Opportunistic predation of fish by anomuran crabs (Crustacea, Anomura, Aeglidae) in rivers of southern Brazil

Abstract

The opportunistic predation on the fishes Astyanax fasciatus and Crenicichla sp. entangled in gill net by the aeglid crabs Aegla grisella and Aegla singularis was observed in rivers of southern Brazil. These events occurred in two rivers located at the National Forest of Passo Fundo, in Mato Castelhano municipality, Rio Grande do Sul State and Tangará municipality, Santa Catarina State. In both places the fish showed similar wound pattern, with eyes and fins being consumed first. However, predation of the whole body was also recorded, probably due to the high number of aeglid crabs feeding on the same individual. This record intended to contribute for understanding the natural diet of these crabs in freshwater environments.