金沙江下游中华沙鳅的资源现状、繁殖特性及人工繁育的初步研究

2011年5～12月,对金沙江屏山以下江段中华沙鳅(Botia superciliaris)的资源现状、繁殖特性进行了调查,并在实验室对该鱼的人工繁育进行了探索。所获中华沙鳅雄鱼(n=251)平均体长81.3 mm,平均体重8.7 g;雌鱼(n=486)平均体长109.7 mm,平均体重15.9 g。屏山调查点中华沙鳅占总渔获物(尾数)的2.68%,日均单船产量平均为0.12 kg;安边调查点中华沙鳅占总渔获物(尾数)的0.17%,日均单船产量平均为0.06 kg。雌雄性比为1.31∶1;雌、雄最小性成熟年龄均为2+龄。雌鱼的绝对怀卵量最大值为5 948粒,平均为4 455粒。中华沙鳅属一次性产卵类型,在流水中产漂流性卵;繁殖高峰期在5～6月。人工繁育时,受精卵在水温25～26℃孵化29 h仔鱼出膜,孵化率约70%,刚出膜仔鱼全长4.9～5.1 mm。半年后幼鱼的成活率为11.13%,全长约30 mm。

A preliminary study on the existing state of resources, reproductive feature and artificial breeding of Botia superciliaris in the lower reaches of the Jinsha River

A preliminary study on the existing state of resources,reproductive feature and artificial breeding of Botia superciliaris in the lower reaches of the Jinsha River was carried out from May to December in 2011.The mean length of the male caught fish was 81.3 mm(n=251),mean weight was 8.7 g.The mean length of the female caught fish was 109.7 mm(n=486),mean weight was 15.9 g.B.superciliaris occapied 2.68% of the catches in Pin Shan and 0.17% of the catches An-Bian.The mean daily catches per boat of B.superciliaris in Pin-Shan and in An-Bian were 0.12 kg and 0.06 kg.The female-male ratio was 1.31∶ 1.It is sex gland matured in the 2+ years old both of female and male.The largest value of absolute fecundity was 5 948 eggs/ fish and the mean value was 4 455 eggs/ fish.It was a kind of fish with floating eggs and one-off spawning stage.The peak period of spawning was May to June.The larvae hatched out in 29 h after fertilization at water temperature of 25~26 ℃ and the hatching rate was 70%.The newly hatched larvae had total body length ranging from 4.9 mm to 5.1 mm.The survival rate of young fish was 11.13% after half a year and the total body length was 30 mm.