Scientists have spotted what they believe to be the first ever hybrid between a melon-headed whale and a rough-toothed dolphin near Hawaii.
The male "wholphin", which is believed to be close to adult age, was spotted swimming with dolphins near the island of Kauai last year, according to Dr Robin Baird, the marine biologist who headed the expedition.
Researchers from the Cascadia Research Collective said they were immediately attracted to the creature because of its unusual appearance.
Melon-headed whales are technically dolphins and belong to the family Delphinidae.
Hybrids within the Delphinidae are extremely rare, with only three having been confirmed.
This is believed to be the first hybrid between these two species.
Although a number of wholphins have been born in captivity, few have gone on to thrive and reproduce themselves.
Scientists are reluctant to use the term, however, and Dr Baird said the animals cannot be considered their own species without more widespread hybridisation.
He said: "Calling it something like a wholphin doesn't make any sense.
"I think calling it a wholphin just confuses the situation more than it already is."
The term was first used in 1985 at Hawaii's Sea Life Park for a hybrid between a false killer whale and an Atlantic bottle-nose dolphin.
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That hybrid, named Kekaimalu, still lives at the marine mammal park, where she helps teach children about genetics.
Hybrids generally occur when there is a decline in the population in one of the parental species.