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Species‐specific ontogenetic diet shifts among Neotropical Crenicichla : using stable isotopes and tissue stoichiometry
Author(s) -
Burress E. D.,
Duarte A.,
Serra W. S.,
Gangloff M. M.,
Siefferman L.
Publication year - 2013
Publication title -
journal of fish biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.672
H-Index - 115
eISSN - 1095-8649
pISSN - 0022-1112
DOI - 10.1111/jfb.12117
Subject(s) - biology , sympatric speciation , pike , ontogeny , predation , stable isotope ratio , functional response , abundance (ecology) , δ15n , isotope , ecology , ecological stoichiometry , zoology , δ13c , predator , ecosystem , fishery , fish <actinopterygii> , genetics , physics , quantum mechanics
Ontogenetic 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.