长江口及其邻近海区主要经济虾类的生态研究

本文主要取材于1985—1986年长江口渔业资源试捕调查资料。研究结果表明,分布在长江口海区的虾类,由于受长江冲淡水径流的影响,形成三种生态型:(1)河口半咸水类型,如两种白虾;(2)低盐水类型,如葛氏长臂虾;(3)外侧次高盐水类型,如鹰爪虾和两种仿对虾。代表各生态型虾类,一般具有繁殖期较长的特点,其生命周期可为一年或一年多。虾类体长分布较为复杂,在当年生的幼虾生长期间,秋冬季虾群中常有幼虾和成虾混栖。因而,种群体长分布有两组群体并存。

AN INVESTIGATION ON THE ECOLOGY OF ECONOMIC IMPORTANT SHRIMP IN THE CHANGJIANG RIVER ESTUARY AND ITS ADJACENT SEA

Changjiang river estuary and its adjacent sea is a low salinity environment, due to the affect of freshwater input from Changjiang River. The three ecological types of the shrimp are formed there, which are brackish, low salinity and high salinity types.The main reproduction period of the shrimp in the area is between May to June. The shrimps of the three ecological types show separate reproductive characteristics.The ranges of body lengths of 6 shrimp species are 15-50mm for Exopalaemon annandalei, 20-80mm E. carinicauda, 25-75mm for palaemon gravieri, 35-100mm for Trachypenaeus curvirostris 35-100mm for females and 35-75mm for males of Trachypenaeus curvirostris, Parapenaeopsis cultrirostris and P. hardwickii and 35-105mm for females and 35-80mm for males of Parapenaeopsis cultrirostris and P. hardwickii respectively. In September, the juvenile with a few adults are migrating together. The body length distributions of these shrimps show that they have generally two stock compositions.