Dieta do cascudo Aspidoras fuscoguttatus (Ostariophysi, Callichthyidae) em riachos com diferentes características limnológicas e estruturais

Abstract

Abstract:In the present study Aspidoras fuscoguttatus Nijssen & Isbrücker, 1976 diet was investigated based on specimens from 18 streams of São Paulo State northwestern region, upper Rio Paraná system. Stomach contents of 246 specimens were analyzed, with the registration of 26 types of feeding items showing high predominance of the autochthonous ones. Of these, Chironomidae, Simuliidae, and Ceratopogonidae aquatic larvae were the most important items, but the contribution of detritus, testate amoebas, and vegetal debris changed according to streams features. Whereas in clear waters feeding items can be visually selected by fishes, in turbid waters this selection may not occur. Thus, the species' ability in taking resources in sandy streams with turbid waters and the abundance of resources (Chironomidae larvae) are factors that seem to explain its high abundance and broad occurrence in the region. Foram analisados os conteúdos gástricos de 246 indivíduos, com o registro de 26 tipos de itens alimentares e predominância de itens autóctones. Destes, larvas de Chironomidae, Simuliidae e Ceratopogonidae foram os mais importantes, mas a contribuição de detritos, tecamebas e fragmentos de vegetais variou de acordo com as características dos riachos. Enquanto em águas mais claras os itens alimentares podem ser visualmente selecionados pelos peixes, em águas mais turvas essa seleção pode ocorrer. Assim, a habilidade da espécie em obter recursos em riachos com fundos arenosos e águas turvas e a abundância de recursos (larvas de Chironomidae) são fatores que parecem explicar a elevada abundância e ampla ocorrência da espécie na região. Palavras-chave: dieta, Chironomidae, matéria orgânica, fragmentos de vegetais, tecamebas.

The influence of environmental variables on the functional structure of headwater stream fish assemblages: a study of two tropical basins in Central Brazil

“…Turbidity and conductivity may limit species occurrence in local fish assemblages. For example, the species of catfish Aspidoras fuscoguttatus Nijssen & Isbrücker, 1976 was already found in association with high levels of water turbidity (Araújo & Garutti, 2003) that may affect its diet (Casatti et al, 2009). In our sampled streams, a species of the same genus (Aspidoras sp.)…”

Isotopic variation in five species of stream fishes under the influence of different land uses

“…Despite the limitation of the results regarding the overlap of isotopic signatures, the partition of resources used by each species reinforces other studies that investigated their feeding preferences using stomach content analyses (Table II). According to Casatti et al (2009), A. fuscoguttatus, although classified as invertivorous, has the ability to consume a variety of food items, predominantly autochthonous items, with chironomid larvae and other insects being the most consumed items. The same pattern was observed in this study, with most of the carbon incorporated by A. fuscoguttatus originating from benthic macroinvertebrates in all stream categories.…”

Water beetles in mountainous regions in southeastern Brazil

“…This is due in part to the importance this group in aquatic environments, both in abundance and diversity (Gray, 1981;Ramirez and Pringle, 1998;Stenert et al, 2004;Tupinambas et al, 2007;Paula and Fonseca-Gessner, 2010), as well as in the dynamics of aquatic systems, as part of the energy flow and nutrient dynamics (Larson, 1997;Peterson et al, 1999;Casatti et al, 2009;Vinnersten et al, 2009;Cobbaert et al, 2010). In recent years, water beetles have been gaining attention in monitoring programmes and environmental assessments, due to the sensitivity of some families to environmental change (Hilsenhoff, 1977;Ribera and Foster, 1992;Ribera, 2000;Garcia-Criado and Fernandez-Aláez, 2001;Compen and Céréghino, 2003).…”