Microscopic Evidence of the Opportunistic Reproductive Strategy and Early Sexual Maturation of the Small-Sized Characin Knodus moenkhausii (Characidae, Pisces)

Autor(es)

Ceneviva-Bastos, M. ; Taboga, S. R. ; Casatti, L.

• Tipo de documento: Artigo Científico
• Fonte: ANATOMIA HISTOLOGIA EMBRYOLOGIA; v. 44, n. 1, p. 9-pg., 2015-02-01.

Resumo

We investigated the reproductive biology of Knodus moenkhausii, an abundant small-sized characin fish with broad occurrence in the Parana River basin, Brazil. Specimens were collected monthly to determine fecundity, length at first maturity, reproductive period and spawning type. Gonads were macroscopically classified according to their form, size and texture in three different stages (immature, maturing or mature). Histological procedures were conducted to confirm gonadal developmental stages, and it was possible to notice that maturing females actually presented atretic oocytes, and all males that were macroscopically classified as immature, maturing and mature actually presented abundant spermatozoa in their gonads. Because of these discrepancies, a reclassification of gonadal maturations stages was needed after histological analysis, reinforcing its importance to studies on the reproduction of small characins. Reproduction occurred throughout the year though with two peaks. The length of the smallest mature individuals was 13mm SL for males and 24mm SL for females. Despite presenting relatively small batch fecundity, some life history traits such as early reproduction, multiple spawning throughout the year, in association with known opportunistic feeding habits, explain the high abundance of this species in locations where it occurs. (AU)

• Processo FAPESP: 01/13340-7 - Avaliação da integridade biótica dos riachos da região Noroeste do estado de São Paulo, bacia do Alto Paraná, utilizando comunidades de peixes
• Beneficiário: Lilian Casatti
• Modalidade de apoio: Auxílio à Pesquisa - Programa BIOTA - Jovens Pesquisadores
• Processo FAPESP: 04/12214-6 - Biologia de Knodus moenkhausii (Teleostei, Characidae) em riachos do Alto Paraná: alimentação, ocorrência e reprodução
• Beneficiário: Mônica Ceneviva Bastos
• Modalidade de apoio: Bolsas no Brasil - Mestrado
• Processo FAPESP: 11/11641-1 - Efeitos do incremento da complexidade estrutural em riachos degradados: dinâmica de detritos, fluxos de energia e tramas alimentares
• Beneficiário: Mônica Ceneviva Bastos
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado