One of the delightful things about crossbreeding between different species is the bonkers names sometimes chosen for the hybrid offspring.
Think of the grolar bear (a cross between a male grizzly bear and a female polar bear) or pizzly bearif the parents were the other way around and the liger (when a male lion breeds with and a female tiger) or tigon (vice versa).
We know that several different species on land can interbreed, but what about animals in the ocean? Might it be possible for a whale and a dolphin to produce a hybrid – and if so, could there be little dolwhales, humporcas or narlugas swimming around in our seas?
Firstly, it’s important to point out that the distinction between whales and dolphins is a slightly tricky one. Whales, dolphins and porpoises are all part of a group of fully aquatic marine mammals called cetaceans: there are around 90 different species from the gigantic blue whale to the humble (and highly endangered) vaquita.
Cetaceans can be split into two main types: baleen whales (which have a sieve-like structure within their mouth to catch tiny fish when they take a gulp of water) and toothed whales (which eat prey using – you guessed it – their teeth).
Dolphins fall into the toothed whale category – so all dolphins are, in a sense, whales. But not all whales (or even all toothed whales) are dolphins. To make it more baffling, several toothed whales with “whale” in their common name are, technically, dolphins: killer whales, pilot whales and melon-headed whales are all among these confusing examples.
But, with that straight, could a species of dolphin successfully breed with a whale? And are any types of cetaceans closely related enough to breed with another?
Sort of. A wonderfully whimsical named “wholphin” baby was reportedly born in Tokyo SeaWorld in 1981. Although the name wholphin stuck, both its parents – a bottlenose dolphin and a false killer whale – were species of dolphin. The baby sadly died before it was one year old.
Another wholphin was born in captivity in 1985: this time in Sea Life Park, Hawai’i. Named, Kekaimalu, she seemed to be a perfect blend of her parents: larger and darker skinned than her bottlenose dolphin mother yet smaller and paler than her false killer whale father. Oh, and she had 66 teeth (bottlenose dolphins have 88, false killer whales have 44). Although hybrid offspring aren’t always fertile, it’s said that Kekaimalu had three babies of her own.
In the wild, false killer whales and bottlenose dolphins have been seen hanging out but there’s no confirmed scientific evidence of interbreeding to date. That’s not to say it’s not ever happened – perhaps scientists just haven’t come across the hybrid calves yet.
There have been other wild hybrids born to cetacean parents of different species – although it’s rare.
Take the 2017 sighting of a weird-looking animal swimming with a pod of rough-toothed dolphins in Kauaʻi, Hawaiʻi. The individual turned out to be a hybrid between a rough-toothed dolphin and melon-headed whale. Remember, these are among the “whale” species that aren’t really whales so, although this was a scientific first, it wasn’t a wholphin.
Or the skull found in West Greenland in 1990 that was later confirmed to be the offspring of a narwhal and a beluga whale; a narluga, if you will (pleasingly, that is what it’s been called). “Our analyses reveal that the specimen is a male, first-generation hybrid between a female narwhal and a male beluga,” wrote the authors in the Scientific Reports study. It was, they say, “the sole evidence of hybridisation between the only two toothed whale species endemic to the Arctic.”
And there are also flue whales (the sometimes fertile offspring of fin and blue whales) now roaming the ocean.
Although there is evidence of babies being born between different species of dolphins and, separately, between different species of whales, there hasn’t yet been a true wholphin confirmed by science. Which is a shame because the discovery of a narwhorca or a humpolphin would be pretty cool.
