Australia and New Zealand: further evidence for

This article was downloaded by: [193.191.134.1]On: 16 January 2012, At: 23:52Publisher: Taylor & FrancisInforma Ltd Registered in England and Wales Registered Number: 1072954 Registered office: Mortimer House,37-41 Mortimer Street, London W1T 3JH, UK

European Journal of PhycologyPublication details, including instructions for authors and subscription information:http://www.tandfonline.com/loi/tejp20

Six new Actinella (Bacillariophyta) species from PapuaNew Guinea, Australia and New Zealand: furtherevidence for widespread diatom endemism in theAustralasian regionKoen Sabbe a , Koenraad Vanhoutte a , Rex L. Lowe b , Elizabeth A. Bergey c , Barry J.F. Biggsc , Steve Francoeur d , Dominic Hodgson e & Wim Vyverman aa Department of Biology, Laboratory of Protistology & Aquatic Ecology, University of Gent, K.L. Ledeganckstraat 35, 9000 Gent, Belgiumb Department of Biological Sciences, Bowling Green State University, Bowling Green, OH43403, USAc National Institute of Water & Atmospheric Research Ltd, Kyle Street, Riccarton,Christchurch, PO Box 8602, New Zealandd Biological Sciences Department, University of Alabama, Box 870206, A-122 Bevill,Tuscaloosa, AL 35487-0206, USAe British Antarctic Survey, High Cross, Madingley Road, Cambridge CB3 OET, UK

Available online: 03 Jun 2010

To cite this article: Koen Sabbe, Koenraad Vanhoutte, Rex L. Lowe, Elizabeth A. Bergey, Barry J.F. Biggs, Steve Francoeur,Dominic Hodgson & Wim Vyverman (2001): Six new Actinella (Bacillariophyta) species from Papua New Guinea, Australia andNew Zealand: further evidence for widespread diatom endemism in the Australasian region, European Journal of Phycology,36:4, 321-340

To link to this article: http://dx.doi.org/10.1080/09670260110001735478

PLEASE SCROLL DOWN FOR ARTICLE

Full terms and conditions of use: http://www.tandfonline.com/page/terms-and-conditions

This article may be used for research, teaching, and private study purposes. Any substantial or systematicreproduction, redistribution, reselling, loan, sub-licensing, systematic supply, or distribution in any form toanyone is expressly forbidden.

The publisher does not give any warranty express or implied or make any representation that the contentswill be complete or accurate or up to date. The accuracy of any instructions, formulae, and drug doses shouldbe independently verified with primary sources. The publisher shall not be liable for any loss, actions, claims,proceedings, demand, or costs or damages whatsoever or howsoever caused arising directly or indirectly inconnection with or arising out of the use of this material.

http://www.tandfonline.com/loi/tejp20http://dx.doi.org/10.1080/09670260110001735478http://www.tandfonline.com/page/terms-and-conditions

Eur. J. Phycol. (2001), 36 : 321–340. Printed in the United Kingdom 321

Six new Actinella (Bacillariophyta) species from Papua New

Guinea, Australia and New Zealand: further evidence for

widespread diatom endemism in the Australasian region

KOEN SABBE1, KOENRAAD VANHOUTTE1, REX L. LOWE2,

ELIZABETH A. BERGEY3, BARRY J. F. BIGGS3, STEVE FRANCOEUR4,

DOMINIC HODGSON5 AND WIM VYVERMAN1

"Department of Biology, Laboratory of Protistology & Aquatic Ecology, University of Gent, K. L. Ledeganckstraat 35,

9000 Gent, Belgium

#Department of Biological Sciences, Bowling Green State University, Bowling Green, OH 43403, USA

$National Institute of Water & Atmospheric Research Ltd, Kyle Street, Riccarton, Christchurch, PO Box 8602, New Zealand

%Biological Sciences Department, University of Alabama, Box 870206, A-122 Bevill, Tuscaloosa, AL 35487-0206, USA

&British Antarctic Survey, High Cross, Madingley Road, Cambridge CB3 OET, UK

(Received 6 August 2000; accepted 20 March 2001)

Examination of sediment samples from oligo-and dystrophic ponds, lakes and streams in Papua New Guinea, Australia and

New Zealand revealed a hitherto unknown diversity of the diatom genus Actinella Lewis. Six new species are proposed, viz.

Actinella aotearoaia sp. nov., A. giluwensis sp. nov., A indistincta sp. nov., A. muylaertii sp. nov., A. parva sp. nov. and A.

pulchella sp. nov. All species are heteropolar, both in girdle and valve view. Novel information on the genus Actinella

includes the observations of two ribbon-shaped, valve-appressed plastids in A. aotearoaia and A. pulchella, and the presence

of long mucilage stalks in A. aotearoaia. It is argued that, despite recent proposals to reduce the genera Actinella and

Desmogonium Ehrenberg to the rank of subgenera of Eunotia, they should be kept separate until the taxonomic significance

of their distinctive morphological features (such as heteropolarity) is fully assessed. The new species appear to be endemic

to Australasia and have distinct biogeographies within this region. Except for A. aotearoaia, all species are present in

Tasmania; A. indistincta and A. pulchella have also been found in New Zealand (Stewart Island). A. aotearoaia is common

in several localities in New Zealand but was also found near Sydney on the Australian mainland. Actinella giluwensis has

only been observed in material from Papua New Guinea. The record of A. punctata for the latter country constitutes the

first confirmed record for this species outside North America and Europe. The discovery of the new Actinella species again

confirms the importance of the Australasian region as a major centre of microalgal biodiversity and endemism.

Key words : Actinella, Australia, Bacillariophyta, biogeography, endemism, morphology, New Zealand, Papua New Guinea,

taxonomy

Introduction

The subclass Eunotiophycidae, belonging to the

raphid pennate diatoms (Bacillariophyceae), is

characterized by the structure of the raphe, which is

simple and not fully integrated in the valve pattern

centre, and the presence of rimoportulae in most

genera (Round et al., 1990; Vyverman et al., 1998).

It currently comprises six genera: Desmogonium

Ehrenberg, Eunophora Vyverman, Sabbe & Mann,

Eunotia Ehrenberg, Peronia de Bre!bisson & Arnottex Kitton and Semiorbis Patrick. Actinella differs

Correspondence to: Koen Sabbe. Tel. 32 (0) 92645069. Fax:32 (0) 92645334. e-mail : Koen.Sabbe!rug.ac.be

from Desmogonium, Eunophora, Eunotia and

Semiorbis in being asymmetrical about the median

transapical plane, and from Peronia in the marginal,

not subcentral, position of the raphe.

The genusActinellawas describedbyLewis (1863)

from a shallow, spring-fed pond in New Hampshire

(USA). Twenty-nine species have hitherto been

described (Table 1), most of which are found in acid

waters (Round et al., 1990). The main centres of

diversity are tropical South America (12 species)

and Africa (11 species), while from the Northern

Hemisphere (North America and Europe) only four

species are known. To date, only two species have

been reported from Australasia, viz. A. tasmaniensis

from Tasmania (Hustedt, 1952) and A. modesta

from New Caledonia (Moser et al., 1998).

Dow

nloa

ded

by [

193.

191.

134.

1] a

t 23:

52 1

6 Ja

nuar

y 20

12

322

New

Actin

ellasp

p.fro

mA

ustra

lasia

Table 1. Actinella species list. Under Biogeography only recently confirmed or properly illustrated records are listed. The reference list is not exhaustive

Taxon Biogeography References

Type locality Europe

A. fontellii Woodhead & Tweed Europe (Sweden) Fontell (1917), Woodhead & Tweed (1957)

A. karelica Mo$ lder Europe (Scandinavia) Mo$ lder (1951)A. pliocenica He! ribaud & M. Peragallo Europe (France) He! ribaud (1902)

Type locality North America

A. punctata Lewis North America, Europe (Scandinavia), Papua New Guinea Kociolek et al. (1997), Lewis (1863), this study

Type locality South America

A. brasiliensis Grunow in Van Heurck South America (e.g. Brazil, Guyana, Ecuador, Surinam), Japan Metzeltin & Lange-Bertalot (1998), Okuno (1964), Van Heurck (1881)a

A. mirabilis (Eulenstein?) Grunow in Van Heurck South America (e.g., Brazil, Ecuador) De Oliveira & Steinitz-Kannan (1992), Uherkovich (1986), Van Heurck (1881)

A. guinanensis Grunow in Van Heurck South America (e.g., Brazil, Guyana, Ecuador) Metzeltin & Lange-Bertalot (1998), Van Heurck (1881)

A. scala Brun South America (Barbados) Brun (1896)

A. peronioides Hustedt South America (Brazil, Venezuela) Hustedt (1952), Metzeltin & Lange-Bertalot (1998)

A. eunotioides Hustedt South America (Venezuela) Hustedt (1952), Metzeltin & Lange-Bertalot (1998)

A. robusta Hustedt South America (Brazil, Ecuador) Hustedt (1952), Metzeltin & Lange-Bertalot (1998)

A. gessneri Hustedt South America (Brazil) Hustedt (1965)

A. siolii Hustedt South America (Brazil, Venezuela) Hustedt (1965), Metzeltin & Lange-Bertalot (1998)

A. leontopithecus-rosalia da Costa South America (Brazil) da Costa (1995)

A. pararobusta Metzeltin & Lange-Bertalot South America (Brazil) Metzeltin & Lange-Bertalot (1998)

A. pseudohantzschia Metzeltin & Lange-Bertalot South America (Brazil, Guyana) Metzeltin & Lange-Bertalot (1998)

Type locality Africa

A. cholnokii Woodhead & Tweed Africa (South Africa) Cholnoky (1954a), Woodhead & Tweed (1957)

A. raytonensis (Cholnoky) Woodhead & Tweed Africa (South Africa) Cholnoky (1955), Woodhead & Tweed (1957)

A. theronii (Cholnoky) Woodhead & Tweed Africa (South Africa) Cholnoky (1954b), Woodhead & Tweed (1957)

A. africana Woodhead & Tweed Africa (Sierra Leone) Woodhead & Tweed (1957)

A. spathulifera Woodhead & Tweed Africa (Sierra Leone) Woodhead & Tweed (1957)

A. australis (Manguin) Kociolek, Rhode & Williams Africa (Madagascar) Kociolek et al. (1997)

A. manguinii Kociolek, Rhode & Williams Africa (Madagascar) Kociolek et al. (1997)

A. candelabrum (Manguin) Kociolek & Rhode Africa (Madagascar) Bourelly & Manguin (1949), Kociolek & Rhode (1998)

A. madagascariensis (Manguin) Kociolek & Rhode Africa (Madagascar) Bourelly & Manguin (1949), Kociolek & Rhode (1998)

A. bourrellyi (Manguin) Kociolek & Rhode Africa (Madagascar) Bourelly & Manguin (1949), Kociolek & Rhode (1998)

A. reviersii (Manguin) Kociolek & Rhode Africa (Madagascar) Bourelly & Manguin (1949), Kociolek & Rhode (1998)

Type locality Australasia

A. tasmaniensis Hustedt Australia (Tasmania) Hustedt (1952), Vyverman et al. (1995), this study

A. modesta Moser, Lange-Bertalot & Metzeltin New Caledonia Moser et al. (1998)

A. aotearoaia Lowe, Biggs & Francoeur New Zealand This study

A. giluwensis Sabbe & Vyverman Papua New Guinea This study

A. indistincta Vyverman & Bergey Australia (Tasmania), New Zealand This study

A. muylaertii Sabbe & Vyverman Australia (Tasmania) This study

A. parva Vanhoutte & Sabbe Australia (Tasmania), New Zealand This study

A. pulchella Sabbe & Hodgson Australia (Tasmania), New Zealand This study

A. comperei Sabbe, Vanhoutte & Vyverman Australia (Tasmania) Sabbe et al. (2000)

a See text for further references and remarks on this species.

