东海浮游枝角类和涟虫类生态适应性

Ecological adaptation of pelagic Cladocera and Cumacea in East China Sea

根据1997-2000年东海23°30′-33°00′N、118°30′-128°00′E海域4个季节海洋综合调查资料,以及2002-2003年长江口外海29°00′-32°00′N、122°00′-123°30′E海域4个季节资料,对浮游枝角类、涟虫类丰度和同步的表层温、盐度数据进行曲线拟合,构造数学模型,计算各物种分布的最适温度和盐度,分析其地理分布和生态特征,确定物种的生态类型。结果表明:鸟喙尖头溞(Penilia avirostris)、肥胖三角溞(Evadne tergestina)是亚热带近海种,具有广温广盐的生态特征;诺氏三角溞(Evadne nordmanni)、萨氏异涟虫(Heterocumasarst)和细长涟虫(Iphinoe tenera)是亚热带外海种,其中诺氏三角溞具有暖温种的特征,后两种涟虫(Bodotria ovalis)是典型的亚热带外海种;卵圆涟虫仅仅在长江口近海出现,是亚热带近海种。东海浮游枝角类大多数物种最适盐度偏低,尤其是鸟喙尖头溞和肥胖三角溞,它们的高丰度分布区是沿岸水团的标志。

Based on the data of four seasonal oceanographic investigations in the East China Sea （23°30＇-33°00＇N, 118°30＇-128°00＇E） in 1997-2000 and off the waters of the Changjiang Estuary （29°00-32°00＇N, 122°00＇-123°30＇E） in 2002-2003, the environmental adaptation and ecotypes of pelagic Cladocera and Cumacea were studied by the methods of fitting curves between species abundance and surface water temperature or salinity, forming mathematical models, calculating optimal temperature and salinity, analyzing species geographic distribution, and determining ecotypes. The results showed that Penilia avirostris and Evadne tergestina were the coastal subtropical water species with eurythermal and euryhalinous characters; E. nordmanni, Heterocuma sarsi and Iphinoe tenera were defined as offshore subtropical water species, among which, E. nordmanni was characterized by some features of temperate water species, while the other two were typical offshore subtropical water species; and Bodotria ovalis only appeared in the sea near Changjiang Estuary, being a coastal subtropical water species. The low water salinity was suitable for most of marine Cladocera species, especially P. avirostris and E. tergestina, and thus, the high abundance of P. avirostris and E. tergestina were the signs of coastal water mass.