养殖施氏鲟的人工繁殖

Artificial reproduction of cultured Acipenser schenckii

对6尾雌性养殖施氏鲟(AcipenserschrenckiiBrandt)进行人工催产,其中4尾雌鲟顺利排卵;采用输卵管切割手术取卵,获成熟卵7.7kg,共计42.77×104粒;以"半干法"授精,获受精卵28.82×104粒,受精率67.37%;孵出鱼苗12.69×104尾,孵化率43.63%。本研究对人工催情方法和活体取卵方法与手术技巧进行分析,结果发现,人工养殖亲鱼催产效应时间长于野生鱼(已报道);不同时间取出鱼卵的授精效果差异较大,即成熟卵均能受精,但受精率随产卵时间的延长而逐渐降低;经产雄鱼与初产雄鱼间精子活力差异显著,经产雄鱼精子平均快速泳动时间及精子寿命均长于初产雄鱼精子。

Six female Acipenser schrenckii, of which the eggs maturation was at stage Ⅳ and total length was 142157 cm, were injected by external hormone LHRHA2 to induce them to spawn. Meanwhile, 20 adult male A. schrenckii were injected with external hormone LHRHA2. Four of the six females reproduced 427.7 thousand eggs by surgery (cutting oviduct), and the total eggs weighted 7.7 kg. Artificial fertilization was conducted by halfdrying method and the fertilization rate was 67.3% , and 126.9 thousand larvae were hatched, hatching rate 43.63%. During the experiment, the six females had spawning reaction at 33rd- 44th hour after the injection with LHRHA2, which implicated that the effect time of external hormone treatment on cultured fish was longer than that on wild fish (reported previously).By different ways of getting eggs (by stomach cutting (reported previously), oviduct cutting and squeezing), the fertilization rate was much different that by squeezing, most mature eggs could not be collected; by the first two methods, most of the mature eggs could be collected, but the former was more complex in operation and the conducting time was lasted which would led to the decrease of fertilizing rate. For the adult males, the spermatozoa vitality was different between the first time and second time of spawning that the secondtimespawned eggs had longer time of motility than the firsttimespawned eggs.