Dow

nloa

ded

by [

193.

191.

134.

1] a

t 23:

52 1

6 Ja

nuar

y 20

12

K. Sabbe et al. 323

The present study forms part of a taxonomic and

biogeographic investigation of the diatom floras of

three Australasian countries (Papua New Guinea,

Australia and New Zealand) which has already led

to the discovery of several endemic diatom taxa,

including the genus Eunophora and five new fresh-

water Biremis species (Vyverman, 1988; Vyverman

et al., 1997, 1998). An investigation of the benthic

diatom communities of predominantly dystrophic

subalpine lakes, tarns and streams in the above-

mentioned countries revealed the presence of six

new species belonging to the genus Actinella ; a

seventh new species is described elsewhere (Sabbe

et al., 2000). Below, we present a detailed morpho-

logical description of each species based on light

and scanning electron microscopy. The taxonomic

status of Actinella and other genera belonging to the

Eunotiophycidae as well as the biogeography and

ecology of the new Actinella species are described

and discussed.

Materials and methods

Samples were scraped from diverse littoral substrata(surface sediments, rocks and submerged macroalgae andmacrophytes) of dystrophic and (ultra-)oligotrophiclakes, ponds and streams in Papua New Guinea,Australia (New South Wales, Tasmania) and NewZealand. Detailed information on sampling sites anddates is given in Table 2. In the Tasmanian highlands,where most studied materials come from, two limno-logical regions are recognized, namely a western and aneastern province. Lakes in these two provinces differ inoptical and chemical properties (caused by edaphic,climatic, geological and vegetational differences). West-ern lakes are strongly humic, moderately to highlydystrophic and have low pH and alkalinity, while easternlakes are less acidic, (ultra-)oligotrophic and have higheralkalinity. In between these two regions lies a corridorzone where intermediate-type lakes can be found (hence-forth called corridor lakes ; Tyler, 1992; Vyverman et al.,1996). The distribution of each Actinella species found inTasmania is described in relation to this limnologicalgradient. More information on the limnological featuresof the lakes listed can be found in Vyverman et al. (1995,1996, 1997).

Samples were fixed with 3–4% formaldehyde.Specimens of Actinella brasiliensis were investigated onAWH (Van Heurck Collection, Antwerp, Belgium) slidesVIII 37 B 6 (Weissflog collection 553, Surinam) and (IX61 A 4 (Donkin 2523, Iganape, Surinam). When possible,observations were made on live material (Figs 1, 2) inorder to study plastid structure and life form.

Subsamples were digested with concentrated acids(H

#SO

%or a H

#SO

%}HNO

$mixture: Patrick & Reimer,

1966) and washed several times with distilled water. Forlight microscopy (LM), part of the samples were driedonto glass coverslips, mounted in Naphrax and studiedusing a Zeiss Axioplan 2 equipped with differentialinterference contrast optics (DIC), a Leitz Ortholux(DIC) or an Olympus BH2 (bright field optics). Some T

able

2.L

istofsa

mpling

site

sand

date

s,habitatty

pe

and

refe

rence

tost

udie

spro

vid

ing

det

ailed

info

rmation

on

morp

hom

etric

and

wate

rch

emistr

ydata

.N

ote

thatfo

rth

eA

ust

ralian

main

land

and

the

New

Zea

land

loca

lities

no

such

data

are

available

Loca

lity

Habitatty

pe

Date

Wate

rch

emistr

y

Aust

ralia

Tasm

ania

Dyst

rophic

tooligotr

ophic

,hum

ichig

hla

nd

lakes

and

tarn

sbet

wee

n490

and

1202

maltitude

Feb

.–D

ec.1994,F

eb.1995

Vyver

man

etal.

(1996)

RoyalN

ationalPark

,Sydney

,N

ewSouth

Wale

sA

cidic

cree

k(K

angaro

oC

reek

)dra

inin

gSydney

sandst

one

at³

50

maltitude

July

1997

–

New

Zea

land

Ariel

sT

arn

,H

arm

an

Pass

,A

rthur’s

Range

National

Park

,South

Isla

nd

Tw

oalp

ine

aci

d-w

ate

rta

rns

at1320

maltitude

Marc

h1997

–

Outlet

ofsm

all

tarn

close

totw

ota

rns

(cf.

above)

Dec

.1998

–

O’C

onner

Cre

ek(a

tN

XH

iway

6),

Om

oer

aSaddle

,

Wes

tland,South

Isla

nd

‘Bla

ckw

ate

r’st

ream

at400

maltitude

Jan.1992,Ja

n.1997

pH

¯5,co

nduct

ivity¯

10

µS

cm−"

Table

Hill,

Ste

wart

Isla

nd

Aci

dic

tarn

sand

stre

am

sin

the

pen

alp

ine

zone

ofnative

gra

sses

at380

maltitude

Oct

.1997

pH

!7

Papua

New

Guin

eaM

ountG

iluw

e,South

ern

Hig

hla

nds

Pro

vin

ceSm

all

alp

ine

aci

dic

lake

at3540

maltitude

Aug.–

Oct

.1987

pH

¯6±2

,co

nduct

ivity¯

15

µS

cm−"

Vyver

man

(1991)

Dow

nloa

ded

by [

193.

191.

134.

1] a

t 23:

52 1

6 Ja

nuar

y 20

12

324New Actinella spp. from Australasia

coverslips were attached to aluminium specimen stubswith double-sided tape and silver paint and sputter-coated with an Au}Pd alloy for examination withscanning electron microscopy (SEM). Sample materialwas also directly air-dried onto specimen stubs andsputter-coated. SEM was performed with a Jeol JSM-840operated at 15 kV or a Hitachi S-2700. In order toobserve soft parts of diatoms (stalks and pads), portionsof some samples were mounted on SEM stubs prior toacid digestion. Formaldehyde was removed over 3 daysemploying a series of distilled water rinses. Samples werethen fixed with glutaraldehyde (25% final concentration)overnight, then post-fixed with OsO

%(0±2% final con-

centration) for 2 h. Excess fixative was removed using aseries of distilled water rinses. Samples were thendehydrated with an ascending series of ethanol rinses(25%, 40%, 60%, 80%, 95%, 100% ¬3), then im-mersed in hexamethyldisilazane for 5 min (Nation, 1983).Following immersion, specimens were mounted, coatedand observed as above.

Frustule dimensions (length (L), width (W) and striadensity (S)) were determined on 20 valves of each species,unless stated otherwise. For each dimension theminimumand maximum values are given, whilst the average valueand the standard deviation are given in parentheses.Terminology used in the description of the structures ofthe siliceous cell wall is based on Hendey (1964: valveoutlines and structural types), Anonymous (1975), Rosset al. (1979), Cox & Ross (1980) and Round et al. (1990:cingulum and raphe structures).

Results

Actinella aotearoaia R. L. Lowe, B. J. F. Biggs &

F. Francoeur, sp. nov.

Figs 2–20

Cellulae clavatae aspectu cincturae, 9±0–31±2(20±1³6±3) µm longae, substrato affixae per pen-dunculum mucilaginum longum. Chromatophora

elongata 2 ad valvas appressa. Valvae valde clavatae

et leviter semi-arcuatae, 2±5–3±5 (2±5³0±4) µm lataein media parte ; specimina grandia distincte solei-

formia. Capitus-polus 3±3–6±2 (4±5³0±7) µm latus,rotundatus, valde tumescens in latere ventrali et

dorsali, valde asymmetricus quoad axem apicalem.

Basis 1±0–2±2 (1±4³0±3) µm lata, non tumescens.Striae 16–20 (18±3³1±4) in 10 µm, parallelae, capito-polo versus valde radiatae. Areolae circulares volis

occlusae. Spinulae marginales nullae. Sternum

indistinctum. Raphe brevis magnopere in limbo

valvarum sita ; apices distales earum in facie val-

varum flexi. Helictoglossae parvae, sed plerumque

in latere ventrali valvae positae semper manifestae.

Rimoportula una, ad laterem ventralem basis vel

capiti-poli posita, in transitione faciei valvarum

limbo; in frustulo completo rimoportulae valvarum

semper ad polos opposites positae. Cingulum ex 4

copulis apertis curvatis porosis constans.

Cells clavate in girdle view, 9±0–31±2(20±1³6±3) µm long, attached to the substratum via

Figs 1, 2. Light microscopy of living Actinella species. Fig.

1. A. pulchella. Arrowheads show small round structures

(possibly pyrenoids). Fig. 2. A. aotearoaia. Scale bar

represents 10 µm.

a long mucilaginous stalk. Two elongate, valve-

appressed plastids. Valves strongly clavate and

slightly semi-arcuate, 2±5–3±5 (2±5³0.4) µm wide atmidpoint ; larger specimens distinctly sole-shaped.

Headpole 3±3–6±2 (4±5³0±7) µm wide, rounded,strongly bulged on the dorsal and ventral side, and

strongly asymmetrical about the apical plane. Foot-

pole 1±0–2±2 (1±4³0±3) µm wide, not tumescent.Striae 16–20 (18±3³1±4) in 10 µm, parallel to radiateat the headpole. Areolae round, occluded by volate

vela. No marginal spines. Sternum indistinct. Raphe

short, largely situated on the valve mantle ; distal

ends bent onto the valve face. Helictoglossae small,

but usually clearly visible on the ventral side of the

valve. Rimoportula one per valve, lying on the

ventral side of the foot- or headpole on the valve

face}mantle transition; in a complete frustule, therimoportulae of the two valves always lie at opposite

poles. Cingulum composed of 4 open, strongly

curved, porous copulae.

