Molecular identification of cetaceans from the West Atlantic using the E3-I5 region of COI

Molecular identification is very useful in cases where morphology-based species identification is not possible. Examples for its application in cetaceans include the identification of carcasses of stranded animals in advanced state of decomposition and body parts that are illegally traded. One DNA region that is often used for molecular identification is the Folmer region of the mitochondrial gene cytochrome c oxidase subunit I (COI) (locus 48 to 705 bp). This locus has been used for the identification of several animal species, including whales and dolphins. The goal of the present study was to evaluate the usefulness of another region of COI, the E3-I5 (locus 685 to locus 1179; 495 bp) as a marker for identification of cetaceans from northeastern Canada and northeastern Brazil. The identification markers were successfully obtained for seven cetacean species after performing percent identity and Basic Local Alignment Search Tool analyses. The obtained markers are now publicly available and are useful for the identification of the endangered blue whale (Balaenoptera musculus), common minke whale (B. acutorostrata), vulnerable sperm whale (Physeter macrocephalus), harbor porpoise (Phocoena phocoena), common bottlenose dolphin (Tursiops truncatus), Guiana dolphin (Sotalia guianensis), and melon-headed whale (Peponocephala electra).