EVIDENCE OF A FAILED PREDATION ATTEMPT ON A GUIANA DOLPHIN, Sotalia guianensis, BY A BULL SHARK, Carcharhinus leucas, IN BRAZILIAN WATERS

Authors

  • Marcos César de Oliveira Santos Projeto Atlantis, Laboratório de Biologia da Conservação de Cetáceos, Instituto de Biociências, Universidade Estadual Paulista (UNESP), Rio Claro, SP
  • Otto Bismarck Fazzano Gadig Universidade Estadual Paulista (UNESP), Campus Experimental do Litoral Paulista, São Vicente, SP. Bolsista de Produtividade do CNPq

DOI:

https://doi.org/10.32360/acmar.v42i2.6032

Keywords:

Carcharhinus leucas, Sotalia guianensis, shark-cetacean interactions, shark-infl icted wounds

Abstract

Even though shark-cetacean interactions have been the subject of numerous studies worldwide, several ecological aspects such as competition, predation risk and co-evolution remain unclear. On February 16th, 2008, during a photo-identifi cation survey to investigate population parameters of Guiana dolphins, Sotalia guianensis, in estuarine waters of Paraná State (25o S; 48o W), Brazil, an adult dolphin was photographed without its dorsal fi n. A detailed analysis of the healed area on the injured dolphin showed that the circular, crescent-shaped outlined wound was provoked by the bite of a bull shark, Carcharhinus leucas. Wound shape, prey-predator distributional patterns (sympatry) and feeding habits of the shark species here considered were indicative of the species’ identity. The wound is likely to be the result of a failed predation attempt. Interactions between C. leucas and S. guianensis should be expected, since they are sympatric along almost all of their distribution range in the tropical and subtropical western South Atlantic. The presented observation adds S. guianensis to the list of cetacean species involved in interactions with large coastal predatory sharks.

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Published

2009-12-01

Issue

Section

Notas Científicas