Lateral undulation
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182426113
2008-01-06T01:01:56Z
Mmcannis
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edit...(extra word)-...(adding category: [[Category:Fossil trackways]])-
'''Lateral undulation''' is the most primitive of [[vertebrate]] [[locomotor]] patterns, present even in [[hagfish]], [[lamprey]]s, and [[lancelet]]s. It is used both in the water and on land, most notably by [[snake]]s in the latter setting.
One can roughly describe lateral undulation as a sequence of alternating left-right '''body waves''' propagating posteriorly along the animal. This is accomplished by unilateral, posteriorly-propagating [[muscle]] activity, which means that, at any point on the animal, only muscles on the left or right side are active, and the active region of muscle contraction moves from head to tail.
In the water, this motion causes the posterior edge of each body-wave to push water backwards, which results in a net forward force on the animal. On land, the same effect is accomplished, but by pushing on soil, rocks, plants and other irregularities in the substrate.
==See also==
* [[Fish anatomy]]
* [[Terrestrial locomotion in animals]]
==External links==
* [http://icb.oxfordjournals.org/cgi/content/full/42/5/981 Riding the Waves: the Role of the Body Wave in Undulatory Fish Swimming]
[[Category:Zoology]]
[[Category:Animal anatomy]]
[[Category:Locomotion]]
[[Category:Fossil trackways|Undulation, Lateral]]
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