Food restriction is part of the life cycle of many fish species; however, nutritional deficiency may negatively influence gametogenesis and gonadal maturation. The aim of this study was to evaluate the effects of food restriction on the spermatogenesis of Nile tilapia. For this, adult males were submitted to starvation and refeeding cycles (alternating periods of starvation and feeding) for 7, 14, 21, and 28 days. After 7 days of starvation, glycaemic and lipid levels were significantly reduced, followed by reduction of plasma testosterone (T) and 11-ketotestosterone (11-KT). In addition, reduced proliferation of spermatogonia and increased apoptosis of spermatocytes, spermatids, and spermatozoa was observed in starvation groups. In the refeeding groups, the sex steroids and the proportion of germ cells had no significant alterations compared to the control group, except for spermatozoa. In this sense, the present study suggests that starvation after 7 days progressively reduces T and 11-TK, resulting in damage to the production of spermatogenic cells, while refeeding may delay spermatogenesis but does not lead to testicular impairment.

中文翻译：

---

饥饿和补饲周期对尼罗罗非鱼尼罗罗非鱼精子发生和性类固醇的影响。

食物限制是许多鱼类生命周期的一部分；但是，营养不足可能会对配子发生和性腺成熟产生负面影响。这项研究的目的是评估食物限制对尼罗罗非鱼精子发生的影响。为此，成年雄性被置于饥饿和重新喂养周期（饥饿和喂养的交替时期）7、14、21和28天。饥饿7天后，血糖和脂质水平显着降低，随后血浆睾酮（T）和11-酮睾酮（11-KT）降低。此外，在饥饿组中观察到精原细胞增殖减少，精细胞，精子和精子凋亡增加。在补饲组中，除精子外，性类固醇和生殖细胞比例与对照组相比无明显变化。从这个意义上说，本研究表明，饥饿7天后会逐渐降低T和11-TK，从而导致生精细胞产生损伤，而重新喂养可能会延迟生精，但不会导致睾丸损伤。