Trophic ecology of the Neotropical tolerant fish Corydoras paleatus under the influence of contrasting environmental conditions in a prairie stream

BERTORA, ANDREA; FONTANARROSA, MARÍA SOLEDAD; GROSMAN, FABIÁN; SANZANO, PABLO; ROSSO, JUAN JOSE

ANAIS DA ACADEMIA BRASILEIRA DE CIENCIAS.

ACAD BRASILEIRA DE CIENCIAS

Lugar: Rio de Janeiro; Año: 2021

0001-3765

Worldwide, land use changes and urbanization affect habitat and biota instreams, drastically disrupting environmental conditions and biotic interactions. Weevaluated the trophic ecology of the tolerant fish Corydoras paleatus in a prairie streamwith contrasting environmental conditions intimately aligned with different nearby landuses. Gut analyses was conducted at three stream reaches with contrasting ecologicalattributes regarding water quality, habitat structure and riparian condition. A total of231 guts were analyzed and 15 prey items identified. A significant variation incomposition and structure of the dietary assemblage, niche breadth and feeding patternsof C. paleatus under different environmental conditions was observed. Psychodidaeprevailed in most deteriorated environmental conditions and Chironomidae, followed bynematodes, in stream reaches where environmental conditions improved. Maximumniche breadth and a larger proportion of generalist individuals were found at the mostdeteriorated site. Conversely, the proportions of specialized individuals were slightlyhigher at sites with better ecological conditions. Psychodidae and mineral fragmentswere positively correlated with the most detrimental conditions, while filamentous algaeprevailed where these conditions improved. Overall, good evidence suggesting thattrophic ecology of a tolerant species is affected by local environmental conditions inwater quality, habitat structure and riparian corridor was observed.