The earliest discovered anatomically modern blue whale is a partial skull fossil found in southern Italy, dating to the Early Pleistocene, roughly 1.5–1.25 million years ago. A 2018 analysis estimates that the Balaenopteridae family diverged from other families in between 10.48 and 4.98 million years ago during the late Miocene. Evolution BalaenopteridaeĪ phylogenetic tree of six baleen whale species īlue whales are rorquals in the family Balaenopteridae. Herman Melville called the blue whale "sulphur bottom" in his novel Moby Dick because of the accumulation of diatoms creating a yellowish appearance on their pale underside. īlue whales were referred to as 'Sibbald's rorqual', after Robert Sibbald, who first described the species. Sars adopted it as the common name in 1874. The name "blue whale" was derived from the Norwegian "blåhval", coined by Svend Foyn shortly after he had perfected the harpoon gun. One of the first published descriptions of a blue whale comes from Robert Sibbald's Phalainologia Nova, after Sibbald found a stranded whale in the estuary of the Firth of Forth, Scotland, in 1692.
The genus name, Balaenoptera, means winged whale while the species name, musculus, could mean "muscle" or a diminutive form of "mouse", possibly a pun by Carl Linnaeus when he named the species in Systema Naturae. See also: Evolution of cetaceans Nomenclature
It continues to face numerous man-made threats such as ship strikes, pollution, ocean noise and climate change. The International Union for Conservation of Nature has listed blue whales as Endangered as of 2018. It was hunted almost to the point of extinction by whalers until the International Whaling Commission banned all blue whale hunting in 1966. The blue whale was once abundant in nearly all the Earth's oceans until the end of the 19th century. The fundamental frequency for blue whale vocalizations ranges from 8 to 25 Hz and the production of vocalizations may vary by region, season, behavior, and time of day. They are generally solitary or gather in small groups, and have no well-defined social structure other than mother-calf bonds. Blue whales are filter feeders their diet consists almost exclusively of krill. There is also evidence of year-round residencies, and partial or age/sex-based migration. In general, blue whale populations migrate between their summer feeding areas near the poles and their winter breeding grounds near the tropics. There is also a population in the waters off Chile that may constitute a fifth subspecies. brevicauda (the pygmy blue whale) in the Indian Ocean and South Pacific Ocean, B. musculus in the North Atlantic and North Pacific, B. The blue whale's long and slender body can be of various shades of greyish-blue dorsally and somewhat lighter underneath.
Reaching a maximum confirmed length of 29.9 meters (98 ft) and weighing up to 199 tonnes (196 long tons 219 short tons), it is the largest animal known ever to have existed. The calf is suckled in the water, drinking more than 600 litres of milk each day and gaining about 90kg every day for its first year.The blue whale ( Balaenoptera musculus) is a marine mammal and a baleen whale.New born whales are helped to the surface of the water by their mothers and are often encouraged (nudged) by other females so that they can take their first breath of air. A baby blue whale (calf) emerges weighing up to 2,7000kg and up to 8m long.
Females breed only once every three years and gestation is between 11-12months.When it surfaces, it exhales air out of a blowhole in a cloud of pressurized vapour that rises vertically above the water for up to 9m. Although the blue whale is a deep-water hunter, as a mammal, it must come to the surface of the sea to breathe.Having forced the water out of its mouth, the whale licks these bristles with its fleshy tongue. With each mouthful, the whale can hold up to 5,000 kg of water and plankton. There is what looks like a moustache of long bristles on the end of each plate to help it hold the minute prey. The whale’s mouth has a fascinating row of plates fringed with bristles to help it filter its main source of food – plankton from the water.
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