长江口刀鲚洄游群体生殖特征和条件状况研究

Reproductive characteristics and conditions of anadromous Coilia ectenes(Engraulidae) in Yangtze Estuary

为探求长江口地区溯河群体刀鲚生殖特征和条件状况，于2006—2008年刀鲚溯河洄游期间，采集刀鲚样品。通过对其体长、体重、肝重、性腺重、条件指数、脂肪重等生物学参数的研究，以了解三年内溯河群体刀鲚的生殖特征和条件状况的变化。研究结果表明：（1）洄游群体刀鲚体长、体重年际间有变化，体长一体重的拟合关系年际间有差异。（2）长江口地区涸游群体刀鲚生殖特征年际间有变化，刀鲚性腺重量与体长、体重关系密切，均呈正相关关系。（3）洄游群体刀鲚条件状况，不同年份亦有变化。其中：肝重、脂肪重分别与体长、体重关系密切，呈正相关；洄游群体刀鲚条件指数2007年最大，对每个年份刀鲚条件指数进一步分析，显示：随着年龄的增加，刀鲚的条件指数逐渐增加，由1龄到2龄，条件指数变化最大（P〈0．01）。综上所述，洄游群体刀鲚生殖特征和条件状况的动态变化，显示了气候对洄游群体刀鲚生殖状况影响的动态过程。

To survey the reproductive characteristics and conditions of the stock of spawning migration Coilia ectenes in Yangtze Estuary, C. ectenes samples were collected during the spawning migration periods from 2006 to 2008. To understand the reproduction status of the C. ectenes, some biological parameters were analyzed, such as body-length, body-weight, hepatosomatie-weight, gonad-weight, fat-weight and condition factor. The results revealed： （1） The body-length and body-weight changed in different years, and the relationship between body-length and body-weight showed variations in three years. （2） The reproductive characteristics of spawning migration C. ectenes varied in different years, and positive correlation between gonad-weight and both body-length and body-weight were found. （3） The condition factor of spawning migration C. ectenes changed in different years, and positive correlation between the liver-weight or lipid- weight and the body-length or body-weight were detected; the condition factor in 2007 was higher than that of other years, and the condition factor of spawning migration C. ectenes increased with the fish age, which showed the biggest changes between 1 and 2-year-old-ones （P 〈 0. 01 ）. In summary, the reproductive characteristics and condition variations of spawning migration C. ectenes indicated the processes of how the climate impacted the reproductive status of anadromous fish.