CYT B L15601 and H15748 primers for genetic identification of cetacean species

Dolphins and other cetacean are protected species whose capture is illegal in many countries. Despite the high mercury content accumulated by these animals, occasional episodes of illegal fishing occur to supply certain black markets with dolphin meat. When fishing authority inspections detect meat portions presumably of cetacean origin, it is particularly necessary to identify the species before taking the case to court. The mitochondrial cytochrome b gene has been used extensively to identify species. In forensic cases, due to the degradation of the samples, short amplicons are preferable. The universal cyt b L15601 and H15748 primers, previously tested in 63 species, have been used in this work on individuals of seven species of cetaceans: Balaenoptera physalus, Delphinus delphis, Globicephala melas, Phocoena phocoena, Stenella coeruleoalba, Tursiops truncatus and Ziphius cavirostris. These universal primers, with a short amplicon of 148 bp, have the advantage of identifying postmortem samples even when showing obvious signs of degradation. Our results showed that all tested species were correctly identified, except S. coeruleoalba and S. clymene. This is because S. clymene arose by hybrid speciation between S. coeruleoalba and S. longirostris. Therefore, their identification requires the analysis of both mitochondrial DNA and nuclear DNA. In summary, the identification of illegally obtained cetacean meat can be easily performed in forensic laboratories by analyzing a short fragment of the mitochondrial cyt b in all the studied species except in S. coeruleoalba and S. clymene and even when the remains were in an advanced stage of degradation.