Hábitos alimentares de Bryconamericus stramineus Eigenmann, 1908 (Characidae), em diferentes riachos da sub-bacia do Rio Guiraí, Mato Grosso do Sul, Brasil

Abstract

Feeding habits of Bryconamericus stramineus were described in different streams of Guiraí River Sub-basin in Mato Grosso do Sul State, Mid-West of Brazil. Fishes were sampled bi-monthly between October/06 and August/07 in seven streams and the samples were separated in two seasons: dry and wet. A total of 960 individuals were captured. B. stramineus showed an insectivore feeding habit, consuming seventeen food items. The feeding tactic of preys capture varied between the seasons and the locations. During the wet season the most important items were Hymenoptera, Diptera and Coleoptera, while Megaloptera and Diptera were the most important during dry season. In all analyzed streams, B. stramineus showed a diet basically composed by insects; the other items spent sometimes, corroborating the literature. Resumo: Os hábitos alimentares de Bryconamericus stramineus foram estudados em riachos da sub-bacia do rio Guiraí, no estado de Mato Grosso do Sul, centro-oeste do Brasil. As amostragens foram realizadas bimestralmente em sete riachos na bacia do rio Guiraí, Alto Rio Paraná, de outubro/2006 a agosto/2007. Foram capturados 960 exemplares. As amostragens foram divididas em estação chuvosa e estação seca. B. stramineus apresentou hábito alimentar insetívoro; a espécie utilizou 17 itens alimentares, sendo que a tática de consumo das presas variou entre as estações a as localidades. Durante a estação chuvosa nos estômagos prevaleceram as Ordens Hymenoptera, Diptera e Coleoptera, durante a seca predominaram as Ordens Megaloptera e Diptera. Em todos os riachos analisados, B. stramineus apresentou dieta basicamente composta por insetos, sendo os demais itens consumidos ocasionalmente, confirmando a literatura. Palavras-chave: dieta, insetivoria, caracídeo.

Feeding ecology of Dash-dot Tetra Hemigrammus belottii(Steindachner 1882) (Characiformes: Characidae) in the streams of the Urucu River basin, central Amazonia, Brazil

“…The abundance of food items may vary over time, and this variation may be reflected in the diets of fish species (Rezende & Mazzoni 2005, Barreto & Aranha 2006, Brandão-Gonçalves et al 2009, as observed in the present study, with a higher feeding intensity being recorded during the dry season. As in the present study, many species of Characidae have shown greater feeding intensity and energy storage during periods preceding the reproductive activity peaks, aiming higher reproductive success (Braga et al 1985, Hojo et al 2004, Branco et al 2005, Ballesteros et al 2009).…”

“…While a number of studies have recorded spatial and temporal variation in fish diets (Hahn et al 1992, Motta & Uieda 2004, Brandão-Gonçalves et al 2009, Lima & Behr 2010, no such pattern was recorded in H. belottii, probably related to the generalist behavior of the species, which appears to be typical of the characids (Bennemann et al 2005, Silva et al 2008, Brandão-Gonçalves et al 2009). However, the lack of variation may also be related to the abundance of resources in Amazonian streams (Knöopel 1970).…”

“…A number of studies in stream habitats have indicated that both autochthonous and allochthonous resources may be important in the diets of fishes (Sabino & Castro 1990, Barreto & Aranha 2006, Rezende & Mazzoni 2006a, Brandão-Gonçalves et al 2009, and that the consumption of items from different sources may be linked to a number of factors, such as the diversity of habitats, the degree of disturbance of the marginal vegetation, anthropogenic interference, and temporal variation (Ceneviva-Bastos & Casatti 2007, Borba et al 2008.…”

Population aspects of Bryconamericus stramineus in streams of the upper Paraná River basin, Brazil

“…Exceptions are the studies of Agostinho & Penczack (1995), Abes & Agostinho (2001), Pavanelli & Caramaschi (2003), Súarez (2008) and Súarez & Lima-Júnior (2009). The biology and ecology of stream-dwelling species remain poorly studied, possibly as a result of inadequate taxonomic knowledge, however, the high isolation level and variability in environmental conditions can lead to development of great history life strategies in stream fish, them reinforcing the need of study these fish species to define possible responses to environmental degradations.…”

“…Studies about population ecology of small fishes in the floodplain portion of the upper Paraná River are few, except for those by Benedito-Cecilio et al (1997), who analyzed the length/weight relationship for fish species from Itaipu Reservoir; Lizama & Ambrósio (1999, discussing population aspects of nine species in the floodplain area of the upper Paraná basin; Lizama & Ambrósio (2003), analyzing the mortality and recruitment pattern of Moenkhausia intermedia; Piana et al (2006), quantifying the importance of environmental factors in density variation of Serrapinnus notomelas; and Lourenço et al (2008), analyzing the length/weight relationship, recruitment and mortality of S. notomelas and B. stramineus in streams of the lower Ivinhema River basin and Benitez & Súarez (2009) analyzing population parameters for S. notomelas in middle Ivinhema River Basin. Brandão-Gonçalves et al (2009) analyzing the feeding ecology of B. stramineus in streams of the Guiraí River Basin. However, reproductive aspects are not studied by Lourenço et al (2008) and for Brandão-Gonçalves et al (2009) the only study about population ecology of small stream fishes in Ivinhema river basin.…”