E : This species is named for Aotearoa,

the Maori name for New Zealand, meaning ‘land of

the long white cloud’.

H : BM slide 100921, The Natural History

Museum, Department of Botany, London.

I : BRM slide Zu5}35 Friedrich Hustedt-

Dow

nloa

ded

by [

193.

191.

134.

1] a

t 23:

52 1

6 Ja

nuar

y 20

12

K. Sabbe et al. 325

Figs 3–20. Light (Figs 10–14, 16–20) and SEM (Figs 3–9, 15) micrographs of Actinella aotearoaia from different localities :

Figs 3, 8, 12, 14, 16–17, 20, Ariels Tarn, New Zealand (holotype population) ; Figs 4–7, 9, O’Conner Creek, New Zealand;

Figs 10, 11, Kangaroo Creek, Australia ; Figs 13, 15, unnamed tarn, Stewart Island, New Zealand. Fig. 3. External valve

view showing external rimoportula opening (arrow). Fig. 4. External girdle view of two cells on a bifurcating stalk. Fig. 5.

Oblique external view. Note the two raphe branches (R) and the opening of the rimoportula (L). Fig. 6. Internal view of the

headpole showing the helictoglossa (H) and the rimoportula (L). Fig. 7. External view of the footpole with areolar

occlusions (P). Fig. 8. External oblique view showing curved, open copulae. Fig. 9. Rimoportula (L) in internal footpole

view. Fig. 10. Possible initial valve. Figs 11–14, 16, 17. Valve views. Arrowheads in Figs 14 and 17 indicate striae that are

out of phase and hence the position of the sternum. Fig. 15. External valve view. Figs 18–20. Girdle views. Note the distinct

raphe branches and the copulae with scattered areolae. Scale bars represent 10 µm (Figs 3, 4, 10–14, 16–20), 5 µm (Fig. 5)

and 1 µm (Figs 6–9, 15) ; scale bar for Figs 14, 16 and 17 is shown in Fig. 12.

Arbeitsplatz fu$ r Diatomeenkunde, Bremerhaven;CAS slide 220053, California Academy of Sciences,

San Francisco; slide KS0101, the Herbarium, Uni-

versity of Gent (GENT).

T : Ariels Tarn (171°25«0§E, 42°56«26§S),Harman Pass (Arthur’s Range National Park,

South Island, New Zealand), surface sediment

samples.

Five different populations of this species have been

studied.Morphometric analyses revealed significant

differences in headpole width and stria density

between some of these populations (unpublished

data, but compare e.g. Fig. 13, which depicts a

narrow, more finely striated valve from Stewart

Island, with the valves from Ariels Tarn in Figs 12,

14, 16 and 17). As the taxonomic significance of this

phenomenon is not yet clear (i.e. whether this

variability has a genetic basis or whether it merely

reflects differing environmental conditions or

different stages in the cell size reduction cycle), we

have based the protologue (and the description

below) of A. aotearoaia on the populations from

Ariels tarn.

Living cells of A. aotearoaia have two ribbon-like,

sometimes curled plastics, one under each valve

(Fig. 2). A small droplet is present just above the

Dow

nloa

ded

by [

193.

191.

134.

1] a

t 23:

52 1

6 Ja

nuar

y 20

12


centre of the cell. The cells were observed at the ends

of relatively long mucilage stalks that may bifurcate

following cell division (Figs 2, 4). Cells are strongly

clavate in girdle view (Figs 18–20) ; in valve view,

they are often distinctly sole-shaped. However, in

valves from Stewart Island (Figs 13, 15) and

Kangaroo Creek (Figs 10, 11) this was much less

pronounced. A large valve from Kangaroo Creek

(Fig. 10; 41±5 µm long) which has a slight centralinflation probably represents an initial valve. A.

aotearoaia is the only species described in this paper

which had intact areolar occlusions. Externally, the

volate vela only partially occlude the areolae, which

results in curved openings (Fig. 7). Internally, the

areolae appear as simple pores (Fig. 9). The sternum

is very narrow and usually only visible when some

striae are out of phase (Figs 14, 17). The short raphe

branches are largely situated on the mantle and thus

only visible in girdle view (Figs 18–20) ; they are

often irregularly curved (Figs 3, 5). There are two

sessile rimoportulae per frustule, lying at diagonally

opposite poles. The cingulum is composed of 4

open, curved copulae. Apart from one longitudinal

row of puncta on the advalvar side of each copula

(Figs 5, 8), numerous large puncta lie randomly

scattered on the copulae, which gives this species a

distinctive appearance in girdle view (Figs 18–20).

D : Actinella aotearoaia is present, and

often dominant (e.g. up to 35% in the epiphyton of

O’Conner Creek, Westland) in several epiphytic (on

Batrachospermum Roth, Stigonema Agardh and

mosses) and sediment samples from the South

Island of New Zealand and Stewart Island. It is also

present in samples from Kangaroo Creek (Royal

National Park, Sydney) on the Australian main-

land. The specimen illustrated as Actinella

brasiliensis in Foged (1979, pl. XII, fig. 12) from the

North Island of New Zealand probably also belongs

to A. aotearoaia. To date, it has not been observed

in the Tasmanian material.

Actinella giluwensis K. Sabbe & W. Vyverman, sp.

nov.

Figs 21–30

Cellulae leviter clavatae aspectu cincturae, 141±2–176±7 (150±8³11±8) µm longae (n¯ 6). Structurachromatophororum incognita. Valvae clavatae,

leviter semi-arcuatae, margine ventrali concava et

margine dorsali convexa, 8±6–11±2 (9±8³0±8) µmlatae in media parte. Capitus-polus 16±8–20±0(18±3³1±4) µm latus, tumescens in latere ventrali etdorsali, sub-rostratus. Projectura apicalis posita in

centro capiti-poli. Basis 10±0–11±9 (10±7³0±8) µmlata, leviter tumescens, rotundata. Striae punctatae,

12–16 (14±2³1±2) in 10 µm, ad centrum parallelae,apices versus leviter radiatae. Areolae parvae,

circulares ; structura velorum incognita (possibiliter

erosa). Margo valvae spinulis simplicibus praedita.

Sternum angustum et indistinctum. Raphe brevis

magnopere in limbo valvarum sita ; apices distales

earum in facie valvarum flexi. Helictoglossae

distinctae, in latere ventrali valvae positae semper

manifestae. Rimoportulae duae, in limbo ad laterem

ventralembasis et in parte apicali capiti-poli positae.

Cingulum ex 4 copulis apertis ligulatis, seriebus

aliquot per copulam.

Cells slightly clavate in girdle view, 141±2–176±7(150±8³11±8) µm long (n¯ 6). Plastid structureunknown. Valves clavate, slightly semi-arcuate,

with ventral margin concave and dorsal margin

convex, 8±6–11±2 (9±8³0±8) µm wide at midpoint.Headpole 16±8–20±0 (18±3³1±4) µm wide, bulged onthe dorsal and ventral side, sub-rostrate. Footpole

10±0–11±9 (10±7³0±8) µm wide, slightly tumescent,rounded. Apical projection in the centre of the

headpole. Striae punctate, 12–16 (14±2³1±2) in10 µm, parallel in the centre to slightly radiate at the

poles. Areolae small, round; velum structure un-

known (possibly eroded). Small, simple spines are

present along the valve margin. Sternum narrow

and indistinct. Raphe short, largely situated on the

valve mantle ; distal ends bent onto the valve face.

Helictoglossae distinct, clearly visible on the ventral

side of the valve. Rimoportulae two per valve, on

the mantle on the ventral side of the footpole and in

the apical part of the headpole. Cingulum composed

of 4 open, ligulate copulae, with several rows of

poroids per copula.

E : This species is named for Mount

Giluwe, situated in the Southern Highlands Prov-

ince of Papua New Guinea.



I : BRM slide Zu5}36 Friedrich Hustedt-Arbeitsplatz fu$ r Diatomeenkunde, Bremerhaven;CAS slide 220054, California Academy of Sciences.

San Francisco; slide KS0102, The Herbarium,

University of Gent (GENT).

T : Outlet of unnamed lake (143°55«40§E, 06°03«08§S), Mount Giluwe (SouthernHighlands Province, Papua New Guinea, altitude

3540 m).

Only a few valves and complete frustules of this

species were observed. The areolae are pore-like ; no

occlusions could be observed (Figs 21, 22). The

raphe is largely situated on the valve mantle (Figs

21, 22, 26) although the terminal fissures can be seen

to extend onto the valve face in Figs 23, 24 and 30.

Spines are present along the whole valve face margin

(Figs 22–24, 27–30). The sternum is very narrow

Dow

nloa

ded

by [

193.

191.

134.

1] a

t 23:

52 1

6 Ja

nuar

y 20

12

K. Sabbe et al. 327

Figs 21–30. Light (Figs 23–25, 27–30) and SEM (Figs 21, 22, 26) micrographs of Actinella giluwensis from an unnamed

lake, Mount Giluwe, Papua New Guinea (holotype population). Fig. 21. Internal view of the headpole showing the

helictoglossa and rimoportula ; the sternum is arrowed. Fig. 22. Oblique view of footpole. Note the rimoportula

(arrowhead). Figs 23, 24. Valve views of headpole and complete valve. Note the distinct helictoglossae and the sternum

(arrowhead) in Fig. 23. Fig. 25. Girdle view. Fig. 26. Internal view of the headpole of the same valve as in Fig. 22. The

small rimoportula in the valve apex is arrowed. Fig. 27. Girdle view of headpole showing the marginal spines and the

puncta on the copulae. Figs 28, 29. Girdle view of the same footpole at different foci. In Fig. 28 the two rimoportulae,

situated between the valve apex and the relatively large helictoglossae, are arrowed. Fig. 30. Valve view of headpole. Scale

bars represent : 10 µm (Figs 23–25, 27–30) and 1 µm (Figs 21, 22, 26). Scale bar for Fig. 29 is shown in Fig. 28.

and can mainly be seen because striae are out of

phase on either side of it (Figs 21, 23). The

rimoportulae are sessile and can only be observed in

LM when the cells are viewed in girdle view (Fig. 28)

as they are relatively small and largely situated on

the valve mantle (Figs 21, 22, 26). The distinct

helictoglossae (Figs 21, 22, 26) are conspicuous in

both valve (Fig. 24) and girdle view (Fig. 28). The

copulae are only slightly curved near the apices. As

in A. aotearoaia there is one advalvar longitudinal

row of puncta on each copula (not shown); on the

rest of the copulae a few irregular rows of puncta are

present (Fig. 27).

