Feeding habits of fish from a stream in the savanna of Central Brazil, Araguaia Basin

Abstract

The objective of the present study was to determine the composition of the diet of fish and its relation to the condition of canopy along a stream in the savanna of Central Brazil. Fish were collected monthly from April 1994 to March 1995. A total of 3872 individuals belonging to 82 species were captured and 1606 of them had their stomach content analysed. Allochthonous resources were widely used by fish. Although some fish groups do present generalist habits, most of the species can be included in well-defined trophic groups. Piscivores were abundant only during the flooding season when they occupied the stream looking for food and reproduction sites. Deforestation of the riparian forest has negative effects on the fish populations that depend on allochthonous resources. Lack of vegetation near the mouth of the river allows sand accumulation on the bottom of the stream and destruction of important microhabitats used as feeding and shelter, a fact that excluded some species from this site.Este trabalho teve como objetivo determinar a composição da dieta dos peixes e sua relação com a vegetação marginal em um córrego de cerrado no Brasil Central. Os peixes foram coletados mensalmente de abril de 1994 a março de 1995. No total, foram capturados 3872 indivíduos, distribuídos em 82 espécies, destes, 1606 foram submetidos à análise de conteúdo estomacal. Recursos alóctones foram amplamente utilizados pelos peixes. Embora existam grupos com hábitos alimentares generalistas, a maioria das espécies pôde ser incluída em grupos tróficos bem definidos. Piscívoros foram abundantes apenas no período de cheia, quando entram no córrego à procura de alimento e locais de reprodução. O desmatamento da vegetação marginal apresentou efeito negativo sobre a população de peixes que depende de recursos alóctones. A falta de vegetação, próximo à foz do córrego, facilitou assoreamento e destruição de importantes microhabitats usados para alimentação e esconderijo, fato que impediu a permanência de algumas espécies no local.

The role of riverine forests for food supply for the omnivorous fish Brycon opalinus Cuvier, 1819 (Characidae) in the Serra do Mar, Southeast Brazil

“…Other Brycon, such as Brycon melanopterus (Reimer, 1982), Brycon cephalus (Pizango-Paima et al, 2001;Figueiredo-Garutti et al, 2002), Brycon vermelha Lima and Castro, 2000and Brycon ferox Steindachner, 1877(Lima and Castro, 2000, Brycon orbignyanus (García-Carreño et al, 2002;Sá and Fracalossi, 2002), Brycon microlepis Perugia, 1897 (Sabino and Sazima, 1999), Brycon falcatus Müller and Troschel, 1844 (Melo et al, 2004), Brycon lundii (Alvim and Peret, 2004) and Brycon sp. (Jatuarana) (Goulding, 1980), have been characterized as feeding on an omnivorous diet in the most diverse environments.…”

“…These sites shelter a wide diversity and density of invertebrates when compared to the adjacent forests and comprise some of the earth's most productive ecosystems. In oligotrophic streams, the terrestrial matter carried into the water supplies an important food resource for fishes; hence, the riparian integrity is extremely important for the survival of these species (Pusey and Arthington, 2003;Melo et al, 2004). In addition to being highly sensitive to environmental changes, the riparian zone is a key factor in the maintenance of the basin's resilience (Lima, 2003).…”

Use of Food Resources by Detritivorous Fish in Flood-Plains: A Synthesis

“…Other researches, have also pointed out that the allochthonous organic matter especially from the soil taken to the water, is an important food resource for fish (Pusey and Artington 2003;Melo et al, 2004;Weidel et al, 2008;Solomon et al, 2011). This occurs especially, in lotic ecosystems, and has been an important research issue for aquatic ecologists since the beginning of the last century.…”

Variation in the diet of a small characin according to the riparian zone coverage in an Atlantic Forest stream, northeastern Brazil

“…When the riparian vegetation or the morphology of the river channel is modified, the aquatic biota become affected by high sediment transport, rise in temperature and disruption of the food chain (Dufech et al, 2003), causing the disappearance of some species from certain sites (Melo et al, 2004).…”