The composition, structure, and distribution of benthic ostracod fauna (Ostracoda, Myodocopa) in Antarctic waters
The benthic fauna of ostracods of the order Myodocopida of Antarctic waters is characterized by high diversity, relative species abundance, and a complicated taxonomic and ecological structure, with a simplified biogeographical structure. This fauna, which is distinguished by a high level of endemicity, although at a low taxonomic rank, includes a great share of deep-sea and subtidal elements. Ostracod populations of High and Low-Antarctic subzones differ qualitatively and quantitatively. A distinct impoverishment of fauna is observed in the region of the Antarctic divergence compared to the more northern areas. The number of species increases with depth to reach its maximum in the lower subtidal zone and on the upper continental slope at depths of 200–500 m. The number of species decreases with increasing depth. Myodocopida have not been yet found in the Antarctic waters deeper than 5000 m.
First record and description of male of Metavargula adinothrix Kornicker, 1975 (ostracoda: myodocopina) from the Southern Ocean
Previously unknown male and some juveniles of Metavargula adinothrix Kornicker, 1975 were identified in material which was collected by Germany R/V Polarstern from bathyal and abyssal depth of the Atlantic Sector of the Southern Ocean. Diagnosis, description and detailed illustrations of male of this species are presented. Morphological comparison is made between male and female of this species. The distribution of M. adinothrix in the Antarctic and Subantarctic waters is shown.
Myodocopid Ostracoda of the Beaufort Sea, Arctic Ocean
Kornicker, Louis S. Myodocopid Ostracoda of the Beaufort Sea, Arctic Ocean. Smithsonian Contributions to Zoology, number 456,40 pages, 19 figures, 3 tables, 1988.—Numerous bottom samples collected during 1971-1977 from the western half of the Beaufort Sea contained four species of myodocopid ostracodes, three new. The new species are described and illustrated, and a supplementary description is presented of Philomedes brenda (Baird, 18S0) based on the specimens from the Beaufort Sea. The most abundant species is P. brenda, which is circumpolar. The new species are endemic to the Beaufort Sea. Of these Scleroconcha ruffi is common, and the remaining two are extremely rare (Empoulsenia monothrix and Bathyleberis thrix). Samples were collected at depths of 25-4200 m, but myodocopid ostracodes were not present deeper than 1926 m. Relative abundances of P. brenda and S. ruffi differed in August of the adjacent years 1976,1977, at depths of 50-100 m, but not at depths of 25-40 m. Samples collected during October 1975, March, May, August, November 1976, and August 1977, suggest that P. brenda may be more abundant during March and May. Whether stations were with or without an ice cover seemed to have little effect on ostracode abundance. Females of both P. brenda and S. ruffi appear to bear eggs year-round. Species and genera between depths of 0-200 m (continental shelf and part of upper slope) in the Arctic and Antarctic are compared: Five of seven genera on the Arctic shelf also live on the Antarctic shelf (Simpson Index 71.4), but with no species in common. A hydrozoan colonizes the carapaces of some adult and ovigerous females of Philomedes brenda. Four other taxonomic actions not directly pertinent to this study are taken: Philomedes globosa digitiformis Chavtur, 1983, is raised to species rank as Philomedes digitiformis Chavtur, Asterope abyssicola Sars, 1869, is recombined as Prionotoleberis abyssicola (Sars), Asterope norvegica Sars, 1869, is recombined as Prionotoleberis norvegica (Sars), and Philomedes kadjakiensis Chavtur, 1983, is referred to Philomedes species inquirenda. OHPIOAL PUBLICATION DATE is handstampcd in a limited number of initial copies and is recorded in the Institution's annual report, Smithsonian Year. SEMES COVER DESIGN: The coral Montastrea caver nosa (Linnaeus). Library of Congress Cataloging-in-Publication Data Kornicker, Louis S.. 1919Myodocopid Ostracoda of the Beaufort Sea, Arctic Ocean. (Smithsonian contributions to zoology ; no. 456) Bibliography: p. 1. Myodocopid*. 2. Crustacea—Beaufort Sea. I. Title. D. Series. QL1.SS4 no. 456 591s 86-31530 [OL444.08] [595J'3]