First record of association between Potamotrygon leopoldi Castex & Castello, 1970 and Cichla melaniae Kullander & Ferreira, 2006 in the Amazon Basin, Brazil

Abstract

Abstract Nuclear-follower foraging associations, in which one species disturbs the substrate while others opportunistically feed on displaced prey, are well documented in marine ecosystems and increasingly reported in freshwater systems. Here, we present the first record of such an association involving two endemic species from the Xingu River, Brazil: the freshwater stingray Potamotrygon leopoldi as the nuclear species and the peacock bass Cichla melaniae as the follower. The interaction was observed through scientific diving in a high-flow, rocky-bottom section of the Volta Grande do Xingu. A single P. leopoldi individual was seen disturbing the substrate and consuming gastropod mollusks (Doryssa starksi), while a C. melaniae individual closely followed, likely feeding on exposed prey remains. This observation supports previous reports of similar associations involving other Potamotrygon and Cichla species and highlights the potential trophic plasticity and opportunistic behavior of C. melaniae. Given the increasing threats to the Xingu River’s biodiversity, including hydrological alterations and habitat degradation, documenting such interactions is crucial for understanding and conserving the ecological dynamics of this unique ecosystem.