This large species is reminiscent of Actinella

guinanensis (cf. Metzeltin & Lange-Bertalot, 1998)

from which it mainly differs in the medial (and not

dorsal) position of the apical point, and valve shape

(less bent, footpole only slightly tumescent).

Dow

nloa

ded

by [

193.

191.

134.

1] a

t 23:

52 1

6 Ja

nuar

y 20

12


Figs 31–44. SEM (Figs 31–35, 44) and light (Figs 36–43) micrographs of Actinella indistincta from Oberon Tarn (Tasmania,

holotype population). Fig. 31. External girdle view of complete frustule. Note the advalvar rows of puncta on the copulae

(arrowheads) and the additional row of puncta in the middle of the copulae. Fig. 32. Detail of headpole of the same

frustule as in Fig. 31 showing the curved copulae. Arrowhead shows the external rimoportula opening. Fig. 33. External

view of footpole. Note the external rimoportula opening (arrowhead). Fig. 34. Detail of the footpole of the same frustule as

in Fig. 31. The rimoportula opening is arrowed. Fig. 35. Headpole of frustule shown in Fig. 44. The small rimoportula is

arrowed. Figs 36–41. Valve views. Figs 42–43. Girdle views. Fig. 44. Internal valve view. Arrowhead indicates the

rimoportula in the headpole. Scale bars represent : 10 µm (Figs 31, 36–44), 5 µm (Figs 33, 34) and 1 µm (Figs 32, 35). Scale

bar for Figs 37–43 is shown in Fig. 36.

Actinella giluwensis was previously illustrated as

Actinella punctata (partim) in Vyverman (1991, p1.

9, figs 2–5, 7, p1. 169, fig. D, p1. 170, fig. A).

D : This species was rare in the

epiphyton of oligotrophic highland tarns at con-

ductivities of 11–66 µS cm−" and pH 6–7, where it

was found together with Actinella punctata (see

below).

Actinella indistincta W. Vyverman & E. Bergey, sp.

nov.

Figs 31–44

Cellulae leviter clavatae aspectu cincturae, 15±0–36±4

Dow

nloa

ded

by [

193.

191.

134.

1] a

t 23:

52 1

6 Ja

nuar

y 20

12

K. Sabbe et al. 329

(23±8³5±8) µm longae (n¯ 12). Structura chro-matophororum incognita. Valvae leviter semi-

arcuatae et heteropolares, margine ventrali plus

minusve concave et margine dorsali convexa,

1±2–2±2 (1±6³0±3) µm latae in media parte. Capitus-polus 1±0–1±5 (1±2³0±1) µm latus, non tumescens.Basis 0±9–1±2 (1±1³0±1) µm lata, non tumescens.Striae per microscopium usitatum non facile de-

tectae, 26–30 (27±2³1±1) in 10 µm, ad centrumparallelae, apices versus leviter radiatae. Areolae

parvae, circulares ; structura velorum incognita

(possibiliter erosa). Sternum angustum et indis-

tinctum. Raphe brevis magnopere in limbo val-

varum sita ; apices distales earum in facie valvarum

flexi. Helictoglossae distinctae, in latere ventrali

valvae positae semper manifestae. Rimoportula

una, ad laterem ventralem basis vel capiti-poli

posita, in transitione faciei valvarum limbo; in

frustulo completo rimoportulae valvarum semper

ad polos oppositos positae. Cingulum probabiliter

ex 4 copulis apertis ligulatis porosis constans.

Cells slightly clavate in girdle view, 15–36±4(23±8³5±8) µm long (n¯ 12). Plastid structure un-known. Valves slightly semi-arcuate and hetero-

polar, with ventral margin more or less concave and

dorsal margin convex, 1±2–2±2 (1±6³0±3) µm wide atmidpoint. Headpole 1±0–1±5 (1±2³0±1) µm wide, nottumescent. Footpole 0±9–1±2 (1±1³0±1) µm wide,not tumescent. Striae often difficult to resolve with

the light microscope, 26–30 (27±2³1±1) in 10 µm,parallel in the centre to slightly radiate at the poles.

Velum structure unknown (possibly eroded). Ster-

num narrow and indistinct. Raphe short, largely

situated on the valve mantle ; distal ends bent onto

the valve face. Helictoglossae distinct, clearly visible

on the ventral side of the valve. Rimoportula one

per valve, lying on the ventral side of the foot- or

headpole on the valve face}mantle transition; in acomplete frustule, the rimoportulae of the two

valves always lie at opposite poles. Cingulum

probably composed of 4 open, ligulate, porous

copulae.



I : BRM slide Zu5}37 Friedrich Hustedt-Arbeitsplatz fu$ r Diatomeenkunde, Bremerhaven;CAS slide 220055, California Academy of Sciences,



T : Oberon Tarn, Tasmania, Australia.

Actinella indistincta is only slightly heteropolar,

both in valve (Figs 36–41) and girdle view (Figs

42–43). It can only be confused with A. parva (cf.

below), which has a similar size range but a

significantly lower stria density. The sternum is only

just visible in SEM (Fig. 32). The areolae are pore-

like ; no occlusions could be observed. The rimo-

portulae are small and sessile. There is only one

rimoportula per valve; within a frustule, they are

diagonally opposed (compare Figs 31, 32, 34). Each

copula has one advalvar row of puncta, and an

additional row in the middle of the valve (Figs 31,

32, 34).

D : Actinella indistincta was found in

one western (Oberon Tarn) and one corridor lake

(Twisted L.) in Tasmania , and in an unnamed tarn

on Stewart Island (New Zealand).

Actinella muylaertii K. Sabbe & W. Vyverman, sp.

nov.

Figs 45–61

Cellulae clavatae aspectu cincturae, 11±0–28±0(20±7³3±5) µm longae. Structura chromato-phororum incognita. Valvae valde clavatae, 1±5–2±5(2±2³0±3) µm latae in media parte, leviter semi-arcuatae, asymmetricae quoad axem apicalem.

Capitus-polus 5±0–7±0 (6±3³0±5) µm latus, valdetumescens in latere ventrali et dorsali, rostratus ad

capitatus. Basis 0±9–1±7 (1±2³0±2) µm lata, nontumescens. Striae 16–21 (18±9³1±2) in 10 µm,parallelae, capito-polo versus valde radiatae.

Areolae parvae, circulares ; structura velorum

incognita (possibiliter erosa). Spinulae marginales

nullae, sed margo valvae nonnumquam crista

angusta praedita. Sternum angustum. Raphe brevis



parvae, sed plerumque in latere ventrali valvae

positae semper manifestae. Rimoportula una, ad

laterem ventralem basis posita, in transitione faciei

valvarum limbo. Cingulum ex 4 copulis apertis

curvatis porosis constans.

Cells clavate in girdle view, 11±0–28±0(20±7³3±5) µm long. Plastid structure unknown.Valves strongly clavate, 1±5–2±5 (2±2³0±3) µm wideat midpoint, slightly semi-arcuate, asymmetrical

about the apical plane. Headpole 5±0–7±0(6±3³0±5) µm wide, strongly bulged on the dorsaland ventral side, rostrate to capitate. Footpole

0±9–1±7 (1±2³0±2) µm wide, not tumescent. Striae16–21 (18±9³1±2) in 10 µm, parallel to stronglyradiate at the headpole. Velum structure unknown

(possibly eroded). No marginal spines, but in some

specimens a narrow ridge is present along the valve

margin. Sternum narrow. Raphe short, largely

situated on the valve mantle ; distal ends bent onto

the valve face. Helictoglossae small, but usually

clearly visible on the ventral side of the valve.

Rimoportula one per valve, lying on the ventral side

Dow

nloa

ded

by [

193.

191.

134.

1] a

t 23:

52 1

6 Ja

nuar

y 20

12


Figs 45–61. SEM (Figs 45–54) and light (Figs 55–61) micrographs of Actinella muylaertii from Lonely Tarn (Tasmania,

holotype population, Figs 45–47, 49, 51–61) and Reservoir 2 (Tasmania, Figs 48, 50). Fig. 45. External valvar view of the

headpole. Fig. 46. External valvar view of the footpole. The rimoportula opening is arrowed. Fig. 47. External ventral view

of a complete frustule. The opposed rimoportula openings are arrowed. Fig. 48. Internal valvar view showing the

rimoportula at the footpole (arrowhead). Figs 49, 50. Internal views of the headpole. Note the short raphe branch in Fig.

49. Fig. 51. External dorsal view of a complete frustule. Fig. 52. Girdle view of the headpoles and cingulum of a complete

frustule. Note the strongly curved, porous copulae and the siliceous marginal ridge. Fig. 53. External ventral view of a

complete frustule. Note the marginal ridge. Fig. 54. External valvar view of a headpole. Fig. 55. Girdle view of recently

divided cells. Fig. 56. Girdle view of a complete frustule. Note that the apex at the headpole is shown at a different focus.

Figs 57–61. Valve views showing range in size and shape. Scale bars represent : 10 µm (Figs 55–61) and 1 µm (Figs 45–54).

Scale bar for Figs 57–60 is shown in Fig. 61.

of the footpole on the valve face}mantle transition.Cingulum composed of 4 open, curved, porous

copulae.

E : This species is dedicated to our col-

league Koenraad Muylaert who provided us with

some of the material examined.



Dow

nloa

ded

by [

193.

191.

134.

1] a

t 23:

52 1

6 Ja

nuar

y 20

12

K. Sabbe et al. 331




T : Lonely Tarn, Tasmania, Australia.

A. muylaertii can easily be recognized in LM by its

pronounced clavate valve shape with medial apical

point. The valve is strongly asymmetrical about the

apical plane not only because of its semi-arcuate

shape, but also because the ventral bulge of the

headpole is more distally placed than the dorsal

bulge. Strongly heteropolar Actinella species were

also reported (as A. brasiliensis) by Carter & Denny

(1987, p1. 1, fig. 5) from Sierra Leone but their

illustration shows a specimen with a dorsal and

ventral apex. The true identity of their specimens

needs to be investigated. The sternum is narrow but

rather distinct (even in LM, Figs 57–61) in com-

parison with the other newly described Actinella

species. Spines were not observed but a siliceous

ridge was present in some specimens (Figs 52–54).

The helictoglossae are relatively small (again in

comparison with the other species described; Figs

48–50) ; the raphe is sometimes very short (Fig. 49).

