Edward D. BurressAna Maria Ribeiro de Castro DuarteWilson S. SerraMichael M. GangloffLynn Siefferman2026-03-222026-03-22201310.1111/jfb.12117https://doi.org/10.1111/jfb.12117https://andeanlibrary.org/handle/123456789/47200Citaciones: 26Ontogenetic diet shifts were compared among five sympatric pike cichlids Crenicichla in a subtropical South American stream using stable C and N isotopes and tissue stoichiometry (C:N). Within species, stable N isotopes were positively related to body size while C:N showed negative relationships. Stable C isotopes, however, were not related to body size in any species. By modelling the switch to piscivory using gut content-isotope-body size relationships, diet shifts were shown to be species-specific with regard to both rate and degree of piscivory. Compared to other piscivorous lineages, Crenicichla appear to be unusually small-bodied (based on maximum body size). Because of their diversity, abundance and dynamic size-structured functional roles, Crenicichla may exert broad and complex predation pressures on the aquatic community.enBiologySympatric speciationPikeOntogenyPredationStable isotope ratioFunctional responseAbundance (ecology)δ15NIsotopearticle