Records of cleaning symbiosis between freshwater fish are scarce. Here we report on juvenile catfish, Platydoras costatus, cleaning the piscivorous characin Hoplias cf. malabaricus in a stream of the rio Araguaia drainage in the Brazilian Amazon. The scarcity of records on cleaning behavior in freshwater systems seems to be in part a consequence of the few observational studies under natural conditions in the Neotropics. Otherwise, the rareness of this behavior in freshwaters is possibly related to the short evolutionary time available to the fish fauna to develop these complex interactions, when compared to the ocean environment.
Erythrinidae; Hoplias cf. malabaricus; piscivorous client; juvenile cleaner; rio Araguaia