Small, sessile rimoportulae were hitherto only

observed in the footpole (Figs 46–48) ; within a

frustule, the rimoportulae of the two valves thus lie

at the same pole (Fig. 47). The copulae are strongly

curved near the headpole. They have, in addition to

one distinct advalvar row of puncta, several other

rows of puncta (Figs 47, 51–53).

Actinella muylaertii was previously illustrated as

Actinella sp. 1 (partim) in Vyverman et al. (1995, pl.

21, fig. 12).

D : Actinella muylaertii was found in

four Tasmanian lakes (the corridor lakes Reservoir

1 and 2, and the western lakes L. Picone and Lonely

Tarn).

Actinella parva K. Vanhoutte & K. Sabbe, sp. nov.

Figs 62–78

Cellulae leviter clavatae aspectu cincturae, 11±0–30±6(17±5³4±6) µm longae. Structura chromato-phororum incognita. Valvae leviter semi-arcuatae

et heteropolares, margine ventrali plus minusve

concave et margine dorsali convexa, 1±5–2±3(2±0³0±2) µm latae in media parte. Capitus-polus1±0–1±6 (1±3³0±2) µm latus, non tumescens. Basis0±9–1±2 (1.0³0±1) µm lata, non tumescens. Striae19–22 (20±4³0±8) in 10 µm, ad centrum parallelae,apices versus radiatae. Areolae parvae, circulares ;

structura velorum incognita (possibiliter erosa).

Sternum angustum et indistinctum. Raphe brevis



distinctae, in latere ventrali valvae positae semper

manifestae. Rimoportula una, ad laterem ventralem

basis vel capiti-poli posita, in transitione faciei

valvarum limbo; in frustulo completo rimoportulae

valvarum semper ad polos oppositos positae.

Cingulum probabiliter ex 4 copulis apertis porosis

constans.

Cells slightly clavate in girdle view, 11±0–30±6(17±5³4±6) µm long. Plastid structure unknown.Valves slightly semi-arcuate and heteropolar, with

ventral margin concave and dorsal margin convex,

1±5–2±3 (2±0³0±2) µm wide at midpoint. Headpole1±0–1±6 (1±3³0±2) µm wide, not tumescent. Footpole0±9–1±2 (1±0³0±1) µm wide, not tumescent. Striae19–22 (20±4³0±8) in 10 µm, parallel in the centre toradiate at the poles. Areolae small, circular ; velum

structure unknown (possibly eroded). Sternum nar-

row and indistinct. Raphe short, largely situated on

the valve mantle ; distal ends bent onto the valve

face. Helictoglossae distinct, clearly visible on the

ventral side of the valve. Rimoportula one per

valve, lying on the ventral side of the foot- or

headpole on the valve face}mantle transition; in acomplete frustule, the rimoportulae of the two

valves always lie at opposite poles. Cingulum

probably composed of 4 open, porous copulae.



I : BRM slide Zu5139 Friedrich Hustedt-

Arbeitsplatz fu$ r Diatomeenkunde, Bremerhaven;CAS slide 220057, California Academy of Sciences,



T : Clarence Lagoon, Tasmania,

Australia.

This small Actinella species is rather reminiscent of

Actinella indistincta (cf. above) but has a signifi-

cantly lower stria density. A. parva is only slightly

heteropolar, both in girdle and valve view (Figs

69–78). No distinct sternum can be distinguished

(cf. Fig. 63). The sessile rimoportulae are situated

on the valve face}mantle transition (Figs 64, 67, 68).The copulae are open and slightly curved near the

apices (Figs 62, 64, 65) ; apart from one advalvar

longitudinal row of puncta, a single additional row

is present in the middle of the copula (Figs 62, 64).

Actinella parva was previously illustrated as

Actinella sp. 1 (partim) in Vyverman et al. (1995, p1.

5, figs 6, 8).

D : Actinella parva is common and

widely distributed in the western and corridor lakes

in the Tasmanian highlands but is absent from the

eastern lakes. It has not been found outside

Tasmania.

Dow

nloa

ded

by [

193.

191.

134.

1] a

t 23:

52 1

6 Ja

nuar

y 20

12


Figs 62–78. SEM (Figs 62–68, 78) and light (Figs 69–77) micrographs of Actinella parva from Clarence Lagoon (Tasmania,

holotype population, Figs 62, 64–68, 72–76), Lake Vera (Tasmania, Fig. 63), Lonely Tarn (Tasmania, Fig. 69) and Lake

Rolleston (Tasmania, Figs 70, 71). Fig 62. External girdle view showing cingulum structure and diagonally opposed

rimoportula openings (arrowed). Fig. 63. External, oblique valve view. The rimoportula opening at the headpole is

arrowed. Fig. 64. External girdle and internal valve view, showing the rimoportula at the footpole. Note the rows of puncta

on the valvocopula. Fig. 65. External valve and girdle view. Arrowhead indicates the rimoportula opening at the headpole.

Figs 66–68. Internal valve view (Fig. 68) and details of head- and footpole (Figs 66 and 67 respectively) showing the

rimoportula at the foot pole (arrowheads in Figs 67 and 68). Fig. 69. Girdle view. Figs 70–78. Valve views showing the

range in size and shape. Scale bars represent : 10 µm (Figs 65, 69–77) and 1 µm (Figs 62–64, 66–68, 78). Scale bar for Figs

70–77 is shown in Fig. 69.

Actinella pulchella K. Sabbe & D. Hodgson, sp.

nov.

Figs 1, 79–100

Cellulae clavatae aspectu cincturae, 22±5–70±0(48±9³11±7) µm longae (n¯ 42). Chromatophoraduo, elongata, ad valvas appressa. Valvae clavatae,

semi-arcuatae, margine ventrali concava et margine

dorsali convexa, 1±5–3±5 (2±6³0±4) µm latae in me-dia parte. Capitus-polus 2±1–5±6 (3±4³0±8) µm latus,leviter tumescens in latere ventrali, sub-rostratus ad

rostratum. Basis 1±0–2±2 (1±6³0±3) µm lata, nontumescens, rotundata. Striae punctatae, 18–23

(20±1³1±2) in 10 µm, ad centrum parallelae, apices

Dow

nloa

ded

by [

193.

191.

134.

1] a

t 23:

52 1

6 Ja

nuar

y 20

12

K. Sabbe et al. 333

Figs 79–100. SEM (Figs 79–86) and light (Figs 87–100) micrographs of Actinella pulchella from different localities. Figs

80–82, 85, 86, 87–91, 94, 96, 97, Lake Crater, Tasmania (holotype population) ; Figs 79, 83, 84, 98, 99, Lake Spicer,

Tasmania; Fig. 93, Lake Rhona, Tasmania; Figs 95, 100, Reservoir 2, Tasmania; Fig. 99, Lake Rolleston, Tasmania; Fig.

92, Stewart Island, New Zealand. Fig. 79. External dorsal view of girdle and headpole. Note the longitudinal rows of

puncta on the copulae and the distinct subapical spines on the headpole. Fig. 80. External valve view showing rimoportula

opening at the footpole (arrowhead). Fig. 81. External view of the headpole. Note the small marginal spines along the

dorsal valve margin. Fig. 82. External girdle view of the headpole. Fig. 83. Internal footpole view showing the helictoglossa

and the rimoportula (arrowhead). Fig. 84. Internal valve view. Fig. 85. Internal headpole view with helictoglossa and small

rimoportula (arrowed). Fig. 86. External foot pole view showing the rimoportula opening (arrow). Figs 87–95. Valve views

showing variation in shape and size. Fig. 96. Valve and girdle view of headpole of a single frustule. Fig. 97. Footpole of the

same frustule as in Fig. 96, at different focus. Fig. 98. Girdle view of head pole showing valve with and without subapical

spine. Fig. 99. Girdle view. Fig. 100. Girdle view of recently divided cell. Scale bars represent : 10 µm (Figs 84, 87–100) and

1 µm (Figs 79–83, 85, 86). Scale bar for Figs 88–97, 99–100 is shown in Fig. 87.

versus leviter radiatae. Areolae parvae, circulares ;

structura velorum incognita (possibiliter erosa).

Spina distincta subapicalis ad capito-polo saepe

praesens. Margo valvae spinulis plerumque

praedita. Sternum nullum vel angustum et indis-

tinctum. Raphe brevis magnopere in limbo

Dow

nloa

ded

by [

193.

191.

134.

1] a

t 23:

52 1

6 Ja

nuar

y 20

12


Figs 101–114. SEM and light micrographs of Actinella spp. Figs 101–105. SEM (Figs 101, 102) and light (Figs 103–105)

micrographs of Actinella tasmaniensis from Lake Spicer (Tasmania). Figs 106–113. Light micrographs of Actinella

brasiliensis from Iganape (Donkin 2523, Surinam). Fig. 114. SEM micrograph of Actinella punctata from an unnamed lake

on Mount Giluwe (Papua New Guinea), showing the rimoportula (arrowhead) at the headpole. Figs 101, 102. Internal view

of the headpole and footpole of a single valve. The rimoportulae are arrowed. Fig. 103. Valve view. Note the position of

the raphe on the valve face margin. Figs 104, 105. Details of headpole and footpole of a single valve. The rimoportulae

have been arrowed. Figs 106, 108. Valve views. Figs 107, 109. Girdle views. Detail of footpole in Fig. 109 shows the two

helictoglossae and the rimoportula in the valve on the right (arrowhead). Figs 110, 111. Details of headpole at two different

foci showing the stria pattern and the rimoportula (arrowhead in Fig. 111). Figs 112, 113. Details of footpole of the same

valve as in Figs 110 and 111 at two different foci showing the raphe fissure and the stria pattern (Fig. 113). Fig. 114.

Internal view of the headpole showing the position of the raphe and helictoglossa, and the rimoportula (arrowhead).

valvarum sita ; apices distales earum in facie

valvarum flexi. Helictoglossae distinctae, in latere

ventrali valvae positae semper manifestae. Rimo-

portula probabiliter una, ad laterem ventralem basis

posita, sed nonnumquam quoque in parte apicali

capiti-poli. Cingulum ex 4 copulis apertis ligulatis

porosis constans.

Cells clavate in girdle view, 22±5–70±0(48±9³11±7) µm long (n¯ 42). Plastids two,elongate, valve-appressed. Valves clavate, semi-

Dow

nloa

ded

by [

193.

191.

134.

1] a

t 23:

52 1

6 Ja

nuar

y 20

12

K. Sabbe et al. 335

arcuate, with ventral margin concave and dorsal

margin convex, 1±5–3±5 (2±6³0±4) µm wide at mid-point. Headpole 2±1–5±6 (3±4³0±8) µm wide, slightlybulged on the ventral side, sub-rostrate to rostrate.

