东海浮游糠虾种类特征和多样性

依据1997～2000年对东海23°30′～33°00′N、118°30′～128°00′E海域4个季节海洋调查资料，运用定量、定性方法, 探讨了东海浮游糠虾类种类特征、多样性以及种类分布与环境的关系.结果显示，东海调查水域共鉴定浮游糠虾类18种，秋季最多，有14种，夏季9种，春季7种，冬季仅4种；漂浮囊糠虾（Gastrosaccus pelagicus）等11个种是东海的常见种，东方原糠虾（Hypererythrops spinifera）是次常见种，其余则是稀有种；糠虾类物种的季节更替十分明显,特别是从秋季到冬季；盐度是影响东海糠虾类分布的主要环境因子，冬、夏季，糠虾类分布主要受沿岸河流和长江径流的影响，物种数与盐度呈负相关，秋季物种数与表层温度呈负相关，与底层盐度呈正相关.东海糠虾种类组成季节特征和地区特征的形成主要与长江径流势力消长有关.东海各海区糠虾类多样性指数（H′）值大多数较低，与其主要优势种的聚集性有关.

Species characteristics and diversity of pelagic Mysidacea in East China Sea

Based on the investigation data of four oceanographic cruises in the East China Sea (23 degrees 30' - 33 degrees 00' N, 118 degrees 30' - 128 degrees 00') in 1997-2000, this paper studied the species characteristics and diversity of mysids, and the relationships between its species number and environmental factors. A total of 18 mysids species were observed, with 14 species occurred in autumn, 9 species occurred in summer, 7 species occurred in spring, and 4 species occurred in winter. The species composition showed a clear seasonal alternation, especially from autumn to winter. Seawater salinity was the main environmental factor affecting the distribution of the mysids. In summer and winter, mysids distribution was mainly affected by the runoff from continental rivers, and species number had a significant negative correlation with seawater salinity, while in autumn, the species number had a negative correlation with surface seawater temperature but a positive correlation with bottom seawater salinity. The spatial-temporal variation of mysids geographical distribution was linked with the ebb and flow of the Changjiang River, and the dominant species of mysids tended to agglomerate, which was the major reason of the low diversity of mysids in the East China Sea.