New York: An international team of scientists has identified a rare new species of beaked whale that ranges from northern Japan across the Pacific Ocean to Alaska's Aleutian Islands.
Japanese whalers call the enigmatic black whales "karasu," the Japanese word for raven. The new species is darker in colour and about two-thirds the size of the more common Baird's beaked whale, but so scarce that even whalers rarely see them.
A DNA analysis of 178 beaked whales from around the Pacific Rim found eight known examples of the new species, the scientists reported in the journal Marine Mammal Science.
The eight included specimens from the Smithsonian Institution and Los Angeles County Museum of Natural History, a skeleton on display in an Alaska high school, and another that puzzled researchers trying to identify it when it washed up on an island in the Bering Sea.
In 2014 scientists found a dead beaked whale on St. George Island, one of the Pribilof Islands in the Bering Sea. It did not match any known species,and genetic tests later showed it to be the new species.
"The challenge in documenting the species was simply locating enough specimens to provide convincing evidence," said lead author of the new study Phillip Morin, a research molecular biologist at the National Oceanic and Atmospheric Administration's Southwest Fisheries Science Center in the US.
"Clearly this species is very rare, and reminds us how much we have to learn about the ocean and even some of its largest inhabitants," Morin said.
An earlier Japanese study had suggested that the black whales, sometimes considered a dwarf form of Baird's beaked whale, might represent a new species.
That sent Morin in search of additional genetic samples to definitively answer the question and better understand the range of the elusive species.
Official recognition and naming of the species awaits a formal review of the animal's characteristics and differences from other beaked whales.