Пелагические остракоды рода Discoconchoecia (Ostracoda-Halocyprididae) северной части Тихого океана

• Main Authors: Чавтур, В., Стовбун, Г.
• Format: Text
• Language: unknown
• Published: Федеральное государственное унитарное предприятие «Тихоокеанский научно-исследовательский рыбохозяйственный центр» 2004
• Subjects: Okhotsk; Pacific; Subarctic
• Online Access: http://cyberleninka.ru/article/n/pelagicheskie-ostrakody-roda-discoconchoecia-ostracoda-halocyprididae-severnoy-chasti-tihogo-okeana; http://cyberleninka.ru/article_covers/13175557.png

Изучены материалы по остракодам многочисленных российских экспедиций в северной Пацифике (севернее 300 с.ш.). Дана картина пространственного распределения видов рода Discoconchoecia (D. pseudodiscophora, D. discophora discophora и D. elegans elegans) в условиях вод субарктической и субтропической структур в диапазоне глубин 0-4000 м. Приведены определительная таблица, иллюстрации дифференциальных признаков и данные о распространении этих видов. Extensive plankton materials on pelagic ostracods of the genus Discoconchoecia collected by numerous Russian expeditions during 1927-1990 from temperate zone of the North Pacific and adjacent subtropical waters (northward from 300 N) in the depth range 0-4000 m have been examined. Three species belonging to the genus were identified in this area: D. pseudodiscophora (Rudjakov, 1962), D. elegans elegans (Sars, 1865), and D. discophora discophora (Mьller, 1906). The key to these species definition and their figures are presented. Their geographical and vertical distribution is described in detail. In the North-West Pacific, D. pseudodiscophora is widely distributed in the area between 330 and 620 N (including the Japan, Okhotsk and Bering Seas) at the depth range 0-4000 m. Its number and biomass is the highest at the depth 200-300 m. The species is 90-95 % of the total halocyprid population in 0-300 m layer, with the highest values of relative biomass (70 % and 75 %) in 0-50 and 200-300 m layers. In the North-East Pacific, this species occurs between 470 and 590 N at the depth range 50-2000 m, with a considerably less abundance and biomass (up to 50 % of the total halocyprids number and 15 % of their total biomass in the layer 100-200 m). Its maximal abundance is here in 200-300 m layer, as well. The species belongs to the boreal, oceanic and interzonal plankton group and is the indicator of the waters of subarctic structure in the Pacific. D. elegans elegans inhabits subtropical zone of the North-West Pacific, at the depth range 0-4000 m, where it is the most abundant in the layer 100-200 m. In the North-Eastern Pacific this subspecies has been found in subarctic and subtropical waters between 300 and 590 N. Its vertical distribution has been studied in the Aleutian Trench, where D. elegans elegans occurs at 100-2000 m. Both its number and biomass were the greatest at 200-300 m and declined steadily downward. The contribution of this subspecies to the total halocyprid populations is very small; the maximum relative abundance is about 10 % and relative biomass is 3 % at the layer 200-300 m. Only few specimens of D. discophora discophora were found on three stations in the area 56015'-56046' N and 136-1390 W at depth range 1500-2500 m.