Footpole 1±0–2±2 (1±6³0±3) µm wide, not tumescent,rounded. Striae punctate, 18–23 (20±1³1±2) in10 µm, parallel in the centre to slightly radiate at the

poles. Velum structure unknown (possibly eroded).

A distinct, subapical spine is often present on the

headpole. Small spines are usually present along the

valve margin. Sternum absent or narrow and

indistinct. Raphe short, largely situated on the valve

mantle ; distal ends bent onto the valve face.

Helictoglossae distinct, clearly visible on the ventral

side of the valve. Rimoportula probably one per

valve, lying on the ventral side of the footpole, but

sometimes also in the apical part of the headpole.

Cingulum composed of 4 open, ligulate, porous

copulae.






T : Crater Lake, Tasmania, Australia.

A. pulchella was previously illustrated as Actinella

sp. 1 (partim) in Vyverman et al. (1995, pl. 4, figs

9–10, pl. 5, figs 1–5, 7, pl. 21, figs 4–9). It has two

elongate, often curled, plastids which lie below the

valves (Fig. 1) and which are characterized by two

small round structures (pyrenoids?) near the centre

of the cell. Typically, the valves are slightly tu-

mescent on the ventral side of the headpole (Figs

87–91, 93–96), although the dorsal side can be

tumescent as well (Fig. 88) ; the valves from New

Zealand have a more pronounced tumescence at the

headpole (Fig. 92). The significance of this ob-

servation needs to be assessed (cf. also A.

aotearoaia). Many valves belonging to A. pulchella

are characterized by a distinct subapical spine (Figs

79–82, 96, 98–100) which can best be observed in

girdle view. Some valves lacked this spine, even

when the other valve within the frustule did possess

one (Fig. 98). Small marginal spines are present

along the valve face margin, though not in all

specimens (compare Figs 79, 81 and 82 with Fig.

80). The round areolae are occluded by vela but

their exact nature is unknown (Fig. 82). The sternum

is indistinguishable, even in SEM. Most rimo-

portulae were observed in the footpole (Figs 80, 83,

86) but occasionally also in the apex of the headpole

(Fig. 85). The areolae on the footpole are randomly

scattered and thus almost resemble an apical pore

field (Fig. 86). The cingulum is composed of 4 open,

curved copulae which have several longitudinal

rows of puncta each (Figs 79, 81, 82, 100).

Actinella pulchella is quite reminiscent of A.

brasiliensis (De Oliveira & Steinitz-Kannan, 1992;

de Souza & Moreira-Filho, 1999; Metzeltin &

Lange-Bertalot, 1998; Van Heurck, 1881). A.

brasiliensis specimens from Surinam (AWH slides

VIII 37 B 6 and IX 61 A 4, figs 106–113) correspond

well to the original description of this species in Van

Heurck (1881) and the illustrations in Schmidt’s

Atlas (Schmidt et al., 1874–1959). In the original

description, Actinella brasiliensis is 39–113 µm long,

7±3–9±2 µm wide at the headpole and 2±5–3±3 µm atthe footpole, and has 14–16 striae in 10 µm.

Specimens illustrated in Schmidt’s Atlas and the

ones from Surinam (Figs 106–113) correspond fully

to this size range except for stria density which can

be higher (up to 19 striae in 10 µm). The apical point

is dorsal (Figs 106, 108, 110, 111), rarely medial (in

the smaller specimens; cf. Van Heurck 1881, pl.

XXXV, fig. 19). A rimoportula is present at the

head or footpole (Figs 109 and 111 respectively) ;

note that a footpole rimoportula is only present in

one valve of the frustule shown in Fig. 109. A.

pulchella has a significantly narrower headpole and

higher stria density than A. brasiliensis. A large

subapical spine was never observed in A. brasiliensis

(cf. also Metzeltin & Lange-Bertalot, 1998).

D : Actinella pulchella is the most com-

mon and widespread Actinella species in Tasmania,

but like the other Tasmanian species it is absent

from the eastern lakes. Valves belonging to this

species were also observed in samples from Stewart

Island (New Zealand, Fig. 92).

Actinella punctata Lewis

Fig. 114

D : See Kociolek et al. (1997).

D : A. punctata has hitherto only been

reported from North America and Scandinavia

(Kociolek et al., 1997). In the present study, a few,

usually broken valves belonging to this species were

found in the same oligotrophic highland tarns of

Mount Giluwe (Papua New Guinea) as A.

giluwensis. This constitutes the first confirmed re-

cord of this species for the Southern Hemisphere

and outside North America and Europe.

Actinella tasmaniensis Hustedt

Figs 101–105

D : See Hustedt (1952).

Dow

nloa

ded

by [

193.

191.

134.

1] a

t 23:

52 1

6 Ja

nuar

y 20

12


This species had hitherto only been observed in LM

(Simonsen, 1987; Vyverman et al., 1995). SEM

observations (Figs 101, 102) confirm the presence of

two rimoportulae per valve, one just below the

footpole helictoglossa and one in the apex of the

headpole. These rimoportulae are also visible in LM

(Figs 104, 105). Note the position of the raphe,

which runs alongside the valve face}mantle marginand which is clearly visible in valve view (Fig. 103).

Observations on live material revealed that A.

tasmaniensis, like A. punctata (Lewis 1863), forms

small stellate colonies on diverse submerged sub-

strata.

Discussion

All the above-described species are more or less

heteropolar, both in valve and in girdle view, have a

simple raphe structure and possess rimoportulae.

They have therefore been assigned to the genus

Actinella (Round et al., 1990). To our knowledge,

plastid structure has not been documented before in

this genus. Our observations on live A. aotearoaia

and A. pulchella show that the organization and

structure of the plastids is similar to that of Eunotia,

i.e. there are two elongate, valve-appressed plastids

per valve.

The validity of the genera Actinella and Desmo-

gonium with respect to Eunotia has been under

dispute for a long time (Hustedt, 1949; Cholnoky,

1954; Patrick & Reimer, 1966; Metzeltin & Lange-

Bertalot, 1998). Both Eunotia and Desmogonium

were described by Ehrenberg (1837 and 1848 re-

spectively) and neither of the (concise) type

descriptions contains direct reference to the features

which are nowadays considered to be characteristic

for these genera (such as the simple raphe structure

or the presence of rimoportulae; cf. above and

Round et al., 1990). The main distinction between

these two genera in the protologues concerns the

type of colony formation in Desmogonium (‘Lorica

(…) bacillaris (nec cuneata nec lanceolata)

fasciculatim in series ramosas dichotomas evoluta,

arbusculam referens’ – Frustule (…) rod-shaped

(not cuneate nor lanceolate) fasciculately developed

in dichotomously branched series, reminiscent of a

small tree ’ ; Ehrenberg, 1848). All other distin-

guishing characteristics have been added a

posteriori. According to the generic circumscription

of Patrick & Reimer (1966), Desmogonium thus

differs from Eunotia in the possession of spines

along both the ventral and dorsal valve margins and

its colony growth form, which they describe as

‘zigzag’. They also point out that usually two

rimoportulae (‘ jelly pores ’) are visible at both ends

of the valve in Desmogonium (in Eunotia there is

mostly one rimoportula per valve; Vyverman et al.,

1998). Metzeltin & Lange-Bertalot (1998) argue

that the main discriminating morphological features

of Desmogonium and Eunotia are insufficient for

separation at the genus level and formally propose a

rank alteration for Desmogonium to become a

subgenus of Eunotia. However, we believe that,

given the fact that no thorough studies have yet

been made of their types (D. guinanense Ehrenberg

and E. arcus Ehrenberg), the two genera should be

kept separate.

Metzeltin & Lange-Bertalot (1998) hold the

opinion that Actinella should also be reduced to the

rank of subgenus (of Eunotia) because hetero-

polarity would exist in Eunotia and isopolarity in

Actinella (cf. also Cholnoky, 1954). However, they

do not propose a formal recombination as, ac-

cording to the authors, this would involve the

creation of a large number of synonyms (actually

only 36; cf. Table 1). Little is known about the

taxonomic value of heteropolarity versus iso-

polarity in diatoms. Asymmetry about the trans-

apical and pervalvar axes is predominantly found in

taxa that are attached to a substratumvia amucilage

stalk and especially when the cells grow close

together in stellate or fan-shaped colonies.

Examples include the araphid genera Licmophora

Agardh, Meridion Agardh and Distrionella

Williams but also raphid genera such as

Rhoicosphenia Grunow, Gomphonema Ehrenberg

and Didymosphenia Schmidt (cf. Williams, 1990;

Round et al., 1990). The fact that a common life

form is found in phylogenetically distant groups

(both araphid and raphid lineages) suggests that it

has arisen on several occasions. This is in accord-

ance with the results of cladistic analyses based on

morphological and cytoplasmic features which have

shown that heteropolarity is a convergent feature,

within both the araphid (Williams, 1990) and the

raphid groups (Kociolek & Stoermer, 1986, 1988)

investigated. Moreover, heteropolarity is con-

sidered to be an autapomorphic feature at the genus

level in the above-mentioned raphid and araphid

taxa (the single isopolar Meridion species (Williams,

1985) should be placed in a separate genus according

to Williams (1997)). By analogy with heteropolarity,

Mann & Stickle (1997) concluded that dorsi-

ventrality (i.e. amphoroid symmetry) has sporadi-

cally evolved in different raphid, benthic diatom

groups in taxa living on sandy and rocky substrata.

Both features therefore appear to be an adaptation

to a specific life form.

In Actinella, heteropolarity is also obligatory for

membership of the genus. A. punctata, the type of

the genus, is characterized by heteropolar valves,

both in valve and girdle view (Lewis, 1863; Kociolek

et al., 1997). Heteropolarity in girdle view appears

to be the case for most Actinella species (e.g. this

study; Moser et al., 1998), although it is unfortu-

nately often not illustrated (e.g. Van Heurck, 1881;

Dow

nloa

ded

by [

193.

191.

134.

