[No Title Available]

Abstract

Information related to the diet of one species always contributes to the knowledge of its bionomy and the functioning of the ecosystem in which the species lives. Therefore, understanding the feeding ecology of one fish population and its ontogenetic, spatial and temporal aspects help to understand the structure of fish assemblages and river communities. Knowledge of this structure is essential for habitat management and biodiversity conservation. The feeding ecology of Deuterodon langei Travassos, 1957 was studied through analyses of diet composition, sharing of resources, feeding strategy and contribution of food items to the width of its niche. The analysis included an assessment of ontogenetic, spatial and seasonal variations. The species was considered omnivorous with great plasticity caused by seasonal variation in food availability throughout the river basin, but mainly through ontogeny. The diet of smaller individuals revealed a predominance of insects and other arthropods, while the diet of larger specimens showed allochthonous plant items as the main components. The low intestinal quotient (IQ) values for the smaller individuals were accounted for their mainly insectivorous diet. The greater relative length of the intestine can account for the greater plasticity of the adult diet, enabling them to use diet items of larger size and more difficult digestion, such as plant items. Therefore, shifts in feeding ecology during growth are confirmed in this omnivorous tropical river fish, strengthening the concept that, when comparing food habits among species, fish size must be taken into account. This study also provides needed information regarding the feeding ecology of fishes intrinsically associated with the Atlantic rainforest, one of the most threatened and biodiverse ecosystems of the planet.Informações relacionadas à alimentação de uma espécie contribuem para o conhecimento de sua bionomia e funcionamento do ecossistema no qual ela vive. Desta forma, entender a ecologia alimentar de uma população de peixes e seus aspectos ontogenéticos, temporais e espaciais auxiliam na compreensão da assembléia de peixes e de toda a comunidade de um rio. Reconhecer tal estrutura é fundamental para o manejo e conservação da biodiversidade do habitat. A ecologia alimentar de Deuterodon langei Travassos, 1957 foi analisada por meio da composição da dieta, partilha de recursos, estratégia alimentar e contribuição dos itens alimentares para o nicho alimentar. As análises incluem uma abordagem das variações ontogenéticas, espaciais e temporais. A espécie foi considerada onívora com uma grande plasticidade alimentar causada pela variabilidade sazonal na disponibilidade de recursos e ao longo da bacia hidrográfica, mas principalmente ao longo de sua ontogenia. A dieta dos indivíduos menores revelou uma predominância de insetos e outros artrópodes, enquanto nos indivíduos maiores ocorreu um predomínio de vegetais alóctones. Os baixos valores de Quociente Intestinal (IQ) para os indivíduos menores foram associados a uma dieta ...

Flood pulse are the main determinant of feeding dynamics and composition of Odontostilbe pequira (Characiformes: Characidae) in southern Pantanal, Brazil

“…This idea corroborates the Gerking (1994) conclusions, who described the ability of fish to alter their diet in response to seasonality and food resource availability, which complicates the characterization of the trophic groups. The low frequency of empty stomachs also can be viewed as an evidence of intense feeding activity of O. pequira, as observed by Vitule et al (2008) for Deuterodon langei in streams of Atlantic rainforest in southern Brazil. The highest stomach weights were observed in the high-water period.…”

Importance of allochthonous resources in the diet ofAstyanax aff. fasciatus (Osteichthyes: Characidae) in streams: a longitudinal approach

“…Subsidies as invertebrates can represent up to half of the energy in the diet of stream fish (Masson & Macdonald 1982), indicating that in these environments the availability of prey induce higher consumption (Rezende & Mazzoni, 2006), or the fishes have a preference for these organisms (Main & Lyon 1988, Garman 1991. The importance of subsidies in the diet of stream fish has been frequently reported in tropical regions (Henry et al 1994, Vitule et al 2008, Wolff et al 2009, Tó foli et al 2010, Manna et al 2012, Small et al 2013.…”

Trophic structure of fish fauna along the longitudinal gradient of a first-order rural stream

“…especially between herbivorous and omnivorous) along the stream. Among freshwater teleosts, this group shows a remarkable food plasticity (Abelha et al, 2001;Andrian et al, 2006;Silva et al, 2014), which makes difficult a generalization into guilds (Wolff et al, 2009), since these organisms respond immediately to changes in the resource supply (Vitule et al, 2008;Wolff et al, 2009;Mazzoni et al, 2010). However, in addition to longitudinal effects, our results may have been influenced by the surrounding physiography, since it is a rural stream where the stretches of headwater and middle exhibited less altered riparian vegetation.…”