Studies of Antarctic Pelagic Ostracoda

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Figure 6. A general scheme of vertical distribution of the major thecosomatous pteropod species in western antarctic waters.

species is based on their maximum concentration. The variation of depth range of each species depends upon location. References Deacon, G. E. R. 1937. The hydrology of the southern ocean. Discovery Reports, 15: 1-124.

Jacobs, S. S. 1965. Physical and Chemical Oceanographic Observations in the Southern Oceans: USNS Eltanin Cruises 7-15. Lamont Geological Observatory. Technical

Report l-CU-1-65. 321 p.

Jacobs, S. S. 1966. Physical and Chemical Oceanographic Observations in the Southern Oceans: USNS Eltanin Cruises 16-21. Lamont Geological Observatory. Technical

Report l-CU-66. 128 p. Mackintosh, N. A. 1960. The pattern of distribution of the antarctic fauna. Royal Society. Proceedings, B., 152: 624-631. Mackintosh, N. A. 1964. Distribution of the plankton in relation to the Antarctic Convergence. Royal Society. Proceedings, A., 281: 21-38.

Distribution of Antarctic Marine Fungi JACK W. FELL Institute of Marine Sciences University of Miami The immediate purpose of our mycological prograin is to determine the distribution of fungi in antarctic water masses from the Continent to the Subtropical Convergence. During 1966 and 1967, we participated in four cruises of USNS Eltanin and one of USCGC Eastwind. During the past year, the large number of fungi collected during these cruises has been examined at the Institute of Marine Sciences. September-October 1968

Preliminary results indicate that fungi having a unicellular growth phase predominate in the open ocean and that the filamentous forms appear to be restricted to the inshore regions. The most significant result was the observation that primitive Basidiomycetes are widely distributed in the antarctic seas. Previously, Basidiomycetes were considered to be rare or nonexistent in marine environments. Morphologically, these antarctic Basidiomycetes have the typical characteristics of yeasts. They have soft, cream- to white-colored colonies, unicellular budding cells, and form a pseudomycelium. This morphology suggests classification among the yeast genera, specifically the genus Candida, rather than the Basidiomycetes. The life cycles are, however, quite distinct from the yeasts. Haploid cells will mate to produce a binucleate mycelium with clamp connections. Karyogamy takes place in a heavy-walled teliospore, and meiosis occurs as the spore germinates via a promycelium. Haploid sporidia develop on the promycelium to complete the life cycle. This life history is analogous to that of the smut fungi. Terrestrially, smuts are obligate parasites that are extremely destructive to cereals and other commercially important plants. This fact suggests that the marine smut-like fungi may have an important saprophytic or parasitic role in the antarctic seas. This elucidation of the basidiomycetous life cycle considerably alters the phylogenetic concept of yeasts. Most yeasts, particularly the candidas, are considered to be imperfect forms of Ascomycetes (e.g., of the genus Saccharomyces). Details of this research will be published in the new edition of "The Yeasts, A Taxonomic Study" (Lodder, in press). For the same review, we have also prepared chapters on the genera Cryptococcus, Sterigmatomyces, and Rh odosporidium that include descriptions and discussions of yeasts from the Antarctic.

Studies of Antarctic Pelagic Ostracoda NORMAN S. HILLMAN Lamont Geological Observatory Columbia University Pelagic Ostracoda of the genus Conchoecia are represented -by about 23 species in antarctic waters between 500 S. and 70 0 S. Ostracoda collected from plankton hauls made on Eltanin cruises 9-24 have been examined. The quantitative seasonal distribution of Conch oecia species in the Pacific sector of the Antarctic is being studied. Many species have been collected further south than previously recorded, as summarized in 157

Southern extension of the distribution of pelagic Ostracoda Author and Lati- Cruise Species Ocean Latitude year tude no. C. chuni Atlantic 63 1 011 S. Skogsberg, 1920 64'04'S. 28 C. elegane Atlantic 550 S. Miller, 1906 67069'S. 17 C. lophura Atlantic 40 0 27 1 S. Skogsberg, 1920 64 0 531 S. 10 C. obtusata Atlantic 63 0 01 1 S. Skogsberg. 1920 67 1 56 1 S. 17 C. rotund ata Indian 65 0 S. Muller, 1906 70007' S. 11 C. 8errulata Indian 59 0 S. Brady, 1907 670561S. 17 C. s y mmetrica Indian 540 S. Muller, 1906 680201 S. 11