1] a

t 23:

52 1

6 Ja

nuar

y 20

12

K. Sabbe et al. 337

Hustedt, 1952), even in recent papers (da Costa

1995; Moser et al., 1998; Metzeltin & Lange-

Bertalot, 1998). Eunotia species are always rec-

tangular or trapezial (e.g. Krammer & Lange-

Bertalot, 1991, t. 164, figs 10, 11) in girdle view (the

latter shape can also be observed in Eunophora ;

Vyverman et al., 1998). To date, group membership

of Eunotia and Actinella has been exclusively based

on cell polarity, except when the author considered

them congeneric. For example, the strongly hetero-

polar diatom Eunotia actinelloides Cholnoky (prob-

ably synonymous with Eunotia asymmetrica

Cholnoky (Cholnoky, 1954)) was explicitly

described as a Eunotia species because Cholnoky

held the opinion that the two genera would be

merged sooner or later (note that E. actinelloides

was later transferred to Actinella (A. cholnokii),

although nothing is as yet known about the sym-

metry of the frustule in girdle view). The remainder

of heteropolar Eunotia species (e.g. E. cuneiformis

Manguin, E. raytonensis Cholnoky, E. fallax var.

aequalis Hustedt, E. tenella var. capensis Cholnoky)

all belong to the species cluster around Eunotia

rhomboidea Hustedt and might even be conspecific

with it (cf. Coste & Ricard, 1982; Krammer &

Lange-Bertalot, 1991). E. rhomboidea valves can be

both iso- or heteropolar ; in girdle view, however,

they are rectangular or rhombic. The morphology

and exact taxonomic position of this species (or

species group) requires further investigation. On the

whole, valve heteropolarity in Eunotia cells is the

exception rather than the rule (cf. the Eunotia plates

in e.g. Krammer & Lange-Bertalot, 1991 and

Metzeltin & Lange-Bertalot, 1998: not a single

heteropolar valve). At present, we believe that the

distinction between Eunotia and Actinella on the

basis of cell symmetry (both in girdle and valve

view) can be maintained. In addition, rimoportula

number and position appears to be more variable

within Actinella than in Eunotia (see below). Further

studies, incorporating reproductive and molecular

information, are necessary to resolve phylogenetic

relationships within the Eunotiophycidae.

Cultria Metzeltin & Lange-Bertalot, the newly

described heteropolar subgenus of the genus

Eunotia, differs from Actinella only in the presence

of a ‘basal plateau’ at the footpole (Metzeltin &

Lange-Bertalot, 1998). Whether or not Cultria, like

Actinella, is also heteropolar in girdle view is not

mentioned in the protologue of Cultria and cannot

be seen in the illustrations provided. The absence of

spines in Cultria is not a good diagnostic feature as

this seems to be variable within Actinella (e.g. spines

are facultative in A. pulchella ; Figs 79–82). We

therefore see no reason to distinguish between

Actinella and Cultria on the basis of a single feature,

viz. the basal plateau, as repeatedly advocated by

the authors themselves (e.g. Lange-Bertalot, 1997).

Species distinction within the genus Actinella is

mainly based on cell dimensions, shape, stria den-

sity, presence and position of rimoportulae, and

growth form. In the two largest species, A.

tasmaniensis (cf. also Hustedt, 1952) and A.

giluwensis (Figs 22, 26), there are two rimoportulae

per valve, as in the type species A. punctata (Round

et al., 1990). In A. brasiliensis, some valves have two

rimoportulae, but most valves have only one rimo-

portula. In A. aotearoaia, A. indistincta and A. parva

there is one rimoportula per valve, either at the

head- or footpole; within a frustule, they are

diagonally opposite. This was also observed in A.

guinanensis (Metzeltin & Lange-Bertalot, 1998) and

is also the case in most Eunotia species (Vyverman et

al., 1998). Finally, in Actinella muylaertii, rimo-

portulae may be present at both footpoles within a

frustule (Fig. 47). It thus appears that rimoportula

number and position is rather variable in Actinella,

as in Eunophora (Vyverman et al., 1998), but unlike

in Eunotia, Peronia and Desmogonium, where this is

a more constant generic feature (Round et al.,

1990).

All newly described Actinella species were found

in dystrophic to (ultra-)oligotrophic waters, where

they can be a dominant component of the litoral

diatom assemblages (e.g. A. parva up to 41% in

Lake Spicer, Tasmania; Vyverman et al., 1996).

With the exception of A. tasmaniensis, all species in

Tasmania are predominantly confined to the humic

western lakes, characterized by low pH (! 5) andan ion composition close to that of seawater (Tyler,

1992; Vyverman et al., 1996). In the anthro-

pogenically acidified Owen Tarn (Tasmania), A.

pulchella is the dominant species (up to 40% relative

abundance) in the top layers of the sediments

(inferred pH in these layers is approximately 4±2;Hodgson et al., 2000), suggesting a high tolerance

of acidity. A. tasmaniensis is largely confined to

oligotrophic lakes but also occurs in more humic

conditions. Scattered observations on live material

of some species (A. aotearoaia, A. tasmaniensis and

A. pulchella) revealed that they live attached to

various types of substrata, ranging from flocculent

detrital matter, and mucous biofilms on submerged

rocks to mosses and macroalgae.

The geographical distribution patterns of the

species within the genus Actinella raise some

interesting biogeographical questions, as there ap-

pear to be large differences in geographic range

amongst species (Table 1). Only two species, A.

brasiliensis and A. punctata, have a worldwide

distribution. A. brasiliensis is common and wide-

spread in the Amazon basin (South America; e.g.

Van Heurck, 1881; De Oliveira & Steinitz-Kannan,

1992; Metzeltin & Lange-Bertalot, 1998) but has

also been reported from Japan (e.g. Okuno, 1964).

The West African reports by Carter & Denny (1982)

Dow

nloa

ded

by [

193.

191.

134.

1] a

t 23:

52 1

6 Ja

nuar

y 20

12


and numerous other records, mainly from Asia

(Russia, e.g. Skortzow, 1929) but also from

Australia (Foged, 1979), need to be verified. A.

punctata is known from North America and

Scandinavia (Kociolek et al., 1997) and Papua New

Guinea (this study). All other Actinella species have

more limited distributions. It is striking that the

Southern Hemisphere regions are strongholds for

species diversity in this genus (which disproves the

statement in Round et al. (1990) that the genus is

mainly tropical in distribution) and that each major

biogeographical region has its own endemic species.

At least 9 Actinella species are endemic to

Australasia (Table 1). Even at smaller spatial scales

within this region, there are marked differences in

geographic range: some species occur over a wide

range (e.g. A. aotearoaia : New Zealand, Tasmania

and the Australian mainland), others have more

limited ranges (e.g. A. indistincta and A. pulchella :

Tasmania and New Zealand), while still others are

known from a few lakes only (A. giluwensis and A.

muylaertii). These findings are in accordance with

recent studies which indicate that endemism in

diatoms (but also in other microalgal groups such as

Chlorophyta and Chrysophyta) might be more

widespread than previously thought (cf. Mann &

Droop, 1996; Tyler, 1996; Williams, 1996; Passy et

al., 1997; Spaulding & Kociolek, 1998; Spaulding et

al., 1999). This is especially true for the Australasian

region (Vyverman, 1988; Vyverman et al., 1997;

1998; Moser et al., 1998; Moser, 1999; Sabbe et al.,

2000). However, studies on groups such as ciliates

(Esteban et al., 2000), heterotrophic chrysophytes

(Finlay & Clarke, 1999) and heterotrophic

flagellates (Patterson, 1999) emphasize that protists

in general are ubiquitous and that community

composition is predominantly determined by habi-

tat type. In the opinion of these authors, extrinsic

factors such as undersampling of rare habitats but

also of rare taxa or resting stages lead to erroneous

claims of endemism. This would mean that the

dilute, humic lakes in the alpine regions of Tasmania

and the south Island of New Zealand, which are

a major stronghold of endemic diatoms (cf.

Vyverman et al., 1997, 1998; this study), constitute

unique environments on a worldwide scale, and that

the so-called endemics are simply rare (i.e. restricted

to a rare habitat) but not truly endemic. However,

lakes with similar limnological characteristics exist

in other, better-studied parts of the world (e.g.

Henriksen et al., 1998), and, as many of the endemic

diatoms have very distinct morphological features,

it is unlikely that they would have been overlooked.

We therefore believe that they are true endemics,

and that factors other than habitat rarity have

played a role in creating restricted distributions.

The case of the genus Actinella, with large inter-

specific differences in geographic ranges, shows that

this hypothesis does not have to contradict the

findings from other, possibly truly ubiquitous

protist groups. It does, however, indicate that

caution is called for when extrapolating results from

one taxonomic group (or even taxon) to the other.

Finally, how and to what degree climatic, geo-

logical, biological and ecological processes influence

there biogeographical patterns is still largely un-

known. Studies on the possible impact of such

diverse phenomena as plate tectonics (Coleman,

1996), dispersal capacities and evolutionary age

(Coleman et al., 1994; Theriot, 1992) and human

activities (such as introductions, cf. Harper, 1994;

Edlund et al., 2000; or extinctions, cf. Julius et al.,

1998) on microalgal distributions indicate, however,

that there is probably more to protist biogeography

than a simple ‘everything is everywhere ’.

Acknowledgements

K.S. is a Senior Research Fellow with the Fund for

Scientific Research (FWO, Belgium). Financial

support for W.V. and K.S. was provided by FKFO

project no. G.0024.96. We gratefully acknowledge

the support of the National Science Foundation

(grant g INT-9417225 and INT-9908522) forR.L.L. and a Graduate Fellowship for S.N.F. The

New Zealand Foundation for Research Science and

Technology provided funding for E. Bergey (con-

tract 1820, Biodiversity of Freshwater Organisms)

and B. Biggs (contract 1519, Environmental Hy-

drology and Habitat Hydraulics). Dr G. Van

Steenbergen of the Royal Society of Zoology

(Antwerp) is thanked for the loan of the Van Heurck

collection slides. We are greatly indebted to Dr

Hallegraeff and colleagues (Botany Department,

University of Tasmania) for the use of their micro-

scopical facilities and Dr Kociolek for advice on

parts of the manuscript. Drs P. Compe' re (NationalBotanic Garden, Brussels), R. Jahn (Botanisches

Garten und Botanisches Museum, Berlin) and D.

Lazarus (Museum fu$ r Naturkunde, Humboldt Uni-versity, Berlin) are thanked for help with the

translation and understanding of the Ehrenberg

manuscripts. Many thanks are also due to Dr Cathy

Kilroy and Dr John Ferris for the collection of

diatom samples from remote sites in New Zealand

and Australia. Dr P. Tyler (Deakin University) is

thanked for logistical support and inspiring dis-

cussions on Tasmanian freshwater algae.

References

A (1975). Proposals for a standardization of diatom

terminology and diagnoses. Nova Hedwigia, Beih., 53 : 323–354.

B, P. & M, E. (1949). Contribution a' l’e! tude de laflore algale d’eau douce de Madagascar : le Lac Tsimbazaza.

