Last year, ocean researchers with the nonprofit Cascadia Research Collective were on a trip to study marine mammals in the waters around the Hawaiian island of Kauai, when they spotted a sea creature that seemed to have a mix of features shared by two distinct species. And it got them curious...
The unknown creature's dorsal fin is steep, like that of a melon-headed whale. But scientists observed that its face was not as round as the whale species, and instead resembled that of a rough-toothed dolphin.
Another hint that the animal was a hybrid was that its underside shared the splotchy coloring of rough-toothed dolphins, while its top half matched more closely with the light gray of melon-headed whales.
A pod of rough-toothed dolphins swimming near Kauai.
Because of the animal's spotted look, the boat crew nicknamed it Oreo, according to the Garden Island, which talked to Cascadia Research's project leader Robin Baird.
A final indicator that the animal was unique was that it was swimming with just one other melon-headed whale — social animals that usually swim in large pods of at least 100 and are not commonly seen around Kauai. Instead, the lone melon-headed whale and the hybrid were found swimming near a group of rough-toothed dolphins.
The researchers were able to take a biopsy and confirmed Friday in a new report that the creature was the first known hybrid between a melon-headed whale and a rough-toothed dolphin. Or as some have called it, a "wholphin."
The genetic research indicated the male hybrid was likely a product of a female melon-headed whale and a male rough-toothed dolphin mating together.
Baird told BuzzFeed News that they are heading back to Kauai in August and hope to find the pair again, so that they can determine whether the female melon-headed whale is the mother of the hybrid and to get better underwater photos of the hybrid "to better assess morphological differences from the parent species."
But while melon-headed whales are called "whales," they are really part of the dolphin family. The Delphinidae family also includes other creatures usually not thought of as dolphins, like pygmy killer whales, false killer whales, pilot whales, and orcas, which are all known as "blackfish." This has led some people to point out that calling the new creature a "wholphin" is just wrong.
Baird told BuzzFeed News that it is important to note that "the hybridization is between two species of dolphins," and one of them "just happens to have 'whale' in the common name."
"The term 'whale' was historically applied to a number of medium- and large cetaceans, before the taxonomic relationships were well understood," Baird said.
People have had all sorts of *feelings* about the underwater discovery.
Cascadia Research seemed to enjoy the many takes on the hybrid animal, sharing some memorable headlines and tweets on its Facebook page:
According to the group's report, the animal is only the third known wild-born hybrid between two different species in the Delphinidae family, making it a pretty significant discovery no matter what you call it.
The report said the discovery lends support to the hypothesis that "introgressive hybridization" — in which genetic data from one species integrates into the genome of another species following hybridization — causes taxonomic uncertainty in the Delphinidae family.
Marc Lammers, who is an affiliate faculty member at the Hawaii Institute of Marine Biology, told BuzzFeed News that hybrids in nature are not that rare.
"In plants it is very common," Lammers said about the frequency of hybrids. "In animals less so, but probably happens more than we think, especially among closely related species. It only catches people's attention more when it occurs among more distantly related or morphologically distinct species."
Previously, a hybrid between a common bottlenose dolphin and an Indo-Pacific bottlenose dolphin was reported in waters around Hawaii, and hybrids between two species of porpoises have also been found around Washington state. The most recent discovery is the first known pairing of a melon-headed whale and a rough-toothed dolphin.