Composition and trophic structure of fish communities in the Ribeirão Bananal sub-basin, Parque Nacional de Brasília, biome Cerrado, DF / Composição e estrutura trófica da comunidade de peixes de riachos da sub-bacia do Ribeirão Bananal, Parque Nacional de Brasília, bioma Cerrado, DF

AUTOR(ES)
DATA DE PUBLICAÇÃO

2008

RESUMO

The purpose of this study was determined the composition and the trophic structure of fish communities in the Ribeirão Bananal sub-basin, which belongs to a well preserved Cerrado area in the National Park of Brasília, Brazil. Furthermore, due to a marked sazonality in this biome, it was examined the influence of environmental variations on the fish species diets in the study area. Therefore, in a stretch of 30 m long, four samples two in the dry season and two in the raining period were taken. A total of 3597 individuals, belonging to 20 species, were collected. Nine of them were new species for the area. The study analyzed 1050 stomachs of the 13 more abundant species. The analysis showed that a total of 36 feeding items were consumed, 24 autochthonous, 8 alochthonous and four of indetermined origin. The non-metric multidimensional scaling (NMDS) analysis, together with the results of frequency occurrence and abundance graphics, permitted to group the species in four feeding guilds: detritivores, onivores (with tendency to herbivory and invertivory), invertivores and piscivores. Only a few pairs of species showed feeding overlap and when it occurred, it was mostly among species of the same trophic guild. Around 69% of resources consumed were from alochthonous origin, which proves the importance of the resources provided by riparian vegetation. The contribution of autochthonous and alochthonous items in the diet differed according to the season for Aspidoras fuscoguttatus, Astyanax sp., Characidium sp., Hyphessobrycon balbus, Kolpotocheirodon theloura, Moenkhausia sp., Phalloceros caudimaculatus e Rivulus pictus. Despite the Cerrados climatic characteristics, there was no significant influence of seasonal variation on the diet. The absence of seasonal variation and the prevail of alochthonous items in the diet probably are associate with the presence of riparian vegetation that act as a transition area and provide resources do the aquatic fauna. This work demonstrates the importance of studies in non-disturbed areas to provide information concerning the species biology and direct the public actions to the aquatic resources management, recuperation of damaged areas and determination of priority areas to conservation.

ASSUNTO(S)

feeding guilds cerrado trophic ecology variação sazonal ecologia trófica cerrado peixes de riacho guildas alimentares seasonal variation ecologia stream fishes

ACESSO AO ARTIGO

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