title: Trophic niche and habitat shifts of sympatric Gerreidae.
abstract: The diet and mouth growth rates of three Gerreidae species (Eugerres brasilianus, Eucinostomus melanopterus and Diapterus rhombeus) were assessed at different ontogenetic phases (juveniles, sub-adults and adults) in order to detect allometric growth, and whether they are related to habitat and seasonal changes in the Goiana Estuary, north-east Brazil. The importance of each prey for each ontogenetic phase was described using the index of relative importance. The three species showed seasonal ontogenetic shifts in diet and allometric growth of mouth morphology. They also had an exclusively zoobenthic diet, comprising mainly Polychaeta, Copepoda, Ostracoda, Gastropoda and Bivalvia. Mouth development showed a possible influence on diet changes for E. melanopterus. Significant interactions (P < 0·01) were detected among seasons, areas and ontogenetic phases for the most important prey for E. brasilianus and E. melanopterus. Diet overlaps are evidence of intra and interspecific competition among gerreids for specific prey. A conceptual model of the competition and seasonal diet shifts among ontogenetic phases of gerreids is given. The sediment ingested due to the feeding mechanisms of Gerreidae species could also partially explain the ingestion of synthetic items observed for all ontogenetic phases, which indicates one of a myriad effects of human activities (e.g. artisanal fishery) in this estuary.
authors.affiliation: Instituto Federal de Educação, Ciência e Tecnologia da Paraíba (IFPB)-Campus Cabedelo, Rua Santa Rita de Cássia, s/n, Jardim Jericó, Cabedelo, Paraíba, CEP 58310-000, Brazil; Laboratório de Ecologia e Gerenciamento de Ecossistemas Costeiros e Estuarinos, Departamento de Oceanografia, Universidade Federal de Pernambuco, Cidade Universitária, Recife, Pernambuco, CEP 50740-550, Brazil; Instituto de Ecologia e Gerenciamento de Ecossistemas Costeiros e Estuarinos (IEGEA), P. O. Box 8132, Recife, Pernambuco, CEP 51020-970, Brazil.
authors.forename: J A A
authors.initials: JA
authors.lastname: Ramos
authors.forename: M
authors.initials: M
authors.lastname: Barletta
authors.forename: D V
authors.initials: DV
authors.lastname: Dantas
authors.forename: A R A
authors.initials: AR
authors.lastname: Lima
authors.forename: M F
authors.initials: MF
authors.lastname: Costa
mesh_terms: D000818:Animals; D001938:Brazil; D004032:Diet; D017753:Ecosystem; D063366:Estuaries; D005399:Fishes / Q000033:anatomy & histology / Q000254:growth & development*; D005766:Gastrointestinal Contents; D009055:Mouth / Q000033:anatomy & histology; D012621:Seasons; D061350:Sympatry
keywords: Brazil; Goiana Estuary; South America; allometric growth; conceptual model of feeding; diet shift