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| Barreto,Silvia B.; Silva,André T.; Souza,Fabiane B.; Jucá-Chagas,Ricardo. |
| ABSTRACT Studies on the composition of fish diet and on how species exploit food resources are especially relevant in tropical freshwater systems, where dietary plasticity is a commonly used strategy. In this study, we analysed the food spectrum and the environmental, seasonal and ontogenetic variations in the diet of a characid species [Hemigrammus marginatus Ellis, 1911 (Characidae)] in the region of the Upper Contas River, in the Diamantina Plateau, Brazil. We verified an omnivorous/invertivorous and opportunistic food habit, with predominance of insects and microcrustaceans, followed by filamentous algae. Seasonality did not alter the food resources used by the species. However, differences were detected in the dominant categories when comparing the... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: Feeding; Coastal drainage; Trophic ecology; Freshwater fishes. |
| Ano: 2018 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0073-47212018000100236 |
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| Barreto,Silvia B.; Cioffi,Marcelo B.; Medrado,Aline S.; Silva,André T.; Affonso,Paulo R. A. M.; Diniz,Débora. |
| ABSTRACT Characiformes is the most cytogenetically studied group of freshwater Actinopterygii, but karyotypical data of several taxa remain unknown. This is the case of Nematocharax , regarded as a monotypic genus and characterized by marked sexual dimorphism. Therefore, we provide the first cytogenetic report of allopatric populations of Nematocharax venustus based on distinct methods of chromosomal banding and fluorescence in situ hybridization (FISH) with repetitive DNA probes (18S and 5S rDNA). The karyotype macrostructure was conserved in all specimens and populations, independently on sex, since they shared a diploid number (2n) of 50 chromosomes divided into 8m+26sm+14st+2a. The heterochromatin was mainly distributed at pericentromeric regions and... |
| Tipo: Info:eu-repo/semantics/article |
Palavras-chave: 18S rDNA; 5S rDNA; Coastal drainages; FISH; Population cytogenetics. |
| Ano: 2016 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1679-62252016000200205 |
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