title: Eco-morphological attributes and feeding habits in coexisting characins.
abstract: The head morphology and feeding habits of pairs of characin species (family Characidae) that coexist in four different coastal rainforest streams were analysed. Coexisting species differed in size, but were very similar in eco-morphological attributes. Gut analyses revealed differences in feeding preferences for each coexisting species, indicating resource partitioning. A pattern of organization in species pairs that was repeated in the four studied streams was noticed. The pattern consisted of one slightly larger species with a feeding preference for items of allochthonous origin and another smaller species with a preference for autochthonous items. The hypothesis that small morphological differences enable the current coexistence of those species pairs was proposed. Furthermore, the results show ecological equivalence among different species in the studied streams.
authors.affiliation: Departamento de Ecologia, Instituto de Biologia Roberto Alcantara Gomes, Universidade do Estado do Rio de Janeiro-UERJ, Rua São Francisco Xavier, 524, Maracanã, CEP 20550-13, Rio de Janeiro, RJ, Brazil.
authors.forename: T
authors.initials: T
authors.lastname: Portella
authors.affiliation: Museo Nacional de Ciencias Naturales (CSIC), C/2, José Gutierrez Abascal, Madrid, 28006, Spain.
authors.forename: J
authors.initials: J
authors.lastname: Lobón-Cerviá
authors.affiliation: Departamento de Ecologia, Instituto de Biologia Roberto Alcantara Gomes, Universidade do Estado do Rio de Janeiro-UERJ, Rua São Francisco Xavier, 524, Maracanã, CEP 20550-13, Rio de Janeiro, RJ, Brazil.
authors.forename: L R
authors.initials: LR
authors.lastname: Manna
authors.affiliation: Departamento de Ecologia, Instituto de Biologia Roberto Alcantara Gomes, Universidade do Estado do Rio de Janeiro-UERJ, Rua São Francisco Xavier, 524, Maracanã, CEP 20550-13, Rio de Janeiro, RJ, Brazil.
authors.forename: H G
authors.initials: HG
authors.lastname: Bergallo
authors.affiliation: Departamento de Ecologia, Instituto de Biologia Roberto Alcantara Gomes, Universidade do Estado do Rio de Janeiro-UERJ, Rua São Francisco Xavier, 524, Maracanã, CEP 20550-13, Rio de Janeiro, RJ, Brazil.
authors.forename: R
authors.initials: R
authors.lastname: Mazzoni
mesh_terms: D000818:Animals; D049628:Body Size; D060126:Characidae / Q000033:anatomy & histology* / Q000502:physiology*; D017753:Ecosystem; D005247:Feeding Behavior / Q000502:physiology*; D005518:Food Preferences; D045483:Rivers
keywords: characid species; freshwater fishes; morphology; niche overlap; resource partitioning; streams