Growth hormone on ovarian morphology of lambaris (Astyanax bimaculatus) after induced spawning

ABSTRACT: Lambari, Astyanax bimaculatus, is an oviparous, multiple-spawning fish that is reproductively active throughout the year, which makes it promising for cultivation and research. This research histologically evaluates the ovaries of lambari that have undergone artificial spawning induced with pituitary extract (control group), and the effect of growth hormone at a dose of 2 mg/g body weight (treatment group) on the subsequent process of ovarian recovery. Ovaries of fish in both the control and treatments groups were collected at 120 hours after spawning and analyzed using optical microscopy to characterize the average quantities of: follicles in different stages of development, post-ovulatory follicles, follicular atresia and granulocytes. Quantity and morphology of early and advanced primary follicles did not differ between the treatment and control groups; an important and necessary factor for ovarian recovery for subsequent spawning. There was a greater amount of granulocytes in initial atresia in the group treated with growth hormone. These results demonstrated that the administration of growth hormone may potentiate the process of ovarian recovery after induced spawning.

摘要：拉巴里鱼（Lambari，*Astyanax bimaculatus*）是一种卵生、多次产卵的鱼类，全年均可维持繁殖活性，极具养殖与研究价值。本研究采用组织学方法，对经垂体提取物诱导人工产卵的拉巴里鱼卵巢（对照组）进行评估，并探究剂量为2 mg/g体重的生长激素（growth hormone）处理组对其产卵后卵巢恢复过程的影响。两组实验鱼均于产卵后120小时采集卵巢，通过光学显微镜开展分析，以定量分析不同发育阶段卵泡、排卵后滤泡、卵泡闭锁情况及粒细胞的平均水平。结果显示，处理组与对照组的早期及晚期初级卵泡的数量与形态均无显著差异，这一指标对于保障后续产卵所需的卵巢恢复而言至关重要。生长激素处理组在卵泡初始闭锁阶段的粒细胞数量显著更高。上述结果表明，施加生长激素可有效促进人工诱导产卵后的卵巢恢复进程。