Feeding habits of the franciscana dolphin (Pontoporia blainvillei) in south-eastern Brazil

This study evaluated the feeding habits of the franciscana dolphin (Pontoporia blainvillei) in south-eastern Brazil. Stomach contents were collected from a total of 145 dead specimens found incidentally caught by fishing vessels or stranded between 2005 and 2015. Fish otoliths, cephalopod beaks and...

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Detalhes bibliográficos
Autores: Campos, Laura Busin, Lopes, Xênia Moreira [UNESP], Da Silva, Ednilson, Santos, Marcos César De Oliveira
Formato: artículo
Estado:Versión publicada
Fecha de publicación:2020
País:Brasil
Recursos:Universidade Estadual Paulista (UNESP)
Repositorio:Repositório Institucional da UNESP
Idioma:inglés
OAI Identifier:oai:repositorio.unesp.br:11449/200114
Acesso em linha:http://dx.doi.org/10.1017/S0025315420000120
http://hdl.handle.net/11449/200114
Access Level:acceso abierto
Palavra-chave:Feeding habit
Pontoporia blainvillei
South-western Atlantic
Stomach content analysis
Descrição
Resumo:This study evaluated the feeding habits of the franciscana dolphin (Pontoporia blainvillei) in south-eastern Brazil. Stomach contents were collected from a total of 145 dead specimens found incidentally caught by fishing vessels or stranded between 2005 and 2015. Fish otoliths, cephalopod beaks and whole non-digested prey were used for prey species identification. A total of 9337 prey items were identified, including 26 species of teleost fishes and three species of cephalopods. The most important prey families were Sciaenidae among fish and Loliginidae among cephalopods. Franciscana dolphins tended to feed on small fish (mean = 5.25 cm) and cephalopods (mean = 8.57 cm). The index of relative importance (IRI) showed that Pellona harroweri and Doryteuthis plei were the most important prey for both males and females. The PERMANOVA test confirmed that there is no significant difference between the feeding habits of different sexes, but detected a significant difference among seasons. Overall, our results show that franciscana dolphins are predominantly ichthyophagous and non-selective in relation to the type of prey, feeding on pelagic, demersal and pelagic-demersal prey.