Ecological and biological features of a mesopelagic ostracod,Conchoecia pseudodiscophora, in the Japan Sea
Ecological and biological features of a mesopelagic ostracod,Conchoecia pseudodiscophora, in the Japan Sea
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日本海中层介形类Conchoecia pseudodiscophora的生态和生物学特征
DOI：
10.1007/bf01313429
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发表时间：
1990
期刊：
影响因子：
2.4
通讯作者：
T. Ikeda
中科院分区：
文献类型：
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作者：
T. Ikeda
1985年、1987年和1989年在日本海调查了一种盐驱类介形类甲壳纲（Conchoecia pseudodiscophora）的丰度和垂直分布格局。在大和洋面附近500 m深度至水面的垂直取样表明，在0.35 mm网目Norpac采集的浮游动物总数中，该介形虫的数量居第二位，生物量居第三至第四位。富山湾的水平网拖表明，c。pseudodiscophora分布在250 ~ 300 m深度以下。无明显的昼夜迁移模式。在生物量方面，它对总浮游动物的贡献为5%至10%或更多。根据0.10 mm网目Norpac采集标本的大小和形态特征，鉴定出5只亚成虫（II ~ VI）和雌雄成虫。给出了每只星的体长、湿重和干重数据。选取4 ~ 6期（亚成虫4 ~ 6期，雌成虫）的鲜、冻干标本，碳含量为干重的35 ~ 48%，氮含量为干重的5.3 ~ 7.3%。这4个龄期混合试样的含水量和灰分含量分别为湿重的76%和干重的25%。c实验室维护的可行性。经检测，它产生特征性的“J”形粪便颗粒。亚成虫V、VI和成年雌虫的耗氧率为0.011 ~ 0.021µl O2ind。在1°C下，或2.9 ~ 6.1µl O2(mg body N) - 0.85h - 1，以调节代谢率（AMRo2）计算。与其他介形类动物相比，尽管它们的生活方式是中远洋的，但它们的代谢没有明显的减少。总浮游动物的亚优势和c的非降低代谢活性。pseudodiscophorasa表明该物种可能是日本海中上层能量流动和物质循环的重要环节。
The abundance and vertical distribution pattern of a halocyprid ostracod,Conchoecia pseudodiscophora, were investigated in the Japan Sea in 1985, 1987 and 1989. Vertical sampling from 500 m depth to the surface in the water around Yamato Rise revealed that this ostracod was second in dominance by number and third to fourth by biomass of the total zooplankton collected with a 0.35 mm mesh Norpac net. Horizontal net tows in Toyama Bay indicated that the major population ofC. pseudodiscophorawas distributed below 250 to 300 m depth. No diel migration pattern was evident. Its contribution to total zooplankton there was 5 to 10% or more in terms of biomass. A total of five subadult instars (II to VI) and adult males and females were identified from instar analysis based on sizes and morphological characteristics of specimens collected with 0.10 mm mesh Norpac nets. Data on body length, wet weight and dry weight of each instar are presented. Carbon content of 35 to 48% of dry weight, and nitrogen content of 5.3 to 7.3% of dry weight, were recorded on fresh, freeze-dried specimens of selected instars (subadult Instars IV to VI, adult females). Water and ash contents of mixed specimens of these four instars were 76% of wet weight and 25% of dry weight, respectively. Feasibility of laboratory maintenance ofC. pseudodiscophorawas tested, and it produced characteristic “J” shaped faecal pellets. Oxygen consumption rates of subadult instars V and VI, and adult female ranged 0.011 to 0.021µl O2ind.−1h−1at 1 °C, or 2.9 to 6.1µl O2(mg body N)−0.85h−1in terms of Adjusted Metabolic Rate (AMRo2). There was no appreciable metabolic reduction inC. pseudodiscophoracompared to other ostracods, despite their mesopelagic life mode. Subdominance in total zooplankton and nonreduced metabolic activity ofC. pseudodiscophorasuggest that this species may be an important link in mesopelagic energy-flow and matter cycling in the Japan Sea.