De Souza Thiago G, Hainfellner Patrick, Kuradomi Rafael Y, Muñoz Mario E, Honji Renato M, Moreira Renata G, Batlouni Sergio R
Centro de Aquicultura, Universidade Estadual Paulista (UNESP), Campus de Jaboticabal, Jaboticabal, São Paulo, Brazil.
Instituto de Biociências, Universidade de São Paulo (USP), Campus de São Paulo, São Paulo, SP, Brazil.
Theriogenology. 2015 Mar 15;83(5):797-807. doi: 10.1016/j.theriogenology.2014.11.018. Epub 2014 Nov 20.
The aims of this study were to evaluate the characteristics of the reproductive classes and semen quality in curimbatá (Prochilodus lineatus) breeders maintained in two different rearing systems. To achieve this goal, cages (Cs) and earthen ponds (EPs) were used as experimental systems to provide unsuitable and suitable conditions, respectively. The fish were maintained under the experimental conditions for 18 months. During this period, males were randomly sampled every 2 months for biometric analysis (n = 30 per sample) and for an evaluation of selected characteristics of the testes (n = 5 per sample). After this period, males maintained in EPs and males maintained in Cs (CMs) were evaluated in induced breeding experiments. We observed that rearing P. lineatus in a C at a high stocking density for the long 18-month period of study produced reductions in growth, testis development, gonadosomatic index values, and sperm quality in the fish. We found differences between the groups in all the reproductive classes examined, especially in the regression class, which showed a pronounced accumulation of immature germ cells in the CMs. In this group, we also noted a less intense transition from a continuous to discontinuous germinal epithelium, with an extended and abnormal but less intense spermatogenic period resulting in decreases in semen volume and sperm concentration in the breeding season. Together, such dysfunctions resulted in the production of low-quality sperm in the CMs, as demonstrated by lower-quality DNA (as evaluated by the comet assay), low fertilization success, and low hatching success. In conclusion, to ensure high-quality semen in P. lineatus, appropriate management conditions must be provided throughout the reproductive cycle, especially for the regressed class, even in winter, two seasons before the breeding season.
本研究的目的是评估在两种不同养殖系统中饲养的细纹锯脂鲤（Prochilodus lineatus）亲鱼的繁殖类别特征和精液质量。为实现这一目标，分别使用网箱（Cs）和土池（EPs）作为实验系统，以提供不适合和适合的条件。鱼在实验条件下饲养18个月。在此期间，每2个月随机抽取雄性进行生物测量分析（每个样本n = 30）和评估睾丸的选定特征（每个样本n = 5）。在此期间过后，对饲养在EPs中的雄性和饲养在Cs中的雄性（CMs）进行诱导繁殖实验评估。我们观察到，在长达18个月的研究期间，将细纹锯脂鲤高密度饲养在网箱中会导致鱼的生长、睾丸发育、性腺指数值和精子质量下降。我们发现，在所检查的所有繁殖类别中，各组之间存在差异，尤其是在退化类别中，CMs中显示出未成熟生殖细胞的明显积累。在这一组中，我们还注意到从连续生精上皮到不连续生精上皮的转变不太强烈，生精期延长且异常但不太强烈，导致繁殖季节精液体积和精子浓度下降。总之，这些功能障碍共同导致CMs产生低质量的精子，这表现为DNA质量较低（通过彗星试验评估）、受精成功率低和孵化成功率低。总之，为确保细纹锯脂鲤精液的高质量，必须在整个繁殖周期提供适当的管理条件，特别是对于退化类别，即使在繁殖季节前两个季节的冬季也是如此。
