Data/hora: 09/06/2024 16:00:01

Provedor de dados: 	103	
País: 	Brazil	
Título: 	Gonadal development and reproductive period of the characin Astyanax aff. bimaculatus (Characiformes: Characidae) in a tropical reservoir in southeastern Brazil	
Autores: 	Araújo,Francisco G.; Nascimento,Aparecida A.; Gomes,Iracema D.; Sales,Armando; Oliveira,Beatriz A. Chagas de.	
Data: 	2019-01-01	
Ano: 	2019	
Palavras-chave: 	Freshwater fish; Histology; Oocyte; Spawning type; Spermatocyte.	
Resumo: 	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.	
Tipo: 	Info:eu-repo/semantics/article	
Idioma: 	Inglês	
Identificador: 	http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1984-46702019000100326	
Editor: 	Sociedade Brasileira de Zoologia	
Relação: 	10.3897/zoologia.36.e30610	
Formato: 	text/html	
Fonte: 	Zoologia (Curitiba)  v.36 2019	
Fonte: 	info:eu-repo/semantics/openAccess