BALEEN is a filter-feeder system inside the mouths of baleen whales .
The baleen system works by a whale opening its mouth underwater and
taking in water. The whale then pushes the water out, and animals such
as krill are filtered by the baleen and remain as food source for the
Depending on the species, a baleen plate can be 0.5 to 3.5 metres
(1.6 to 11.5 ft) long, and weigh up to 90 kilograms (200 lb). Its
hairy fringes are called baleen hair or whalebone-hair. They are also
called baleen bristles, which in sei whales are highly calcified,
calcification functioning to increase their stiffness.
* 1 Etymology * 2 Evolution * 3 Filter feeding * 4 Human uses * 5 As a habitat * 6 See also * 7 References * 8 Further reading * 9 External links
The word baleen derives from the Latin bālaena, related to the Greek phalaina – both of which mean "whale".
The oldest true fossils of baleen are only 15 million years old
because baleen rarely fossilizes, and scientists believe it originated
considerably earlier than that. This is indicated by baleen-related
skull modifications being found in fossils from considerably earlier,
including a buttress of bone in the upper jaw beneath the eyes, and
loose lower jaw bones at the chin.
The transition from teeth to baleen is proposed to have occurred
stepwise , from teeth to a hybrid to baleen. It is known that modern
mysticetes have teeth initially and then develop baleen plate germs in
utero, but lose their dentition and have only baleen during their
juvenile years and adulthood. However, developing mysticetes do not
produce tooth enamel because at some point this trait evolved to
become a pseudogene . This is likely to have occurred about 28 million
years ago and proves that dentition is an ancestral state of
mysticetes. Using parsimony to study this and other ancestral
characters suggest that the common ancestor of aetiocetids and
edentulous mysticetes evolved lateral nutrient foramina , which are
believed to have provided blood vessels and nerves a way to reach
developing baleen. Further research suggests that the baleen of
If it is true that many early baleen whales also had teeth, these were probably used only peripherally, or perhaps not at all (again like Dall\'s porpoise , which catches squid and fish by gripping them against its hard upper jaw). Intense research has been carried out to sort out the evolution and phylogenetic history of mysticetes, but there is still much debate surrounding this issue. More work needs to be done to characterize extinct ancestral fossils so that future scientists will be able to piece together a more accurate phylogenetic tree.
A whale's baleen plates play the most important role in its filter-feeding process. In order to feed, a baleen whale opens its mouth widely and scoops in dense shoals of prey (such as krill , copepods , small fish and sometimes birds that happen to be near the shoals), together with large volumes of water. It then partly shuts its mouth and presses its tongue against its upper jaw, forcing the water to pass out sideways through the baleen, thus sieving out the prey which it then swallows.
People formerly used baleen (usually referred to as "whalebone") for making numerous items where flexibility and strength were required, including backscratchers , collar stiffeners , buggy whips , parasol ribs, crinoline petticoats and corset stays . It was commonly used to crease paper ; its flexibility kept it from damaging the paper. It was also occasionally used in cable-backed bows . Synthetic materials are now usually used for similar purposes, especially plastic and fibre glass . It is not to be confused with whale's bone meaning the bones of whales, used in carving, for cutlery handles and other uses for the bones of various large species.
AS A HABITAT
* John Henry Devereux South Carolina architect who used whale jaw bones to adorn the largest mansion on Sullivan\'s Island
* ^ Fudge, Douglas S.; Szewciw, Lawrence J.; Schwalb, Astrid N.
(2009). "Morphology and Development of Blue Whale Baleen: An Annotated
Translation of Tycho Tullberg\'s Classic 1883 Paper" (PDF). Aquatic
Mammals. 35 (2): 226–52. doi :10.1578/AM.35.2.2009.226 .
* ^ Szewciw, L. J.; De Kerckhove, D. G.; Grime, G. W.; Fudge, D. S.
* St. Aubin, D. J.; Stinson, R. H.; Geraci, J. R. (1984). "Aspects of the structure and composition of baleen, and some effects of exposure to petroleum hydrocarbons". Canadian Journal of Zoology. 62 (2): 193–8. doi :10.1139/z84-032 . * Meredith, Robert W.; Gatesy, John; Cheng, Joyce; Springer, Mark S. (2010). "Pseudogenization of the tooth gene enamelysin (MMP20) in the common ancestor of extant baleen whales" . Proceedings of the Royal Society B: Biological Sciences. 278 (1708): 993–1002. PMC 3049022 . PMID 20861053 . doi :10.1098/rspb.2010.1280 . Lay summary – Thoughtomics (March 16, 2011).