嘉陵江梯级水利工程开发下不同江段蛇鮈的繁殖生物学特性差异及适应

2015年1-12月(除2-4月外)在嘉陵江不同江段(上、中、下游)采集蛇鮈(Saurogobio dabryi)样本,进行繁殖生物学比较研究。结果显示:嘉陵江蛇鮈的最小性成熟年龄均为1^+龄,性比接近1∶1,且在不同江段间无显著性差异;不同江段蛇鮈的最小性成熟规格存在一定差异,其中,上游、中游最小性成熟个体体长、体重均无显著差异,但都显著大于下游蛇鮈;上、中、下游的蛇鮈繁殖期分别为2-6月、2-5月、2-4月;蛇鮈绝对生殖力和相对体长生殖力的变化趋势均为上游>下游>中游,相对体重生殖力的变化趋势为下游>上游>中游,卵径大小变化趋势为:中游>上游>下游。

Difference and adaptation of reproductive biological characteristics of Saurogobio dabryi in Jialing River cascade water conservancy project

Samples of Saurogobio dabryi were collected from different reaches from January to December, 2015 ( except February to April) to research and compare reproductive characteristics of this speciesin different reaches in Jialing River. The results showed that the first sex-maturity age of female and male individuals were both 1 + age, the sex ratio ( female:male) was closed to 1∶ 1. There was no significant difference for the first sex-maturity age and the sex ratioin different reaches. However, there were some differences between the minimum mature specifications of S. dabryi , the length and weight of the smallest mature individuals in the upper and middle reaches were significant bigger than that in the downstream, and there was no significant difference for same specifications of the smallest mature individuals between the upper and middle reaches. The breeding season of S.dabryi in the upper, middle and downstream reaches were February to June, February to May and February to April, respectively. The changed trend of S.dabryi of absolute fecundity and relative body length fecundity from high to low were the downstream reaches, middle reaches, upper reaches. While the change trends of the relative body weight from high to low were the upper reaches, downstream reaches, the middle stream reaches. The changed trends of egg diameter from big to small were the midstream reaches, the upper reaches, the downstream reachesunder the development of Cascade water conservancy projects in Jialing River.