哲罗鱼的产卵量和亲鱼死亡分析

Fecundity and Death Reasons after Spawning in Broodstock Hucho taimen(Pallas)

统计分析了2008～2012年期间哲罗鱼雌亲鱼产前、产后体质量和产卵量及人工繁殖中产后亲鱼死亡的原因。结果表明,在繁殖期雌性亲鱼的体长与产前体质量相关性符合幂函数方程W=0.003L3.326,R2=0.926;产前个体之间体质量与实际的产卵量关系差异性较大,有的产前体质量较小,产卵量却较高,有的产前体质量较大,产卵量却较少,但整体趋势随着产前体质量的增大,产卵量增多。初次性成熟的个体产卵量一般在3116±1054粒,随着年龄和体质量的增加,产卵量逐渐增多,10kg的个体产卵量可达到17361±5304粒。人工繁殖过程中,亲鱼死亡的原因多数是人工操作不当,体表受伤水霉滋生而致死,少数个体是由于背部注射药物造成肌肉腐烂及体内血管破裂造成大出血而死亡,并针对亲鱼产后死亡的情况提出了预防措施。

The female body weight ofbroodstock before and after spawning, and fecundity were measured and the reasons for death af- ter artificial reproduction were evaluated in Hucho taimen （Pallas） from 2008 to 2012. The results showed that the regression relation- ship between body length and body weight of the female broodstock before spawning was described as power function equation： W=0.003L3326, R2=-0.926 during the breeding period. There was variation in relationship between body weight of the female broodstock before spawning and fecundity of the female, some lighter individuals having higher fecundity and vice versa. However, higher fecun- dity was mostly derived from the larger individuals in general. The first maturity individuals had fecundity of some 3116± 1054 eggs, increase with the increase in age and body weight, and 17361±5304 of eggs by the individual with body weight of 10 kg. The brood- stock death was most involved in Saprolegnia infection in the wound caused by improper handling, or in rotted muscles due to injec- tion in the back and in haemorrhage caused by angiorrhexis in vivo during the artificial breeding. Several suggestions are made for im- provement of broodstock survival after spawning.