徐家河水库近太湖新银鱼繁殖生物学研究

近太湖新银鱼个体虽小 ,生命周期只有 1年 ,但它却在湖北省徐家河水库成为最大的鱼类优势种群 ,形成较大的生产量 ,这是它所具有的独特生物学特性而决定的。经过多年研究 ,特别是通过对1 995年 5月至 1 996年 4月每月采的近太湖新银鱼的样本分析和研究发现 ,与同时生活在该水库的其它硬骨鱼类相比 ,近太湖新银鱼在繁殖方面表现出广泛的繁殖策略。主要表现为 :生殖腺成熟发育时间短 ,完成卵黄沉积的大生长期只需 50d左右 ;繁殖季节早 ,最早的繁殖时间为每年的 2～ 3月 ,繁殖高峰期为 4月中旬 ;繁殖力高 ,单位体重的怀卵量高出该水库其它鱼类 ,平均相对怀卵量为 4 40～ 1 2 2 3粒 /g ;繁殖周期短 ,仔鱼孵出后经过 1 0月即可成熟产卵

Reproductive Biology of Icefish ( Neosalanx pseudotaihuensis Zhang)in Xujiahe Reservoir

Samples collected monthly from Xujiahe Reservoir between May 1995 and April 1996 were used to elucidate various aspects of the reproductive biology of Neosalanx pseudotaihuensis in this reservoir. The maximum gonadosomatic index (GSI) occurred in April with a mean value of 18.40%. The maximum diameter of oocytes appeared also in April with a mean value of 0.59 mm. N. pseudotaihuensis spawns between March and May with spawning activity peaking in the middle of April, and as the new recruits enter the population, the old generation disappears. The success of N. pseudotaihuensis in Xujiahe Reservoir attributes partial to its production of very large numbers of eggs at each time when conditions in the reservoir are relatively stable. This species N. pseudotashuensis exhibit a wide range of reproductive strategies, compared to other indigenous teleosts.