The beluga whale is the only species of whale that is entirely white, but they are born gray and gradually fade to white with age.
The beluga whale is the only species of whale that is entirely white. The white coloration may provide camouflage amongst snow and ice, as observations of killer whale attacks on belugas show that belugas attempt to hide amongst sea ice to avoid predation.
The white color for which belugas are named does not appear until an animal reaches maturity. Beluga calves are born a light brown-grey color, which darkens and fades gradually with age before turning the characteristic white. The change in color is not related to sexual maturity, although these events may occur at the same time.
In adults, a dark pigment is often present on the top of the dorsal ridge and along the edges of the flukes and pectoral flippers.