Population structure and the conservation status of the rough-toothed dolphins based on the analysis of the mitochondrial control region

Abstract The rough-toothed dolphin (Steno bredanensis) is found in deep waters in tropical, subtropical and warm temperate regions of the Atlantic, Pacific and Indian Oceans. In Brazil, however, they can be observed in coastal waters from north to south Brazil, a habit that makes them susceptible to several anthropogenic impacts. This species is one of the small cetaceans with the most recorded cases of accidental catches in fishing nets (bycatch). Although Steno bredanensis is classified as ‘least concern' by the IUCN RedList, little is known about its population size and population structure. The present study evaluates the genetic structure of rough-toothed dolphins based on 15 stranded individuals from Rio de Janeiro, Brazil, using the mitochondrial D-Loop region. We were not able to obtain new data on the population structure of the species in southeastern Brazil. Therefore, the structure detected by Silva et al, 2015 should continue to be accepted.