Publication Date: 2015.
The taxonomy of common dolphins (Delphinus sp.) has always been controversial, with over twenty described species since the original description of the type species of the genus (Delphinus delphis Linnaeus, 1758). Two species and four subspecies are currently accepted, but recent molecular data have challenged this view. In this study we investigated the molecular taxonomy of common dolphins through analyses of cytochrome b sequences of 297 individuals from most of their distribution. We included 37 novel sequences from the Southwestern Atlantic Ocean, a region where the short- and long-beaked morphotypesoccur in sympatry, but which had not been well sampled before. Skulls of individuals from the Southwestern Atlantic were measured to test the validity of the rostral index as a diagnostic character and confirmed the presence of the two morphotypes in our genetic sample. Our genetic results show that all common dolphins in the Atlantic Ocean belong to a single species, Delphinus delphis. According to genetic data, the species Delphinus capensis is invalid. Long-beaked common dolphins from the Northeastern Pacific Ocean may constitutea different species. Our conclusions prompt the need for revision of currently accepted common dolphin species and subspecies and of Delphinus delphis distribution.
Author affiliation: Cunha, Haydeé A.. Universidade Do Estado de Rio Do Janeiro; Brasil
Author affiliation: Loizaga de Castro, Rocio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentina
Author affiliation: Secchi, Eduardo Resende. Universidade Federal do Rio Grande do Sul; Brasil
Author affiliation: Crespo, Enrique Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentina
Author affiliation: Lailson Brito, José. Universidade Do Estado Do Rio de Janeiro; Brasil
Author affiliation: Azevedo, Alexandre F.. Universidade Do Estado de Rio Do Janeiro; Brasil
Author affiliation: Lazoski, Cristiano. Universidade Federal do Rio de Janeiro; Brasil
Author affiliation: Solé Cava, Antonio M.. Universidade Federal do Rio de Janeiro; Brasil
Repository: CONICET Digital (CONICET). Consejo Nacional de Investigaciones Científicas y Técnicas