The Blue Whale

(Balaenoptera musculus)

The Blue whale is, and always has been, the largest animal ever to exist on earth. This whale can grow to a length of 33m (110ft) and weigh 190 tonnes but on the average it is much smaller. The Blue whale is called a "rorqual" a Norwegian word for "furrow" and refers to the pleated grooves running from its chin to its navel. The throat grooves, in addition to streamlining the shape of the whale, allow the throat area (cavum vent-rale) to expand tremendously during feeding, and can hold 1,000 tons or more of food and water when fully expanded. By taking tonnes of water into its mouth and filtering out the fish or krill with its baleen plates a medium-sized Blue whale can eat over 4 tons of krill a day.

Blue whale image

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The head of the Blue whale forms up to a quarter of the total body length and compared with other rorquals is very broad. It has twin blowholes with exceptionally large fleshy splashguards to the front and sides. The baleen plates in the mouth of the Blue whale can be 90cm-1m (35-39in) in length the longest of all the rorquals but not the longest of all whales.

Family: Balaenopteridae

Subfamily: Balaenopterinae

There are 3 different subspecies:

balaenoptera musculus - Northern Hemisphere
balaenoptera intermedia - Southern Hemisphere
balaenoptera brevicauda - Tropical Southern Hemisphere

Other Names: Sulphur-bottom, Sibbald's Rorqual, Great Northern Rorqual

Most Blue whales live in the Southern Hemisphere while smaller populations inhabit the North Atlantic and North Pacific. They migrate long distances between low latitude winter mating grounds and high latitude summer feeding grounds and are often seen in parts of California, Gulf of California (Sea of Cortez), Gulf of St. Lawrence, Canada and the northern Indian Ocean.

Before mans intervention there were 228,000 Blue whales swimming the oceans of the world. Between 1904 and 1978, whalers scoured the seas for this huge cetacean, most were taken in the southern hemisphere, many against the law. Current figures suggest that a mere 11,700 animals are left. As the population figure suggests, it was ruthlessly and relentlessly slaughtered for every reason imaginable, almost to the point of extinction. Now on the endangered list, the Blue Whale is protected (since 1967) worldwide by international law. It is not to be hunted by anyone for any reason at all. Suggestion are that some populations may never recover.

Bibliography Whales on the Net

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