Genomic Analysis Indicates Mulitples Species of Killer Whale

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, genetic studies to date have found extremely low levels of diversity in the mitochondrial control region, and few clear phylogeographic patterns worldwide.

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Three different Antarctic killer whales: Top - Type A; Middle - Type B; Bottom - Type C (as designated by Pitman and Ensor, J. Cetacean Research and Management, 5(2):131-139). Illustration not to scale.

Illustration credit: Uko Gorter

The following killer whales are recommended for separate species status:

/uploadedImages/Divisions/PRD/Programs/Population_Identy/PackIce_Antarctica.jpg Type-B “pack ice killer whale” from the Antarctic. Note the large eye-patch and two-tone gray color pattern. This type specializes in hunting seals, which are often on the ice and need to be knocked off the ice by the whales before they can be caught.

Photo Credit: Bob Pitman, NOAA Southwest Fisheries Science Center

/uploadedImages/Divisions/PRD/Programs/Population_Identy/RossSea_Antarctica.jpg Type-C “Ross Sea killer whale” from the Antarctic. Note the narrow angled eye patch. These are the smallest of the 3 Antarctic types and they eat fish that are found primarily under the ice pack, so they follow leads deep into the ice as it breaks up in the summer months.

Photo Credit: Bob Pitman, NOAA Southwest Fisheries Science Center


Photo Credit: Dave Ellifrit, NOAA Alaska Fisheries Science Center

Species not known:

/uploadedImages/Divisions/PRD/Programs/Population_Identy/TypeA_Antarctica.jpgType-A killer whale from the Antarctic. Note the striking black and white color pattern. This type is found in open water areas and feeds primarily on other cetaceans (whales and dolphins).

Photo Credit: John Durban, NOAA Southwest Fisheries Science Center

Last modified: 12/24/2014