大口鲇苗种规模化繁育的关键技术

Key techniques of large scale artificial breeding of Silurus meridionalis larvae

研究了大口鲇规模化人工繁殖和苗种培育的关键技术。结果表明 ,在水温 19～ 2 5℃下 ,采用HCG +PG +LRH -A2 和催产灵 1号 +LRH -A2 这 2种混合催产药物对大口鲇催产都十分有效 ,催产率均为 10 0 % ;鱼卵受精率与人工授精方式有着密切的关系 ;鱼苗开口时间和饵料丰欠对苗种培育成活率影响显著 ,饵料缺乏是导致苗种培育成活率降低的主要原因。对 92 0万尾大口鲇水花鱼苗进行了规模化培育 ,共培育 3cm以上规格苗种 74 2 .2万尾 ,平均育苗成活率为 80 .6 7%。

This paper deals with key techniques of large scale artificial propagation and breeding of S.meridionalis larvae.The results indicated that it was quite effective to induce spawning for female S.meridionalis by mesns of two kinds of mixed oxytocic hormones.The two kinds of mixed oxytocic hormones were (HCG+PG+LRH-A 2) and (oxytocic efficaciousness +LRH-A 2) .HCG is human chorionic gonadotrophin,PG is pituitary gland of Cyprinus carpio L.,and LRH-A 2 is luleinizing hormone releasing homone analogue.Their rates to induce spawning were 100%.The fertilization rate of eggs had close relationship with artificial fertilizing methods.The survial rates of larvae breeding were affected remarkably by opening mouth times of fries and sufficient or insufficient diets.The experiment showed that the fittest period of opening mouth of fries was from an hour before yolk sac disappearing to an hour after yolk sac disappearing completely.The main reason of survial rate decreasing on larvae breeding was caused by insufficient diet.The individuals of breeding larvae over 3 centimeter was 7.422 million individuals and the average survial rate was 80.67% when 9.2 million inidviduals of S.meridionalis fries were bred.