仿洄游培育美洲鲥亲本的性腺发育

为解决美洲鲥(Alosa sapidissima)人工培育亲本性腺发育不佳的问题,开展了美洲鲥亲本仿洄游的培育,研究观察了美洲鲥亲本卵巢和精巢不同发育阶段(II^V期)的形态特征及相关参数,确定了仿洄游培育美洲鲥亲本性腺初次发育的特征。结果显示:在美洲鲥仿洄游培育过程中,在卵巢、精巢发育前期(II期),雌雄亲本生长迅速;而性腺发育到III期后,雌雄亲本的生长滞缓,雌鱼亲本甚至出现负生长。仿洄游培育美洲鲥性腺初次发育(II^V期)过程中,雌雄亲本均有较高的肥满度,分别为1.55~2.07和1.56~1.71;卵巢发育Ⅴ期雌鱼亲本的肥满度(2.07)显著高于在卵巢II^IV期亲本(1.55~1.67);而雄鱼亲本肥满度在精巢发育各阶段(II^V期)均无显著性差异。仿洄游培育美洲鲥性腺发育良好,雌雄亲本的性腺指数均较高,性腺发育Ⅴ期雌雄亲本的性腺指数(GSI)分别为(26.10±6.46)(18.88~33.62)和(5.18±0.68)(4.49~6.11)。研究表明,仿洄游培育的水温(10.8~30.8℃)和盐度(1~15)的周年变化符合美洲鲥亲本性腺发育的要求。

The gonad development of Alosa sapidissima broodstock cultivated by imitation migration

The imitation migratory cultivation was carried out to solve the problem of gonadal under development in Alosa sapidissima artificially cultured broodstock.The morphological characteristics and related parameters of A.sapidissima broodstock ovaries and testicles at different developmental stages(stageⅡ~Ⅴ)were observed.It was determined that the characteristics of gonad primary development of Alosa sapidissima were cultivated by imitation migration.The results showed that both male and female broodstock grow rapidly in the process of A.sapidissima imitative migratory breeding and in the early development stage of ovary and testicles.Male and female broodstock growth sluggish after to the stageⅢof gonad development,female broodstock appear even negative growth.During the gonad primary development(stageⅡ~Ⅴ)of A.sapidissima was cultivated by imitation migration,both male and female broodstock had higher condition factor as 1.56%~1.71%and 1.55%~2.07%,respectively.The condition factor of female in ovary stage V was significantly higher than that of female in ovarian stageⅡ~Ⅳ.However,there was no significant difference in the condition factor of male broodstock at different developmental testicle stages.After imitation migratory cultivation,the gonads of A.sapidissima were well developed,the gonad indexes(GSI)of male and female broodstock were higher,the GSI of male and female broodstock in the stage V of gonad development were 5.18%±0.68%(4.49%~6.11%)and 26.10%±6.46%(18.88%~33.62%),respectively.According to the study,the annual variation range of water temperature(10.8~30.8℃)and salinity(1~15)of the imitative migratory breeding conforms to the gonad developmental requirements of A.sapidissima broodstock.Therefore,A.sapidissima broodstock was cultivated by imitation migration by low temperature and salinity before,during and after the stage III of the broodstock gonad development.