Melillo Filho Reinaldo, Bazzoli Nilo, de Souza E Silva Walisson, Costa Deliane Cristina, Boaventura Túlio Pacheco, da Costa Julio Gustavo Soares, Luz Ronald Kennedy
Universidade Federal de Minas Gerais, Escola de veterinária, Departamento de Zootecnia, Laboratório de Aquacultura, Avenida Antônio Carlos, 6627, CEP 30161-970, Brazil.
Pontifícia Universidade Católica de Minas Gerais, Avenida Dom José Gaspar 500, Coração Eucarístico, Caixa Postal 1686, CEP 30535-610, Brazil.
Anim Reprod Sci. 2020 Mar;214:106311. doi: 10.1016/j.anireprosci.2020.106311. Epub 2020 Feb 6.
Lophiosilurus alexandri is a freshwater carnivorous fish for which there is fishing pressure in its natural environment, yet the species has potential for captive rearing. Information on growth and sexual development for the species is scarce, and age and size at first maturation have yet to be determined. A total of 400 fish, therefore, were reared from hatching to 968 days after hatching (DAH). Fish gonads were histologically analyzed throughout the rearing period, and growth, the hepatosomatic index and the gonadosomatic index were compared between males and females. Estradiol, testosterone and 17α-hydroxyprogesterone concentrations were quantified at 845 and 968 DAH to compare sexually mature males and females. Weight and length did not differ between males and females (P > 0.05). Males were sexually mature at 593 DAH, with body lengths of 29.88 ± 1.76 cm and weights of 444.1 ± 77.03 g, while females were sexually mature at 845 DAH, with lengths of 36.51 ± 1.06 cm and body weights of 783.05 ± 48.57 g. The results provided important information regarding the minimum capture size of L. alexandri for identifying the appropriate period to begin reproductive management of the species.
亚历山大低冠鲶是一种淡水肉食性鱼类，其天然环境存在捕捞压力，但该物种具有圈养养殖的潜力。关于该物种生长和性发育的信息稀缺，首次成熟的年龄和大小尚未确定。因此，共饲养了400尾鱼苗，从孵化到孵化后968天（DAH）。在整个饲养期间对鱼的性腺进行组织学分析，并比较雌雄鱼之间的生长、肝体指数和性腺指数。在845和968 DAH时对雌二醇、睾酮和17α-羟基孕酮浓度进行定量，以比较性成熟的雌雄鱼。雌雄鱼的体重和体长没有差异（P>0.05）。雄鱼在593 DAH时性成熟，体长为29.88±1.76厘米，体重为444.1±77.03克，而雌鱼在845 DAH时性成熟，体长为36.51±1.06厘米，体重为783.05±48.57克。这些结果提供了关于亚历山大低冠鲶最小捕捞尺寸的重要信息，以确定该物种开始生殖管理的合适时期。
