Beluga and Narwhal are native to coastal regions and pack ice around the Arctic Ocean.

Both species are relatively small whales, 3–5 m (9.8–16.4 ft) in length, with a forehead melon, and a short or absent snout.

[1] They do not have a true dorsal fin, but do have a narrow ridge running along the back, which is much more pronounced in the narwhal.

Monodontids have a wide-ranging carnivorous diet, feeding on fish, molluscs, and small crustaceans.

Genetic evidence suggests the porpoises are more closely related to the white whales, and these two families constitute a separate clade which diverged from the Delphinidae within the past 11 million years.