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Ramos J.A.A.,Instituto Federal Of Educacao | Ramos J.A.A.,Federal University of Pernambuco | Ramos J.A.A.,Institute Ecologia E Gerenciamento Of Ecossistemas Costeiros E Estuarinos Iegea | Barletta M.,Federal University of Pernambuco | And 7 more authors.
Journal of Fish Biology | Year: 2014

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. © 2014 The Fisheries Society of the British Isles. Source


Ramos J.A.A.,Instituto Federal Of Educacao | Ramos J.A.A.,Federal University of Pernambuco | Ramos J.A.A.,Institute Ecologia E Gerenciamento Of Ecossistemas Costeiros E Estuarinos Iegea | Barletta M.,Federal University of Pernambuco | And 3 more authors.
Aquatic Biology | Year: 2012

The ingestion of plastic fragments by 3 species of Gerreidae (Eugerres brasilianus, Eucinostomus melanopterus and Diapterus rhombeus) in a tropical estuary in Northeast Brazil was assessed for 3 different size classes corresponding to juveniles, sub-adults and adults. In all, 425 individuals were analysed. The gut contents of 13.4% of these individuals contained plastic debris. The only type of debris found was blue nylon fragments originating from ropes used in fishing. Artisanal fishing is the main local activity and was considered to represent the principal source of this marine debris. Significant differences in the number and weight of nylon fragments ingested were found between species and size classes. Moreover, a decrease in the weight of the gut contents was observed in the individuals that had ingested nylon fragments. In addition to the hypothesis that Gerreidae mistakenly identify nylon fragments as prey items, we propose 3 further possible pathways: (1) from fragments that the fishes' prey have already ingested; (2) through ingestion of fragments along with sediment that is sucked in during feeding; and (3) through ingestion of organisms that have aggregated on fragments. © Inter-Research 2012. Source

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