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Blue Whale

  • Blue Whale
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The Blue Whale (Balaenoptera musculus) is the largest animal documented so far to ever have existed on earth. It has a wide distribution occurring in all the oceans of the world in three distinctive subspecies; B. m. musculus (Northern Hemisphere Blue Whale), B. m.intermedia (Antarctic Blue Whale) and B. m. brevicauda (Pygmy Blue Whale). The Blue Whales recorded around Sri Lanka reportedly belong to the Pygmy Blue Whale subspecies. However, Brown and Donahue (1994) say that the northern Indian Ocean populations of Blue Whale should be recognised as a separate subspecies, B. m. indica

During the fall and winter months these cetaceans make long migrations to the tropics from the temperate zones to calve and breed. However it is an idea that Sri Lanka has its own resident pods of Blue Whale, which are found around the waters off the island right throughout the year, but further scientific studies have to be carried out to justify this idea.

Scientific Classification

Balaenoptera musculus
  • Scientific Name :
  • Balaenoptera musculus
Animals
  • Kingdom :
  • Animals
Mammalia
  • Class :
  • Mammalia
Cetartiodactyla
  • Order :
  • Cetartiodactyla
Balaenopteridae
  • Family :
  • Balaenopteridae
Balaenoptera
  • Genus :
  • Balaenoptera
Musculus
  • Species :
  • Musculus

Quick Facts

up to 200 tons
  • Weight:
  • up to 200 tons
up to 30 meters
  • Size:
  • up to 30 meters
Other
  • Diet:
  • Other
North Atlantic,North Pacific,Southern Hemisphere,Northern Indian Ocean
  • Locations:
  • North Atlantic,North Pacific,Southern Hemisphere,Northern Indian Ocean
Increasing
  • Population Trend:
  • Increasing
Endangered
  • Conservation Status:
  • Endangered

  • Physical Description

    The Blue Whale grows to about 23-33 metres in length and weighs around 200 tonnes (depending on the subspecies). It is easily set apart from it congeners by the large size, the stubbly dorsal fin and it grayish-blue hue with mottling of light grey. It has 55-88 ventral plates, which aids them when feeding. They have about 200-400 baleen plates hanging from each side of the jaw, these baleen plates are black in colour.

  • Biology

    Though large in size, the Blue Whale feeds on one of the smallest organisms in the world “euphausiid crustaceans”, due to their large size, Blue Whale require large concentrations of food, and feed on about four tonnes of krill a day. They feed by lunging forward at a concentration of krill, taking the animals and a large quantity of water into the mouth. The water is then squeezed out through the baleen plates by pressure from the ventral pouch and tongue. Once the mouth is clear of water, the remaining krill which are sieved by the baleen plates are swallowed.

  • Habitat and Distribution

    Blue whale migration patterns are not very well known or understood, but seem to be quite diverse. Some populations undertake long migrations to high-latitude feeding grounds while others, like the population found in Sri Lanka, appear to be resident year-round in habitats that show high productivity throughout the year.

  • Threats and Conservation

    At the turn of the twentieth century Blue Whales were targeted by the whaling industry for its meat and oil, as its sheer size proved advantages to the whalers as it yielded a high content of meat and oil, which lead them to hunt this species to near extinction.

    Since the ban on hunting Blue Whales, populations are slowly recovering. However, their survival continues to be threatened as they are now faced with modern day threats as vessel strikes, fisheries interaction, anthropogenic noise, habitat degradation, pollution.