Every now and again, Mother Nature reveals a delightful surprise in the form of something unusual and remarkable. One such extraordinary occurrence is the recent discovery of an extremely rare hybrid between a melon-headed whale and a rough-toothed dolphin. The mammal was first sighted in August 2017 by a group of researchers on a two-week expedition to document marine life off the coast of Kauai, Hawaii.
The Cascadia Research Collective scientists were observing a pod of rough-toothed dolphins when they noticed, what appeared to be, two specimens of melon-headed whales. Upon looking closer, they realized that one of the two “whales” looked a little different. The animal had a melon-headed whale’s dorsal fin and dorsal cape but a rough-toothed dolphin’s blotchy pigmentation and sloping forehead. Close-up pictures appeared to indicate that the researchers had stumbled upon a hybrid of the two species.
To confirm their suspicions, the scientists used a crossbow, equipped with a special dart, to extract the mammal’s skin sample without harming it. They then compared the DNA in the tissue to the genetic data of the two species collected by scientists over many years. In a report published in July 2018, the team confirmed that the odd-looking male was indeed the offspring of a melon-headed whale mother and a rough-toothed dolphin father. The researchers suspect the whale observed swimming alongside the hybrid is most likely its mom. They speculate she got separated from its pod and decided to join the rough-toothed dolphins.
This is the fourth-known hybrid of the Oceanic dolphins, or Delphinidae, and the only one found in the wild. The first specimen was born at Tokyo’s Kamogawa SeaWorld but died within 200 days. Fortunately, Kekaimalu, the offspring of a false killer whale and a bottlenose dolphin, born at Hawaii’s Sea Life Park is healthy and even mated with a male bottle-nose dolphin to give birth to another hybrid female, "Kawili Kai.”
While the hybrids are commonly referred to as “wholphins,” the scientists say the moniker is misleading. That’s because though we may think of whales and dolphins as different species, they are all Oceanic dolphins. Therefore, the latest find is just a hybridization between two different species of dolphins. “Calling it something like a wholphin doesn’t make any sense,” says research biologist and the study’s lead author Robin Baird. “I think calling it a wholphin just confuses the situation more than it already is.”
The team is also reluctant to classify the specimen as a new species since lone hybrids are often unable to reproduce. For a new species to emerge, hybridization would have to occur much more frequently, and the hybrids would have to be able to reproduce and prefer to breed with one another. Regardless, the team is excited about the discovery and plan to head back to Kauai to research the hybrid further, and also test the DNA of the melon-headed whale in the pod to confirm if she is indeed the mother.
Resources: Businessinsider.com, theguardian.com, Interestingengineering.com