Melo Rafael Magno Costa, Arantes Fábio Pereira, Sato Yoshimi, dos Santos José Enemir, Rizzo Elizete, Bazzoli Nilo
Ichthyology Department, Graduate Program on Zoology of Vertebrates, Pontifical Catholic University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil.
J Morphol. 2011 May;272(5):525-35. doi: 10.1002/jmor.10931. Epub 2011 Jan 18.
We studied the relationship between the morphology of the reproductive system and the reproductive strategies of six neotropical catfishes using macroscopic and microscopic analyses. The reproductive system of the examined Siluriformes showed diversified characteristics, but permitted their being grouped according to three reproductive strategies: pelagic spawning, demersal spawning, and internally fertilizing. The pelagic spawners Pseudoplatystoma corruscans and Conorhynchos conirostris have testes that are characterized by filiform lobes, absence of testicular secretion, full-grown oocytes of small diameter, thin zona radiata, and cuboidal follicular cells. Pimelodus maculatus is morphologically distinct from the other two pelagic spawners catfishes due to the presence of testicular secretion. The demersal spawners Lophiosilurus alexandri and Rhinelepis aspera possess homogeneous testicular secretion, large mature oocytes, and columnar follicular cells. The most specialized reproductive system was observed in the internally fertilizing Trachelyopterus galeatus, which possesses a seminal vesicle accessory to the testes, spermatozoa with elongated nuclei that form spermatozeugmata, and a secretory ovarian lamellar epithelium that is associated with sperm storage. The reproductive system observed in Neotropical catfishes showed a relationship associated with the type of fertilization and the reproductive strategies of the six species studied.
我们通过宏观和微观分析研究了六种新热带鲶鱼的生殖系统形态与生殖策略之间的关系。所研究的鲶形目鱼类的生殖系统呈现出多样化的特征，但可根据三种生殖策略进行分类：浮游产卵、底栖产卵和体内受精。浮游产卵的科氏真巨鲶和锥吻真巨鲶的睾丸具有丝状叶、无睾丸分泌物、直径小的成熟卵母细胞、薄的放射冠和立方形滤泡细胞。黄斑油鲶在形态上与其他两种浮游产卵鲶鱼不同，因为它存在睾丸分泌物。底栖产卵的亚历山大低眼无齿鲶和糙鳞斜项鲇具有均匀的睾丸分泌物、大的成熟卵母细胞和柱状滤泡细胞。在体内受精的盖斑陶乐鲶中观察到最特殊的生殖系统，它具有与睾丸相连的精囊、具有细长细胞核并形成精子束的精子，以及与精子储存相关的分泌性卵巢板层上皮。在新热带鲶鱼中观察到的生殖系统显示出与受精类型和所研究的六个物种的生殖策略相关的关系。
