Beluga Whale or White Whale (Delphinapterus leucas)
Reference work entry
Beluga whale or White Whale (Delphinapterus leucas) – a big mammal of the cetacean family Delphinidae, suborder Odontoceti (toothed whale), which is sometimes called “a polar dolphin.” Its body length reaches 6 m and weighs 1.5 tons. The color of an adult B. is white which explains the name. It is spread in the circumpolar regions inhabiting the Arctic and adjacent seas. Within the Arctic sea region, there are two subspecies: the Kara B. and the Pacific Ocean B. It is well adapted to life among the ice. Its skin is completely devoid of hair but is protected by a thick (up to 2 cm) layer of epidermis. On the head, there is a thick fatty “pad” which allows the animal to wedge away or break the light ice. B. eats fish (capelin, polar cod, salmon fishes, herrings, etc.), shellfishes, and mussels. Hunting for fish it enters big rivers (the Ob, Yenisei, Lena, Amur, etc.), sometimes going 1,000 km and more up the stream, with lives in stocks having the population ranging from several dozens to a thousand. In winter, B. does not stay in the Laptev Sea, is prone to seasonal migrations, and reaches maturity when it is 2–3 years old. The female gives birth to one, rarely two, calf. It has great importance in trading and is valued for its fat (gives 250–400 kg), meat, and skin (up to 9 m2). Moreover, it has costly bone fat, which is used for lubrication. Year 2008 saw the launch of the program of studying, distribution, and population of B. in the Russian Arctic by means of aviation and vessel observation. The scientists trace their migrations with the help of a radio beacon of the system ARGOS, study the population structure of B. with the help of molecular and genetic diagnostics, and evaluate the state of the animal health and the impact of different anthropogenic factors on them.
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