NE Pacific Transient killer whale is seen in this undated photograph taken in Alaska. Note the typical black and white color pattern and eye-patch, similar to Antarctic Type-A killer whales, but genetically distinct. The Transients are known to feed on all types of marine mammals, including other whales, dolphins, and seals and sea lions. Killer whales, also known as orcas, include several distinct species, according to genetic evidence published on April 22, 2010. Tissue samples from 139 killer whales from around the world point to at least three distinct species, the researchers report in the journal Genome Research. REUTERS/Dave Ellifrit/NOAA Alaska Fisheries Science Center /Handout (UNITED STATES – Tags: ENVIRONMENT SCI TECH) FOR EDITORIAL USE ONLY. NOT FOR SALE FOR MARKETING OR ADVERTISING CAMPAIGNS [PNG Merlin Archive]