Beluga whale


The Beluga Whale or the White Whale is an Arctic and sub-Arctic ‘cetacean’.  This marine animal is commonly referred to as ‘melon-head’, ‘beluga’ or ‘sea-canary’ (due to its high-pitched twitter).
Delphinapterus_leucas_2

It is adapted to life in the Arctic, so has ‘anatomical’ and ‘physiological’ characteristics that differentiate it from other ‘cetaceans’.  Amongst those are its unmistakable all-white colour and an absence of a ‘dorsal fin’.  It possesses a distinctive protuberance at the front of its head called the ‘melon’, which, in this species, is large and deformable.  The beluga’s body size is between that of a dolphin’ and a ‘true whale’, with the males growing up to 18ft long and weighing up to 1,600kg.  It has a stocky body, and the greatest percentage of ‘blubber’.  Its sense of hearing is highly developed and it possesses ‘echolocation’, which allows it to move about and find blow-holes under ‘sheet ice’.  It can hear sounds of 1.2 kHz to 120 kHz.  The majority of sounds are received by the lower jaw and transmitted towards the middle ear.  They are able to see ‘within’ and ‘outside’ of water, but their vision is relatively poor when compared to dolphins.  Their eyes are especially adapted to seeing under water, although, when they come into contact with air, the ‘crystalline lens’ and the ‘cornea’ adjust to overcome the associated ‘myopia’.

Beluga whale, White sea, Russia, Kareliya

Its body is round, when well fed, and tapers less smoothly to the head than the tail.  The sudden tapering to the base of the neck gives it the appearance of shoulders, UNIQUE AMONG CETACEANS.  The tail fin grows and becomes increasingly and ornately curved as the animal ages.  The flippers are broad and short, making them almost square-shaped.  The males are 25% longer than the females and are sturdier.  Between 40% to 50% of their body weight is ‘fat’, which acts as insulation in waters with temperatures between 0 degrees and 18 degrees, as well as being an important reserve during periods when there is no food.

beluga-whale-bubble_782215i

Female belugas give birth to one calf every three years.  Calves are usually born grey and by the time they are a month old turn dark grey or blue grey.  They then start to lose their pigmentation until they attain their ‘distinctive white colouration’ at the age of seven years (in females) and nine years (in males).
They can dive to great depths, with the greatest recorded depth being 872m.  A dive normally lasts 3-5mins, but they can also last up to 15-18mins.  They have physiological adaptions designed to conserve oxygen while they are under water.  During a dive, they will ‘reduce their heart-rate’ from 100 beats a minute to between 12 and 20 beats a minute.

Beluga-Whale-6

The beluga was first described in 1776 by Peter Simon Pallas.  The name of the genus ‘DELPHINAPTERUS’ means “dolphin without fin’ (from the Greek ——‘delphin’ (dolphin) and ‘apteros (without fin) and the species’ name ‘leucas’ (white).  The beluga is also known as the ‘sea canary’ on account of its high-pitched squeaks, squeals, clucks and whistles.  NOC, a beluga whale could mimic the rhythm and tone of human language.
Belugas are very gregarious and they form groups (pods) of up to 10 animals on average, although during the summer months, they can gather in 100s and even 1000s in estuaries and shallow coastal areas.  They seek regular physical contact with other belugas.

baby beluga whale

The majority of belugas live in the Arctic and seas and coasts around North America, Russia and Greenland, and their world-wide population is thought to number around 150,000.  They are migratory and the majority of groups spend the winter around the Arctic ice-cap.  When the sea ice melts, in summer, they move to warmer river estuaries.
They are ‘opportunistic’ feeders and mainly eat fish, crustaceans and other deep-sea invertebrates.
The natives of North America and Russia have hunted belugas for many centuries.  They were also hunted commercially during the 19th century and part of the 20th century.  “Whale hunting’ has been under International control since 1973.  Currently, only certain Inuit groups are allowed to carry out ‘subsistence’ hunting of belugas.  Other threats include polar bears and killer whales.  From a conservation perspective, the beluga was placed on the International Union for Conservation of Nature’s “RED LIST” in 2008 as being ‘near threatened’.  Belugas are most commonly kept in captivity in ‘aquariums’ and ‘wildlife parks’, and are popular with the public due to their ‘colour’ and ‘expressions’.
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