OLR (1984) 31 (12) E. Biological Oceanography 891

Beaufort Sea (Arctic Ocean) bivalve Molinsca. Mar. Ecol.-Prog. Ser., 17(2):125-134. Coll. of Oceanogr., Oregon State Univ., Corvallis, Oreg. 97331, USA.

84:6234 Fenwick, G.D., 1984. Life history and population

biology of the giant ustracod Letwoleberis zealan- d~ca (Baird, 1850) (Myoducopida). J. expl mar. Biol. Ecol., 77(3):255-289.

A 2-year study of L. zealandica using 'random core-sampling of medium sand bottom' revealed 7 instars. In the last instar, when sexual maturity was reached, males became rare. Three cohorts com- prised the population at any one time with each cohort split into 'fast- and slow-growing individuals.' Females produced but one brood of 37 eggs (on average) per lifetime. Mortality and development time also were investigated. Findings are compared with the limited information available on myodo- copid biology. Dept. of Zool., Univ. of Canterbury, Christchurch, New Zealand. (ahm)

84:6235 Harvell, C.D., 1984. Predator-induced defense in a

marine bryozoan. Science, 224(4655): 1357-1359.

The cheilostome bryozoan Membranipora mem- branacea rapidly produced defensive spines when preyed upon by slowly feeding, 'trophically spe- cialized and generalized' nudibranchs. The spines reduced the rates of nudibranch feeding and influ- enced feeding patterns. Such predator-induced de- fenses could be common in clone-forming or colo- nial taxa; implications for coevolutionary and paleoecological research are discussed. Friday Har- bor Labs., Friday Harbor, Wash. 98250, USA. (mjj)

84:6236 Hutchings, J.A. and R.L. Haedrich, 1984. Growth

and population structure in two species of bivalves (Nuculanidae) from the deep sea. Mar. Ecol.- Prog. Set., 17(2): 135-142.

Nuculana pernula and Yoldia thraciaeformis were collected at depths of 895 to 1500 m in the northwest Atlantic off Newfoundland. Sizes attained by both species approach or exceed previously recorded maximum lengths; populations are dominated by large individuals. Little overlap in lengths between the cohabiting species is observed. Rapid growth rates early in life, heavy predation on young individuals by fish and boring gastropods, and size-related mechanisms reducing niche overlap may explain the observed size structure. Dept. of Biol., Memorial Univ., St. John's, Newfoundland AIB 3X9, Canada.

84:6237 Worrall, C.M. and J. Widdows, 1984. Investigation of

factors influencing mortality in Myfflus edulis L. Mar. Biol. Letts, 5(2):85-97. Nat. Environ. Res. Council, Inst. for Mar. Environ. Res., Prospect Place, The Hoe, Plymouth PLI 3DH, UK.

E230. Crustacea

84:6238 Alldredge, A.L., B.H. Robison, A. Fleminger, J.J.

Torres, J.M. King and W.M. Hamner, 1984. Direct sampling and in-situ observation of a persistent copepod aggregation in the mesopelagic zone of the Santa Barbara Basin. Mar. Biol., 80(1):75-81.

Observations and sampling suggested that the aggregated copepodites (Calanus pacificus califor- nicus) were in diapause, related to the temporary cessation of upwelling in these waters and conse- quent diminishing surface food supply. The aggre- gation itself, however, was observed to be fed upon by numerous mesopelagic predators. Oceanic Biol. Group, Univ. of California, Santa Barbara, Calif. 93106, USA. (slr)

84:6239 Athersuch, John and D.J. Home, 1984. A review of

some European genera of the family Loxocon- chidae (Crustacea: Ostracoda). Zool. J. Linn. Soc., 81(1):1-22.

World distributions, paleoecological significance, stratigraphic ranges, systematics, taxonomy, and comparative morphology are considered for the Loxoconcha, Lindisfarnia, Sagmatocythere, Bonnyan- nella, Hirschmannia, and Elofsonia. All 6 genera have living representatives in the NE Atlantic and the Black and Mediterranean seas. Revised diagnoses are presented; the type species are illustrated together to point out possible relationships. BP Res. Centre, Sunbury, Middlesex TW15 7LN, UK. (ihz)

84:6240 Bamwell, F.H. and C.L. Thurman II, 1984. Tax-

onomy and biogeography of the fiddler crabs (Ocypodidae: genus Uca) of the Atlantic and Gulf coasts of eastern North America. Zool. J. Linn. Soc., 81(1):23-87.

The taxonomic status of Gulf coast fiddler crabs was clarified and their geographical distributions defined via 'extensive serial sampling' from Cape Cod (Massachusetts) to Mexico's Yucatan Peninsula. Of the 13 gulf species, 5 are endemic with a sixth