MeUm. l ’Inst. Sci. Madagascar, SeU r. B., 2 : 161–190.B, J. (1896). Diatome! es mioce' nes: espe' ces nouvelles. Le

Diatomiste, 2 : 229–247.

Dow

nloa

ded

by [

193.

191.

134.

1] a

t 23:

52 1

6 Ja

nuar

y 20

12

K. Sabbe et al. 339

C, J.R. & D, P. (1982). Freshwater algae of Sierra Leone.

III. Bacillariophyceae. Nova Hedwigia, Beih., 73 : 281–331.

C, J.R. & D, P. (1987). Freshwater algae of Sierra Leone.

IV. Bacillariophyceae. Part (ii) : Diatoms from the coastal region

of the southern province. Nova Hedwigia, 44 : 229–275.

C, B.J. (1954a). Diatomeen und einige andere Algen aus

dem ‘deHoek’-reservat in Nord-Transvaal. Bot.Not., 3 : 269–296.

C, B.J. (1954b). Ein Beitrag zur Kenntnis der Algenflora

des Mogol-Flusses in Nord-Ost Transvaal. Or st. Bot. Zeitschr.,101 : 118–139.

C, B.J. (1955). Hydrobiologische Untersuchungen in

Transvaal. I. Vergleichung der herbstlichen Algengemeinschaften

in Rayton-vlei und Leeufontein. Hydrobiologia, 7 : 137–209.

C, A.W. (1996). The Indian connection, crucial to re-

construction of the historical biogeography of freshwater algae:

examples among Volvoceae (Chlorophyta). NovaHedwigia, Beih.,

112 : 477–482.

C, A.W., S, A. & G, L.J. (1994). Molecular

delineation of species and syngens in Volvocacean green algae

(Chlorophyta). J. Phycol., 30 : 80–90.

C, M. & R, M. (1982). Contribution a' l’e! tude desdiatome! es d’eau douce des Seychelles et de L’Ile Maurice.Cryptogamie, Algol., 3 : 279–131.

C, E.J. & R, R. (1980). The striae of pennate diatoms. In

Proceedings of the Sixth Symposium on Recent and Fossil Diatoms

(Ross, R., editor), 267–278. Otto Koeltz, Koenigstein.

D C, J.C.F. (1995). Diatoma! ceas (Bacillariophyceae) daReserva Biolo! gica de poc: o das Antas, municı!pio de Silva Jardim,Rio de Janeiro, Brasil. Iheringia, Ser. Bot., 46 : 57–143.

D O, P.E. & S-K, M. (1992). The diatom

flora (Bacillariophyceae) of the Cuyabeno Faunistic Reserve,

Ecuadorian Amazonia. Nova Hedwigia, 54 : 515–552.

D S, M.G.M. & M-F, H. (1999). Diatoms

(Bacillariophyceae) from two aquatic macrophyte banks from

Lagoa Bonita, Distrito Federal, Brazil. I. Thalassiosiraceae and

Eunotiaceae. Bull. Natl. Plant. Belg., 67 : 259–278.

E, M.B., T, C.M., S, C.L. & S, E.F.

(2000). Thalassiosira baltica (Grunow) Ostenfeld (Bacillario-

phyta), a new exotic species in the Great Lakes. Can. J. Fish.

Aquat. Sci., 57 : 610–615.

E, C.G. (1837). U> ber ein aus fossilen Infusorienbestehendes, 1832 zu Brod verbacknes Bergmehl von den Grenzen

Lapplands in Schweden. Bericht uX ber die zur Bekanntmachunggeeigneten Verhandlunger der KoX nigl. preuss. Akademie derWissenschaften zu Berlin : 43–45.

E, C.G. (1848). Die Mikroskopischen Lebensformen. In

Reisen in Britisch-Guiana in den Jahren 1840–1844, Part 3

(Schomburgk, R., editor), 537–544. J.J. Weber, Leipzig.

E, G.F., F, B.J., O, J.L. & T, P.A. (2000).

Ciliated protozoa from a volcanic crater-lake in Victoria,

Australia. J. Nat. Hist., 34 : 159–189.

F, B.J. & C, K.J. (1999). Ubiquitous dispersal of

microbial species. Nature, 400 : 828.

F, C.W. (1917). Su$ ss wasserdiatomeen Ober-Ja$ mtland inSchweden. Ark. Bot., 14 (21) : 1–68.

F, N. (1978). Diatoms in Eastern Australia. Bibl. Phycol., 41 :

1–242.

F, N. (1979). Diatoms in New Zealand, the North Island. Bibl.

Phycol., 47 : 1–224.

H, B.T. & MK, I.D. (1986). Chemical limnology in

Australia. In Limnology in Australia (De Deckker, P. & Williams,

W.D., editors), 3–31. Junk Publishers, Dordrecht.

H, M.A. (1994). Did Europeans introduce Asterionella

formosa Hassall to New Zealand?. In Proceedings of the 11th

International Diatom Symposium (Kociolek, J.P., editor),

479–484. The California Academy of Sciences, San Francisco.

H, I. (1964). An Introductory Account of the Smaller Algae of

British Coastal Waters, part V, Bacillariophyceae (Diatoms).

Her Majesty’s Stationery Office, London.

H, A., S, B.L., M, J., W, A.,

H, R., C, C., J, J.P., F, E. & M,

T. (1998). Northern European Lake Survey, 1995. Finland,

Norway, Sweden, Denmark, Russian Kola, Russian Karela,

Scotland and Wales. Ambio, 27 : 80–91.

H!, F.J. (1902). Les DiatomeU es d ’Auvergne. PremierMeUmoire. Librairie des Sciences naturelles, Paris.

H, D., V, W., C-L, A & T, P.A.

(2000). From rainforest to wasteland in 100 years : the limno-

logical legacy of the Queenstown mines, Western Tasmania.

Arch. Hydrobiol., 149 : 153–176.

H, F. (1949). Su$ sswasser-Diatomeen aus dem Albert-Nationalpark in Belgisch Kongo. Expl. Parc Natl. Albert. Mission

Damas (1935–1936), 8 : 1–199.

H, F. (1952). Neue und wenig bekannte Diatomeen. III.

Phylogenetische Variationen bei den rhaphidioiden Diatomeen.

Ber. Dtsch. Bot. Ges., 65 : 133–144.

H, F. (1965). Neue und wenig bekannte Diatomeen. IX.

Su$ sswasser-Diatomeen aus Brasilien, insbesondere desAmazonasgebietes. Int. Rev. Ges. Hydrobiol., 50 : 391–410.

K, J.P. & R, K. (1998). Raphe vestiges in ‘Asterionella ’

species from Madagascar : evidence for a polyphyletic origin of

the araphid diatoms? Cryptogamie, Algol., 19 : 57–74.

K, J.P. & S, E.F. (1986). Phylogenetic relationships

and classification of monoraphid diatoms based on phenetic and

cladistic methodologies. Phycologia, 25 : 297–303.

K, J.P. & S, E.F. (1988). A preliminary investi-

gation of the phylogenetic relationships among the freshwater,

apical pore field-bearing cymbelloid and gomphonemoid diatoms

(Bacillariophyceae). J. Phycol., 24 : 377–385.

K, J.P., R, K. & W, D.M. (1997). Taxonomy,

ultrastructure and biogeography of the Actinella punctata species

complex (Bacillariophyta: Eunotiaceae). Nova Hedwigia, 65 :

177–193.

K, K. & L-B, H. (1991). Bacillariophyceae.

Part 3. Centrales, Fragilariaceae, Eunotiaceae. In SuX sswasserfloravonMitteleuropa (Ettl,H.,Gerloff, F.,Heynig,H. &Mollenhauer,

D., editors). G. Fisher, Stuttgart.

L-B, H. (1997). As a practical diatomist, how does one

deal with the flood of new names? Diatom, 13 : 9–12.

L, F.W. (1863). On some new and singular intermediate forms

of diatomaceae. Proc. Acad. Nat. Sci. Philad., 15 : 336–346.

M, D.G. & D, S.J.M. (1996). Biodiversity, biogeography

and conservation of diatoms. Hydrobiologia, 336 : 19–32.

M, D.G. & S, A.J. (1997). Sporadic evolution of

dorsiventrality in raphid diatoms, with special reference to Lyrella

amphoroides sp. nov. Nova Hedwigia, 65 : 59–77.

M, D. & L-B, H. (1998). Tropical diatoms of

South America: I. Icon. Diatomol., 5 : 3–695.

M$ , K. (1951). Beitra$ ge zur Kenntnis der rezentenDiatomeenflora Ostkareliens. Ann. Soc. Zool. Bot. Fen. Vanamo,

25 : 1–35.

M, G. (1999). Die Diatomeenflora von Neukaledonien.

Systematik, Geobotanik, O> kologie, ein Fazit. Bibl. Diatomol., 43 :1–205.

M, G., L-B, H. & M, D. (1998). Insel der

Endemiten. Geobotanisches Pha$ nomen Neukaledonien. Bibl.Diatomol., 38 : 1–464.

N, J.L. (1983). A new method using hexamethyldisilazane for

preparation of soft insect tissues for scanning electron

microscopy. Stain Tech., 58 : 347–351.

O, H. (1964). Part V: Fossil diatoms. In Diatomeenschalen im

elektronenmikroskopischen Bild (Helmcke, J.-G. & Krieger, W.,

editors). J. Cramer, Weinheim.

P, S.I., K, J.P. & L, R.L. (1997). Five new

Gomphonema species (Bacillariophyceae) from rivers in South

Africa and Swaziland. J. Phycol., 33 : 455–474.

P, R. & R, C.W. (1966). The diatoms of the United

States, exclusive of Alaska and Hawaii. Vol. 1. Fragilariaceae,

Eunotiaceae, Achnanthaceae, Naviculaceae. Monogr. Acad. Nat.

Sci. Philad., 13 : 1–688.

R, R., C, E.J., K, N.I., M, D.G., P,

T.B.B., S, R. & S, P.A. (1979). An amended ter-

Dow

nloa

ded

by [

193.

191.

134.

1] a

t 23:

52 1

6 Ja

nuar

y 20

12


minology for the siliceous components of the diatom cell. Nova

Hedwigia, Beih., 64 : 513–533.

R, F.E., C, R.M. & M, D.G. (1990). The

Diatoms: Biology and Morphology of the Genera. Cambridge

University Press, Cambridge.

S, K., V, K. &

Documents

Six new Actinella (Bacillariophyta) species from Papua New ... · Six new Actinella (Bacillariophyta) species from Papua New Guinea, Australia and New Zealand: further evidence for