Data/hora: 05/06/2024 16:59:15

Biblioteca(s): 	Embrapa Pantanal.	
Data corrente: 	10/06/1996	
Data da última atualização: 	04/04/2017	
Autoria: 	ARCIFA, M. S.; NORTHCOTE, T. G.; FROEHLICH, O.	
Título: 	Interactive ecology of two cohabiting characin fishes (Astyanax fasciatus and Astyanax bimaculatus) in an eutrophic brazilian reservoir.	
Ano de publicação: 	1991	
Fonte/Imprenta: 	Journal Tropical Ecology, v.7, p.257-268, 1991.	
Idioma: 	Inglês	
Conteúdo: 	The competitive interactions between two species of characins (Astyanax fasciatus and Astyanax bimaculatus) were investigated by studying their horizontal distribution, relative abundance and feeding habits in litoral and limnetic zones of Americana Reservoir, southern Brazil. Differences in horizontal distribution of the species maimly as adults led to their partial habitat segregation. Most adult A. bimaculatus were litoral dwellers, whereas A. fasciatus adults were distributed from inshore to offshore waters, but with most in the latter region. Both are facultative zooplanktivores in the reservoir, feeding mostly on planktonic crustaceans, insects (chiefly chironomids) some higher plant material, detritus and even fish scales (A. bimaculatus). Food overlap coefficients, considering adult and juvenile stages of both species are large in dry as well as wet seasons, although in the dry season the overlaps are significantly reduced for juveniles of both species and for juveniles of A. bimaculatus versus adults of A. fasciatus. Both species prey more on cladocerans than on cyclopoid copepods, and the adults selectively take larger forms (Daphnia gessneri and Moiuna micrura) in the reservoir (as in previously reported enclosure experiments). Juveniles prey heavily on Bosmina longirostris. These two formerly riverine species may reduce competition, in the reservoir, by partial habitat segregation in older stages, a mechanism to avoid competition, which may have existed in their previous interactive history in rivers.	
Thesagro: 	Ecologia; Peixe.	
Thesaurus Nal: 	Astyanax; Brazil; ecology; fish.	
Categoria do assunto: 	--	
Registro original: 	Embrapa Pantanal (CPAP)	
Exemplares: 	CPAP - (32469-1) - ADD - SP - PP - SP14885 -  - 14885 - DIS