Gonadal development and reproductive period of the characin Astyanax aff. bimaculatus (Characiformes: Characidae) in a tropical reservoir in southeastern Brazil
Zoologia (Curitiba, Impr.)
; 36: e.30610, Apr. 18, 2019. ilus, tab, graf
Article
em En
| VETINDEX
| ID: biblio-1504566
Biblioteca responsável:
BR68.1
Localização: BR68.1
ABSTRACT
The gonadal development of the characin Astyanax aff. bimaculatus from Funil Reservoir, an impoundment in the middle reaches of the Paraiba do Sul River in southeastern Brazil was analysed through histological, histochemical and histometric techniques, and the spawning season was determined. Unbalanced sex ratio was found, with females outnumbering and reaching larger sizes than males. The following stages of oogenic cell development were identified for females primary growth, pre-vitellogenic (cortical alveolar) and vitellogenic. In males, the following stages were determined spermatogonia primary and secondary, spermatocyte primary and secondary, spermatid and spermatozoa. The spawning occurs most of the year, peaking in January-February, as indicated by the gonadosomatic index. In the peak of the spawning period, the condition factor and hepatosomatic indices decreased suggesting use of stored body energy reserves during the reproduction. Spawning in batches, small-sized oocytes and a long reproductive season suggest that Astyanax aff. bimaculatus fits to an opportunist strategy. Such strategy may facilitate the use of a wide range of lentic and lotic body waters in the Neotropical region.
Palavras-chave
Texto completo:
1
Base de dados:
VETINDEX
Assunto principal:
Oócitos
/
Reprodução
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Espermatócitos
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Characidae
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Gônadas
Limite:
Animals
País/Região como assunto:
America do sul
/
Brasil
Idioma:
En
Revista:
Zoologia (Curitiba, Impr.)
Ano de publicação:
2019
Tipo de documento:
Article
/
Project document