Feeding ecology of Hypostomus punctatus Valenciennes, 1840 (Osteichthyes, Loricariidae) in a costal stream from Southeast Brazil
Mazzoni, R.*, Rezende, CF. and Manna, LR.
Laboratório de Ecologia de Peixes , Departamento de Ecologia, Universidade do Estado do Rio de Janeiro – IBRAG, Rua São Francisco Xavier, 524, CEP 20550-013, Rio de Janeiro, RJ, Brazil *e-mail mazzoni@uerj.br Received June 25, 2009 – Accepted September 18, 2009 – Distributed August 31, 2010 (With 3 figures)

Abstract
In the present study we aimed to compare the feeding ecology of Hypostomus punctatus from a coastal stream from Southeast Brazil with data previously published for the same study site before environmental changes. Feeding preferences were assessed through a sample of 138 specimens (67 from the dry and 71 from the rainy season) using the Index of Alimentary Importance (IAi). We registered five different food items (detritus, plant fragments, Diatoms, Chloroficeae and Cianobacteries) composing the species diet. Detritus was the most abundant one both during the rainy and dry seasons (IAirainny = 90.34 and IAidry = 96.30). No significant differences were registered for the volume of food items consumed during the rainy and dry seasons. The Frequency of Occurrence analysis showed that four (detritus, plant fragments, Diatoms and Chloroficeae) among the five all other consumed ones, were always frequent. Comparing our own results with those available for the study site, we suggest that the feeding habit of H. punctatus has changed according to environmental changes and that the species diet is strongly dependent upon environmental conditions. Keywords: stream-dwelling fish, detritivorous, benthonic behaviour.

Ecologia trófica de Hypostomus punctatus Valenciennes, 1840 (Osteichthyes, Loricariidae) de um riacho costeiro do sudeste do Brasil
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