东海浮游糠虾类生态类型划分及其对水团的指示作用

Pelagic Mysidacea in East China Sea and its significance as the indicator of water mass

根据1997-2000年东海23°30′-33°N、118°30′-128°E海域4个季节海洋调查资料,对浮游糠虾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,计算糠虾类分布的最适温度和盐度,分析其地理分布和季节分布特征,确定物种的生态类型.结果表明:宽尾刺糠虾(Acanthomysis latiscauda)、漂浮囊糠虾(Gastrosaccus pelagicus)、中华节糠虾(Siriel-la sinensis)和美丽拟节糠虾(Hemisiriella pulchra)是亚热带近海种,同时具有暖温种的特征;极小假近糠虾(Pseudanchialina pusilla)、东方原糠虾(Promysis orientalis)、小红糠虾(Erythropsminuta)和双眼准异糠虾(Anisomysis bipartoculata)虽是亚热带外海种,但具有热带大洋种特征.东海浮游糠虾类大多数物种的最适温、盐度偏低,冬春季在东海近海有更多的分布,因而具有暖温近海类型的生物学特征,这是该类浮游动物区别于其它浮游动物类群的重要特征.宽尾刺糠虾、中华节糠虾和美丽拟节糠虾的较高丰度区,也正是长江冲淡水与暖流水团交汇、沿岸水团与外海高盐水团交汇的位置.小红糠虾和双眼准异糠虾可作为暖流指示种.四刺端糠虾(Doxomysis quadrispinosa)和东方原糠虾是台湾暖流指示种.其它种均不是良好的水团指示种.

Based on the investigation data of four seasonal oceanographic censuses in the area 23°30′ -33°N and 118°30′- 128°E of East China Sea in 1997-2000, this paper studied the ecotypes and geographic and seasonal distribution of pelagic Mysidacea in this sea area, with its significance as the indicator of water mass approached. The results showed that among the species of pelagic Mysidacea, Acanthomysis latiscauda, Gastrosaccus pelagicus, Siriella sinensis and Hemisiriella pulchra were the coastal subtropical species with some features of warm temperate species, while Pseudanchialina pusilla, Promysis orientalis, Erythrops minuta and Anisomysis bipartoculata were the offshore subtropical species with some features of tropical species. Different from other zooplanktons, most of the pelagic Mysidacea species had lower optimal temperature and salinity anddistributed more at near-shore in spring and winter, showing the features of warm temperate near-shore species. The areas with high abundance of A. latiscauda, S. sinensis and H. pulchra were just the converging areas of the Changjiang dilute waters and warm current masses and of coastal waters and offshore high salinity waters. Erythrops minuta and Anisomysis bipartoculata could be used as the in- dicators of warm current, P. orientalis and Doxomysis quadrispinosa were the indicators of the Taiwan warm current, while the rest were not good enough to be the indicators of water masses.