August 6, 2013
A recent paper, led by authors from the Southwest Fisheries Science Center, indicates that there are multiple species of killer whale. The paper "Complete mitochondrial genome phylogeographic analysis of killer whales (Orcinus orca) indicates multiple species" describes sympatric ‘ecotypes’ with discrete prey preferences, morphology and behaviors. Although these ecotypes avoid social interactions and are not known to interbreed, previous genetic studies had found extremely low levels of diversity in the mitochondrial control region, and few clear phylogeographic patterns worldwide. New high-throughput DNA sequencing methods allowed sequencing of complete mitochondrial genomes from killer whales to provide greater resolution of the evolutionary relationships among different types of killer whales. Similar methods were recently used to identify a new species of killer whale in the subantarctic regions called "type D", based on DNA extracted from the only known museum specimen of this rarely seen species.
Read more about the Marine Mammal Genetics Group's killer whale research: Taxonomic status of Antarctic killer whales.
Read more about new killer whale species at Wired.com and Science News.