Blue Whale: The Biggest Animal In The World..




The blue whale (Balaenoptera musculus) is a marine mammal belonging to the baleen whales (Mysticeti). At up to 29.9 metres (98 ft) in length and with a maximum recorded weight of 173 tonnes (190 short tons) and probably reaching over 181 tonnes (200 short tons), it is the largest animal known to have ever existed.
Long and slender, the blue whale's body can be various shades of bluish-grey dorsally and somewhat lighter underneath.
There are at least three distinct subspecies: B. m. musculus of the North Atlantic and North Pacific, B. m. intermedia of the Southern Ocean and B. m. brevicauda (also known as the pygmy blue whale) found in the Indian Ocean and South Pacific Ocean. B. m. indica, found in the Indian Ocean, may be another subspecies. As with other baleen whales, its diet consists almost exclusively of small crustaceans known as krill.
Blue whales are rorquals (family Balaenopteridae), a family that includes the humpback whale, the fin whale, Bryde's whale, the sei whale, and the minke whale. The family Balaenopteridae is believed to have diverged from the other families of the suborder Mysticeti as long ago as the middle Oligocene (28 Ma ago). It is not known when the members of those families diverged from each other.
The blue whale has a long tapering body that appears stretched in comparison with the stockier build of other whales.The head is flat, U-shaped and has a prominent ridge running from the blowhole to the top of the upper lip.The front part of the mouth is thick with baleen plates; around 300 plates, each around one metre (3.3 feet) long,hang from the upper jaw, running 0.5 m (20 in) back into the mouth. Between 70 and 118 grooves (called ventral pleats) run along the throat parallel to the body length. These pleats assist with evacuating water from the mouth after lunge feeding.


The dorsal fin is small; its height averages about 28 centimetres (11 in), and usually ranges between 20 and 40 cm (7.9 and 15.7 in), though it can be as small as 8 cm (3.1 in) or as large as 70 cm (28 in). It is visible only briefly during the dive sequence.
When breathing, the whale emits a vertical single-column spout, typically 9 metres (30 ft) high, but reaching up to 12 metres (39 ft). Its lung capacity is 5,000 litres (1,300 US gal). Blue whales have twin blowholes shielded by a large splashguard.
Blue whales can reach speeds of 50 kilometres per hour (31 mph) over short bursts, usually when interacting with other whales, but 20 kilometres per hour (12 mph) is a more typical traveling speed.
The total world population was estimated to be between 5,000 and 12,000 in 2002; there are high levels of uncertainty in available estimates for many areas. A more recent estimate by the IUCN puts the global population at 10,000–25,000.

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