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[[tr:Gölgeli yunus]]
[[Image:Baleen.jpg|frame|Baleen hair is attached to each baleen plate|alt=Photo displaying dozens of baleen plates. The plates face each other, and are evenly spaced at approximately {{Convert|0.25|in|cm|0}} intervals. The plates are attached to the jaw at the top, and have hairs at the bottom end.]]
'''Baleen''' or '''whalebone''' is a built in filter-feeder inside of some of the whales. The whale would open its mouth underwater and water would then pour into the whale's mouth. They would then push the water out, but the animals such as '''krill''' would end up as a meal for the whale. Baleen is like bristles, but are the same substance found in fingernails,hair, and the sand-paper like feeling on a cat's tongue. Some whales have longer baleen than others, like the '''bowhead whale'''. Others only use one side of their baleen, like the '''gray whale''' These baleen bristles are arranged in plates across the upper jaw of the whale.
Depending on the species, a baleen plate can be {{convert|0.5|to|3.5|m|ft}} long, and weigh up to {{Convert|90|kg|lb|sigfig=1}}. Its hairy fringes are called baleen hair or whalebone-hair. They are also called baleen bristles, which in [[sei whale]]s are highly calcified, calcification functioning to increase their stiffness (Fudge ''et al''. 2009; Szewciw ''et al''. 2010). Baleen plates are broader at the gumline (base). The plates have been compared to [[sieve]]s or [[Window blind#Venetian|Venetian blind]]s.
==Evolution==
The oldest true [[fossil]]s of baleen are only 15 million years old, but baleen rarely fossilizes, and scientists{{Who|date=January 2010}} 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. Baleen is believed to have evolved around thirty million years ago, possibly from a hard, gummy upper jaw, like the one a [[Dall's porpoise]] has. In fact, it resembles baleen closely at the microscopic level.
Curiously, many early baleen whales also had teeth, but 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).
==Filter feeding==
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 [[Shoaling and schooling|shoal]]s of prey (such as [[krill]], [[copepod]]s, small [[fish]] and sometimes [[bird]]s 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.
==Human uses==
Whalebone was formerly used for making numerous items where flexibility and strength were required, including [[collar stiffeners]], [[buggy whip]]s and [[parasol]] ribs, and as [[corset]] [[Bone (corsetry)|stays]]. It was commonly used to crease [[paper]]; its flexibility kept it from damaging the paper. It was also occasionally used in [[cable-backed bow]]s. Synthetic materials are now usually used for similar purposes, especially [[plastic]] and [[Glass reinforced plastic|fibre glass]]. Baleen plates are also used by indigenous people to create fine crafts.
==As a habitat==
Whalebone serves as a habitat for some species from the gastropod families [[Pyropeltidae]], [[Cocculinidae]], [[Osteopeltidae]] and [[Neolepetopsidae]].<ref name="McLean2008">McLean J. H. 2008. [http://findarticles.com/p/articles/mi_m0QPU/is_1_27/ai_n25378214/ ''Three New Species of the Family Neolepetopsidae (Patellogastropoda) from Hydrothermal Vents and Whale Falls in the Northeastern Pacific'']. Journal of Shellfish Research 27(1):15-20. 2008, doi: 10.2983/0730-8000(2008)27[15:TNSOTF]2.0.CO;2 ([http://www.bioone.org/doi/abs/10.2983/0730-8000(2008)27%5B15:TNSOTF%5D2.0.CO%3B2 abstract])</ref>
==See also==
* [[Baleen whale]]
== References ==
{{reflist}}
*Fudge, D.S., Szewciw, L.J., and A.N. Schwalb. 2009. Morphology and development of blue whale baleen: An annotated translation of Tycho Tullberg's classic 1883 paper. ''Aquatic Mammals'' '''35'''(2):226-252.
* Szewciw, L.J., de Kerckhove, D.G., Grime, G.W., and D.S. Fudge. 2010. Calcification provides mechanical reinforcement to whale baleen alpha-keratinceedings of the Royal Society B'' '''277''':2597-2605.
==Further reading==
* St. Aubin, D.J, R.H. Stinson and J.R. Geraci 1984. "Aspects of the structure and function of baleen, and some effects of exposure to petroleum hydrocarbons". ''Canadian Journal of Zoology'' 62: 193-198
{{Whaling}}
[[Category:Cetaceans]]
[[Category:Whale products]]
[[zh-min-nan:Keng-chhiu]]
[[bg:Балена]]
[[ca:Barba (balena)]]
[[de:Barte (Wal)]]
[[en:baleen]]
[[es:Barbas de ballena]]
[[eo:Balenlameno]]
[[fr:Fanon (cétacés)]]
[[hr:Usi]]
[[io:Barto]]
[[ik:Suqqaq]]
[[is:Skíði (hvalir)]]
[[it:Fanone]]
[[ka:ვეშაპის ულვაში]]
[[hu:Szila]]
[[nl:Balein]]
[[ja:鯨ひげ]]
[[no:Hvalbarde]]
[[pl:Fiszbiny]]
[[pt:Barbas de baleia]]
[[ru:Китовый ус]]
[[sh:Usi]]
[[fi:Hetula (valas)]]
[[sv:Barder]]
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