The beluga's body is stout and has a small, blunt head with a small beak, tiny eyes and thick layers of blubber. On their head they have a round shape called the melon. This melon holds oil, and the whale is able to change its shape. Scientists believe that it has something to do with the whale's echolocation system. They have one blowhole. Beluga means "white one" in Russian. Its genus Delphinapterus, means "whale without fins", and the species, "leucas", means "white". The beluga is also called the white whale, the white porpoise, the sea canary (because of its songs), and the squid hound (due to its diet). Unlike most other cetaceans, the beluga's seven neck vertebrae are not fused, giving it a flexible, well-defined neck.