Feeding habits and morphometry of Iheringichthys labrosus (Lütken, 1874) in the Uruguay River (Uruguay)

Abstract

Body size and diet of organisms are fundamental attributes which determine their ecology and natural history. Iheringichthys labrosus is one of the most common fish species of the Uruguay River. However, its natural history is poorly known and there is little information about its diet and interactions with other species. This paper describes the feeding habits of this species, relating feeding patterns to the size classes and morphometry of individuals and to the temporal variations. Fishes were captured in May and November of 2006 in three zones of the lower Uruguay River. A total of 101 stomach contents was analyzed (standard length: 60-224 mm). The species exhibited a broad feeding spectrum with most items belonging to the benthic community. We found significant diet differences between size classes and studied months. However, we have not found a close relationship between changes in morphometric variables and diet shifts between size classes.O tamanho do corpo e a dieta são atributos fundamentais que determinam a ecologia e a história de vida dos organismos. Iheringichthys labrosus é uma das espécies mais comuns do rio Uruguai, entretanto, sua história natural é pouco conhecida e particularmente existe pouca informação sobre sua dieta e interações com outras espécies. Este artigo descreve os hábitos alimentares de I. labrosus, associando os padrões de alimentação com as classes de tamanho, à morfometria dos indivíduos e às variações temporais. Um total de 101 estômagos foi analisado (comprimento padrão: 60-224 mm). Os peixes foram capturados durante Maio e Novembro de 2006 em três áreas da porção inferior do rio Uruguai. Iheringichthys labrosus exibiu um amplo espectro alimentar, com a maioria dos componentes da dieta pertencentes à comunidade bentônica. Foram encontradas diferenças significativas na dieta em relação às classes de tamanho dos indivíduos e aos meses de estudo. No entanto, não foram encontradas relações estreitas entre as variáveis morfométricas analisadas e variações na dieta entre as classes de tamanho.

Use of food resources by small fish species in Neotropical rivers: responses to spatial and temporal variations

“…Furthermore, the result of the null model suggests that resource partitioning is occurring between the species studied, which supports the results of several studies in Neotropical environments (MÉRONA & RANKIN-DE-MÉRONA 2004, RUSSO et al 2004, NOVAKOWSKI et al 2008, BRASIL-SOUZA et al 2009, CORRÊA et al 2009, 2011, ALVES et al 2011, SILVA et al 2012. The use of resources at different spatial and temporal scales, and different strategies to obtain food, favor resource partitioning, and therefore a lower overlap in resource utilization among different species.…”

Structure dynamics of a fish community over ten years of formation in the reservoir of the hydroelectric power plant in upper Uruguay River

“…With efficient reproductive strategies and high alimentary plasticity (Hirt et al, 2011;Vidotto-Magnoni and Carvalho, 2009;Teixeira and Bennemann, 2007;Santos et al, 2004;Luz-Agostinho et al, 2006;Masdeu et al, 2011) A. fasciatus, A. affinis and I. labrosus were also abundant in the Itá reservoir, demonstrating good adaptability to the new environments formed.…”

Feeding ecology of immature Lithodoras dorsalis (Valenciennes, 1840) (Siluriformes: Doradidae) in a tidal environment, estuary of the rio Amazonas

“…Therefore, during the year, species may present a specialist or generalist behaviour in obtaining food resources, depending on availability (Abelha et al, 2001;Wolff et al, 2009;Mazzoni et al, 2010;Masdeu et al, 2011;Correa & Winemiller, 2014). Considering the low taxonomic variety of items ingested, L. dorsalis exhibited a behariour tending to specialist, eating principally fruits and seeds from the riparian forest, varying the species consumed probably according to availability.…”