Belugas possess a remarkable ability to find open stretches of water in the Arctic pack ice, enabling them to surface and breathe in this environment. Beluga means "white" in Russian, so these whales are sometimes called white whales. However, they should not be confused with white sturgeon - large fish that produce beluga caviar. Beluga whales are also nicknamed sea canaries, because they call to each other with high-pitched trills. It has a rounded, plump body and just a hint of a beak. There is a short raised ridge along its back where the dorsal fin would normally be. They have about 32 teeth.
Beluga whales live in the far north, where daylight is very brief or non-existent much of the year. They may occasionally congregate in large groups numbering several thousand, although they generally live in pods made up of a dozen or so individuals. Some beluga whale pods, or schools, spend all their time in one area of ocean, such as the Gulf of St Lawrence; others are always on the move. The pods are ruled by large males, and all pods spend their winters away from areas of thick ice. Beluga whales are often seen in shallow coastal waters, sometimes even at the mouths of rivers, although they have been recorded diving to depths of 1000 m (3280 ft). In summer, they enter river estuaries and shallow bays.
Adult beluga whales are almost completely white, helping them to hide among ice floes. Younger whales begin life with dark bodies, which gradually become yellow and brown before fading to white.
Beluga whales navigate using a well-developed sonar system, which is thought to be controlled by the melon - the large sensory organ on top of the head. Their lifestyle varies according to their location, with some populations being migratory, a fact revealed by satellite tracking. Five distinct and separate groups have been identified through their extensive range.
Sexual maturity is attained when the whales are between 5 and 8 years old. The whales mate in spring and calves are born in the summer after a gestation period of about 14 months. Since the young are suckled for at least a year, beluga whales are able to breed only every 3 years or so.
Distribution: Occurs in the seas of the far north, having a circumpolar distribution through the Arctic region, extending as far south as Hudson Bay in Canada.
Habitat: Deep coastal waters and mouths of large rivers.
Weight: 900 - 1500 kg (1984 - 3306 lb); Males are bigger.
Length: 3.5 - 5.5 m (12 - 18 ft).
Maturity: Females 5 years; males 8 years.
Gestation Period: Around 465 days.
Breeding: 1; weaning may last for 2 years.
Diet: Fish such as capelin, salmon, Arctic char and cod, as well as squid, octopus and marine worms.
Lifespan: Over 50 years.
The cervical vertebrae are not fused, allowing beluga whales to turn their heads from side to side.
Adults turn white at around seven to nine years; females change first.
There is no dorsal fin on the back. The beluga's generic name Delphinapterus means "dolphin without a fin".
Young beluga whales are greyish-cream at birth, soon becoming bluish-grey.
Polar bears represent a significant danger to belugas and especially to young calves, seizing them when they surface for air.
The "melon" on the head emits sound waves.