Comparative morphology of the gonadal structure related to reproductive strategies in six species of neotropical catfishes (Teleostei: Siluriformes)

Authors

  • Rafael Magno Costa Melo,

    1. Ichthyology Department, Graduate Program on Zoology of Vertebrates, Pontifical Catholic University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
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  • Fábio Pereira Arantes,

    1. Morphology Department, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
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  • Yoshimi Sato,

    1. Reproduction Department, Hydrobiology and Fishculture Station of Três Marias, Três Marias, Minas Gerais, Brazil
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  • José Enemir dos Santos,

    1. Ichthyology Department, Graduate Program on Zoology of Vertebrates, Pontifical Catholic University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
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  • Elizete Rizzo,

    1. Morphology Department, Institute of Biological Sciences, Federal University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
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  • Nilo Bazzoli

    Corresponding author
    1. Ichthyology Department, Graduate Program on Zoology of Vertebrates, Pontifical Catholic University of Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
    • Programa de Pós-Graduação em Zoologia de Vertebrados, PUC Minas-Av. Dom José Gaspar, n 500-30535-610, Belo Horizonte-MG, Brazil
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Abstract

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. © 2011 Wiley-Liss, Inc.

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