The 40-foot male traveled from the North Pacific to Namibia, the first sighting of the species in the Southern Hemisphere.

A gray whale has swum the longest distance ever recorded in a marine vertebrate—more than 16,700 miles—over halfway around the world.

The male cetacean, spotted off Namibia in 2013, is the first gray whale ever recorded in the Southern Hemisphere.

But it took several years of genetic research to confirm the whale originated in the North Pacific, according to a study published today in the journal Biology Letters.

There are two known populations of gray whales: eastern gray whales, whose numbers are stable, with around 20,500 individuals, and western gray whales, which are endangered, with an estimated 200 individuals left in the wild, mostly due to decades of commercial whaling. Eastern grays migrate from the seas around Alaska and Russia to breeding grounds in Baja California. Much less is known about western gray whale breeding grounds, but they’ve been recorded as feeding around eastern Russia.

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