Blue whale

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Blue whale
Temporal range:
Middle Pleistocene – recent
Anim1754 - Flickr - NOAA Photo Library.jpg
Adult blue whale
(Balaenoptera musculus)
Blue whale size.svg
Size compared to an average human
Scientific classification e
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Order: Artiodactyla
Infraorder: Cetacea
Family: Balaenopteridae
Genus: Balaenoptera
Species:
B. musculus
Binomial name
Balaenoptera musculus
Subspecies
  • B. m. brevicauda Ichihara, 1966
  • ?B. m. indica Blyth, 1859
  • B. m. intermedia Burmeister, 1871
  • B. m. musculus Linnaeus, 1758
Cypron-Range Balaenoptera musculus.svg
Blue whale range (in blue)
Synonyms
  • Balaena musculus Linnaeus, 1758
  • Balaenoptera gibbar Scoresby, 1820
  • Pterobalaena gigas Van Beneden, 1861
  • Physalus latirostris Flower, 1864
  • Sibbaldius borealis Gray, 1866
  • Flowerius gigas Lilljeborg, 1867
  • Sibbaldius sulfureus Cope, 1869
  • Balaenoptera sibbaldii Sars, 1875

The blue whale (Balaenoptera musculus) is a marine mammal of the suborder of baleen whales (called Mysticeti). They grow to be about 30 meters long. The biggest blue whale found was 190 tons and measured 98 feet long.[3][4] Larger specimens have been measured at 110 feet, but never weighed. This makes blue whales the largest animals ever to be on Earth, even bigger than the largest dinosaurs.

The blue whale eats mostly very tiny creatures, like krill. These inch-long, shrimp-like crustacean swim in swarms. In the Antarctic summer, there are so many of these krill that they turn the waters orange. A blue whale can eat eight to ten tons of krill every day.[5]

The blue whale's body is long and slender. It can be various shades of bluish-grey above and somewhat lighter underneath.[6] 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 krill.[7]

Blue whales were once abundant around the world. In the nineteenth century, they were hunted almost to extinction by whalers. They were finally protected by the international community in 1966. A 2002 report estimated there were 5,000 to 12,000 blue whales worldwide,[8] located in at least five groups. More recent research into the Pygmy subspecies suggests this may be an underestimate.[9] Before whaling, the largest population was in the Antarctic, numbering approximately 239,000 (range 202,000 to 311,000).[10] There remain only much smaller (around 2,000) concentrations in each of the eastern North Pacific, Antarctic, and Indian Ocean groups. There are two more groups in the North Atlantic, and at least two in the Southern Hemisphere.

References[change | change source]

  1. Reilly, S. B.; Bannister, J. L.; Best, P. B.; Brown, M.; Brownell Jr., R. L.; Butterworth, D. S.; Clapham, P. J.; Cooke, J.; Donovan, G. P.; Urbán, J. & Zerbini, A. N. (2008). "Balaenoptera musculus". The IUCN Red List of Threatened Species. 2008: e.T2477A9447146. doi:10.2305/IUCN.UK.2008.RLTS.T2477A9447146.en.
  2. "Species Profile". ecos.fws.gov. Retrieved 6 February 2020.
  3. Calambokidis, J.; Steiger, G. (1998). Blue whales. Voyageur Press. ISBN 0-89658-338-4.
  4. "Animal Records". Smithsonian National Zoological Park. Retrieved 29 May 2007.
  5. Piper, Ross 2007. Extraordinary Animals: An encyclopedia of curious and unusual animals. Greenwood Press.
  6. "Species Fact Sheets: Balanoptera musculus (Linnaeus, 1758)". Fisheries and Aquaculture Department, Food and Agriculture Organization, United Nations. Retrieved 2012-12-24.
  7. Jason de Koning and Geoff Wild (1997). "Contaminant analysis of organochlorines in blubber biopsies from blue whales in the St. Lawrence Seaway". Trent University. Archived from the original on 2017-03-28. Retrieved 2007-06-29.
  8. "Assessment and Update Status Report on the Blue Whale Balaenoptera musculus" (PDF). Committee on the Status of Endangered Wildlife in Canada. 2002. Retrieved 2007-04-19.
  9. Alex Kirby (19 June 2003). "Science seeks clues to pygmy whale". BBC News Online. Retrieved 21 April 2006.
  10. T.A. Branch, K. Matsuoka and T. Miyashita (2004). "Evidence for increases in Antarctic blue whales based on Bayesian modelling". Marine Mammal Science. 20 (4): 726–754. doi:10.1111/j.1748-7692.2004.tb01190.x.