the table. However, many of the earlier records were made in the Atlantic, where the Antarctic Convergence is located approximately 10 0 further north than in the Pacific (Mackintosh, 1946). The present author has shown that the Antarctic Convergence inhibits the southern distribution of many pelagic Ostracoda. Because of the systematic coverage of the South Pacific by Eltanin cruises, the distribution of many species that have been incompletely reported by occasional expeditions can now be more precisely determined. C. borealis antipoda, C. serrulata, and C. chuni, for example, have not been found as far north in the South Pacific as in other oceans. The current pattern for the other oceans suggests localized transport of specimens to lower latitudes (e.g., by the Benguela and West Australian Currents) —a movement which does not appear to occur in the Pacific. The antarctic Ostracoda are also represented by both a cosmopolitan species (C. elegans, which is found in the world oceans between 79° N. and 68 0 S.) and a bipolar species (C. borealis, which is represented by a variety in each hemisphere). C. borealis antipoda, the antarctic variety, shares common environmental characteristics with its arctic counterpart, C. borealis maxima. Both are usually found at depths greater than 250 m, at temperatures higher than 0° C., but not normally higher than 7° C. (Jespersen, 1923; Eltanin data) and in salinities greater than 34.00 o/oo. The ontogeny of C. serrulata is also being studied. Over 1,300 specimens from 15 stations across the South Pacific have been measured, including all available instars. Conchoecia develops by molting through seven instars, the last being the adult stage (Claus, 1894). Six instars (two through seven), ranging in size from approximately 300 to 1,700, have been found. The first juvenile instar has not been found, probably because it passes through the 200emesh plankton net. Measurement of the length of the carapace has proved to be a simple technique for designating any particular instar. There is no overlap in length of the progressive instars. This technique may be applicable in differentiating instars of other pelagic Ostracoda if species identification is certain; however, the carapace lengths of different instars within a few Conchoecia species overlap (Fowler, 158

1909), negating any simplified differentiation for all species. References Brady, G. S. 1907. Ostracoda, National Antarctic Expedition, 1901-1904. Natural History, 3(5): 1-9. Claus, C. 1894. Die Halocypriden und ihre Entwicklungs-

stadien. Berichte der Commission für Erforschung der östlichen Mittelmeeres, vol. 61, pt. 3, no. 9.

Fowler, G. H. 1909. Biscayen plankton collected during a cruise of H.M.S. Research, 1900, part 13: The Ostracoda. Linnean Society of London. Transactions, 2(10): 219336. Jespersen, P. 1923. Dr. Thorild Wolff's plankton collection in the waters west of Greenland. Meddelelser om GrØnland, 4: 103-160. Mackintosh, N. A. 1946. The Antarctic Convergence and the distribution of surface temperatures in antarctic waters. Discovery Reports, 23: 177-212. Muller, G. W. 1906. Ostracoda. Wissenschaftlische Ergebnisse der Deutschen Tie fsee Expedition auf dem Damp fer "' Valdivia," 8: 29-154.

Skogsberg, T. 1920. Studies on marine Ostracoda, Part I. Zoologiska Bidrag frãn Uppsala, Suppi. Bd. 1. 784 p.

Texas AM's Biological Productivity Programs Aboard USNS Eltanin and USCGC Glacier SAYED Z. EL-SAYED Department of Oceanography Texas A&M University During the past year, Texas A&M's biologicalproductivity program aboard USNS Eltanin has extended the areas covered in the Pacific Ocean to include the Tasman Sea (Cruise 26), the Ross Sea (Cruise 27), and two crossings of the Pacific—one at latitude 43° S., between Australia and Chile (Cruise 28), and another between Australia and California (Cruise 30). Also, during this period, a biologicalproductivity investigation was conducted aboard USCGC Glacier as part of the International Weddell Sea Oceanographic Expedition (IWSOE). In these investigations, we were interested primarily in assessing the standing crop of phytoplankton and the primary productivity at different depths. We were also interested in studying the species composition and relative abundance of the phytoplankton and in correlating their distribution and abundance with the hydrographic features. Another objective was to assess the role played by the dissolved and particulate organic carbon in the economy of antarctic and subantarctic waters. ANTARCTIC JOURNAL