Scientists have spotted a new hybrid dolphin in the waters of Hawaii. You might have seen reports describing it as a "rare whale/dolphin hybrid", but it is actually the result of breeding between two species of dolphin. Nevertheless, the find is still very exciting, and is a first-of-its-kind discovery. 

The dolphin was spotted off the coast of Kauai, and is half rough-toothed dolphin and half melon-headed dolphin. This is where the confusion lies – melon-headed dolphins are also known as melon-headed whales, but really, they are dolphins. In fact, many species of toothed whale, such as pilot whales and killer whales, are technically dolphins. However, not all toothed whales are dolphins, like sperms whales and porpoises. Larger whales like blue, gray, and humpback whales do not have teeth, and are classed as baleen whales, thanks to the large plates in their mouths called baleen that they use to filter-feed.

Back in August 2017, a team from the Cascadia Research Collective was assessing the wildlife in the waters around the US Navy’s Pacific Missile Range Facility in preparation for a military training. And they were pretty surprised by what they saw.

Swimming alongside a pod of rough-toothed dolphins the researchers spotted a creature that didn’t look quite right. It had an unusual beak and abnormal coloration. They suspected it might be a hybrid and managed to obtain a skin sample to find out. After looking at the animal’s DNA they concluded that it was indeed part melon-headed dolphin and part rough-toothed dolphin, something that has never been witnessed before. They even worked out that it had a rough-toothed dad and a melon-headed mom.

The researchers think they might have spotted the mom, as they witnessed the hybrid and a lone melon-headed dolphin swimming with the rough-toothed dolphins.

Melon-headed dolphins tend to be found in groups of over 200, but the researchers saw no other members of the species during this particular sighting. Therefore, it seems the hybrid’s mom might be having a bit of an identity crisis, choosing to spend her time with her rough-toothed relatives. However, as biologist Robin Baird pointed out to HuffPost, perhaps this isn’t all that bizarre.

“I wouldn’t be surprised if there are more hybrids between the two species – they do associate quite regularly,” he said.

While the new hybrid is unique, it’s unlikely to actually be a new species. Creatures have to meet a number of criteria to be considered a new species, one of which is the ability to reproduce, and hybrids are often infertile. However, it’s not impossible – the Clymene dolphin is a hybrid species resulting from breeding between spinner and striped dolphins.

So, while the rough-toothed melon-headed dolphin might not be its own species, it provides an intriguing new insight into the social interactions of cetaceans. And there could be many other hybrid marine creatures out there, we just haven’t spotted them yet.