丹江口水库太湖新银鱼不同繁殖群体的繁殖特征比较

2010年6月—2011年6月,对丹江口水库太湖新银鱼(Neosalanx taihuensis)不同繁殖群体的繁殖生物学特征进行了比较研究。结果表明:太湖新银鱼在该水库产卵时间为1—5月(春群)和9—10月(秋群);其中春季群体的体长(65.79 mm±6.05 mm)、性腺成熟指数(17.26±6.42)、繁殖力(1851粒±342粒)和成熟卵径(0.62 mm±0.05mm)均显著高于秋季群体(体长(55.04 mm±3.18 mm)、性腺成熟指数(11.72±5.01)、繁殖力(1 067粒±190粒)和成熟卵径(0.53 mm±0.04 mm))(P<0.05);但是两个群体的丰满度指数(101.43±19.71,101.87±11.85)差异并不显著(P>0.05)。春群是丹江口水库太湖新银鱼种群的主要补充者,春群管理与控制应是银鱼种群管理的重点。

A comparative study on reproductive characteristics of different spawning stocks of the icefish(Neosalanx taihuensis) in the Danjiangkou Reservoir

From June 2010 to June 2011,a comparative study on the reproductive characteristics of two spawning stocks of the icefish Neosalanx taihuensis in the Danjiangkou Reservoir was conducted.The results indicated that the spawning seasons of the icefish in the reservoir were from January to May(Spring spawning stock) and from September to October(Autumn spawning stock).The standard length(65.79±6.05 mm),gonadal maturation index(17.26±6.42),absolute fecundity(1 851±342 ind) and oocyte diameter(0.62±0.05 mm) of the spring spawning stock in the reservoir were significantly higher than those of the autumn spawning stock the standard length(55.04±3.18 mm),gonadal maturation index(11.72±5.01),absolute fecundity(1067±190 ind),and oocyte diameter(0.53±0.04 mm),respectively.But there were no significant differences in relative condition factor between the two stocks(P>0.05).The spring spawning stock was the main recruitment population of the icefish in the Danjiangkou Reservoir.More attention should be paid to the management and control of the spring stock of the icefish population.