Feeding ecology of Hypostomus punctatus Valenciennes, 1840 (Osteichthyes, Loricariidae) in a costal stream from Southeast Brazil

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 (IA i ). 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 (IA irainny = 90.34 and IA idry = 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 ResumoNo presente estudo, tivemos como objetivo comparar a ecologia trófica de Hypostomus punctatus de um riacho costeiro do sudeste do Brasil com dados previamente publicados para a mesma localidade deste estudo, antes que tenha sofrido alterações ambientais. As preferências alimentares foram analisadas através da análise de 138 exemplares (67 da estação seca e 71 da estação chuvosa), utilizando-se o Índice de Importância Alimentar (IA i ). Registramos cinco diferentes itens alimentares (detrito, fragmentos vegetais, Diatomáceas, Clorofíceas e Cianobactérias), compondo a dieta da espécie. Detrito foi o item mais abundante, tanto durante a estação chuvosa como durante a seca (IA ichuva = 90,34 e IA iseca = 96,30). Não foram registradas diferenças significativas entre o volume consumido de cada um dos itens na estação seca e chuvosa. A análise da frequência de ocorrência mostrou que quatro (detrito, fragmento vegetal, Diatomáceas e Clorofíceas) entre os cinco itens consumidos foram sempre frequentes. Comparando nossos resultados com aqueles previamente publicados, sugerimos que o hábito alimentar de H. punctatus mudou de acordo com as alterações ambientais e que sua dieta é fortemente dependente das condições ambientais.Palavras-chave: peixe de riacho, detritivoria, hábito bentônico.

Food-resource partitioning among fish species from a first-order stream in northwestern Paraná, Brazil

“…High overlap values were recorded only between congeneric species of Characidae and Loricariidae, which because of their kinship, similar morphology and cooccurrence, used the same food sources (Casatti, 2002;Mazzoni et al, 2010c;Alves et al, 2011;Dias & Fialho, 2011). However, this high overlap was probably associated with the high abundance of these resources Dias & Fialho, 2009;Uieda & Pinto, 2011).…”

Plasticity in the diet of Astyanax taeniatus in a coastal stream from south-east Brazil

“…Aquatic larvae of the Curculionidae family (Coleoptera) are herbivorous, and inhabit emerging aquatic plants and have an intimate relationship with the aquatic and semi-aquatic flora (Triplehorn and Johnson, 2005). At this site of the Mato Grosso stream, there is marginal vegetation (Costa, 1987;Miranda, 2009;Mazzoni et al, 2010b) and as a consequence, a high availability of these invertebrates, contributing to their presence as a diet item.…”

Phosphorus body content in an herbivorous fish in environments with different trophic state

“…The habitat characteristics in this site (e.g. presence of shelter, mesohabitat heterogeneity and substrates) could be allowing fish to have better body conditions, since these characteristics directly influence the availability of food and reproduction success (Duarte et al, 2011;Mazzoni et al, 2010). Catfishes are very often associated with rocky substrates, both favouring feeding and reproduction (Casatti et al, 2005;Duarte et al, 2011).…”