上海地区长吻（鱼危）全人工繁育技术研究

Study on artificial breeding of Chinese longsnout catfish Leiocassis longirostris in Shanghai

摘要:

为进一步优化长吻（鱼危）的繁育流程,2021—2023年对上海地区池塘养殖3龄及以上长吻（鱼危）成鱼进行了全人工繁育技术研究。单独采用促黄体素释放激素类似物(LHRH-A₂)对长吻（鱼危）亲本进行催产:雌鱼分2次注射,第1针催产剂量为2 μg/kg,第2针剂量为15~20 μg/kg,2针间距12~14 h；雄鱼采用1次注射法,在雌鱼注射第2针的同时进行,注射剂量为雌鱼第2针剂量的一半。3年累计催产雌性亲本230尾,其中成功催产雌性亲鱼186尾,催产率80.9%。受精卵在水温24~26 ℃条件下孵化,于50 h左右开始出膜。出膜仔鱼在室内水泥池静水充气条件下经8~14 d培育,3年累计培育获得体长1 cm以上的苗种21.41万尾。相比以往长吻（鱼危）人工繁殖大多采用野生捕捞亲本,本研究采用人工养殖亲本可确保亲鱼数量和进行质量控制,使用单一催产剂和静水孵化方法简化了过去使用混合催产剂和流水孵化的繁琐操作流程,较易实现规模化繁育。

Abstract:

In order to further optimize the breeding process of Chinese longsnout catfish Leiocassis longirostris,the artificial breeding of pond reared 3-years-old and older L. longirostris in Shanghai were studied from 2021 to 2023 separately.Luteinizing hormone-releasing hormone analogue(LHRH-A₂) was used to induce the spawning of pond reared L. longirostris broodstock.The females were injected twice while males were injected only once.The dose of the first injection was 2 μg/kg fish weight and the second dose was 15-20 μg/kg fish weight, with an interval of 12-14 h between the first and second injection.The male fish were injected when the female was injected the second dose,and the dose was halved.The results showed that 186 of 230 broodstock were successfully spawned after oxytocin injection,with an average spawn rate of 80.9% during the 3 years’ breeding trial.The fertilized eggs hatched at a water temperature of 24-26 ℃,and began to emerge from egg membrane after 50 hours.The hatched larvae were cultured in indoor cement ponds for 8 to 14 days,and a total of 214 100 seedlings with a body length over 1 cm were obtained in 3 years.Compared to the previous artificial breeding of L. longirostris,which mostly relied on wild fishing broodstock,this study used pond raised broodstock to ensure the control of the quantity and quality of the parent fish.The use of a single oxytocin and still water incubation measures simplified the cumbersome operations of mixed oxytocin and flowing water incubation in the past,making it easier to achieve large-scale breeding and providing sufficient supply of seedlings for the breeding of L. longirostris.