QUICK SEARCH:   [advanced] Author: Keyword(s):
Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents

This Article Full Text (PDF) References Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Moon, B. R. Articles by Gans, C. Search for Related Content PubMed PubMed Citation Articles by Moon, B. R. Articles by Gans, C.

Journal of Experimental Biology, Vol 201, Issue 19 2669-2684, Copyright © 1998 by Company of Biologists

JOURNAL ARTICLES

Kinematics, muscular activity and propulsion in gopher snakes

BR Moon and C Gans
Department of Biology, The University of Michigan, Ann Arbor, MI 48109, USA and Department of Zoology, The University of Texas, Austin, TX 78746, USA. bradmoon@umich.edu.

Previous studies have addressed the physical principles and muscular activity patterns underlying terrestrial lateral undulation in snakes, but not the mechanism by which muscular activity produces curvature and propulsion. In this study, we used synchronized electromyography and videography to examine the muscular basis and propulsive mechanism of terrestrial lateral undulation in gopher snakes Pituophis melanoleucus affinis. Specifically, we used patch electrodes to record from the semispinalis, longissimus dorsi and iliocostalis muscles in snakes pushing against one or more pegs. Axial bends propagate posteriorly along the body and contact the pegs at or immediately posterior to an inflection of curvature, which then reverses anterior to the peg. The vertebral column bends broadly around a peg, whereas the body wall bends sharply and asymmetrically around the anterior surface of the peg. The epaxial muscles are always active contralateral to the point of contact with a peg; they are activated slightly before or at the point of maximal convexity and deactivated variably between the inflection point and the point of maximal concavity. This pattern is consistent with muscular shortening and the production of axial bends, although variability in the pattern indicates that other muscles may affect the mechanics of the epaxial muscles. The kinematic and motor patterns in snakes crawling against experimentally increased drag indicated that forces are produced largely by muscles that are active in the axial bend around each peg, rather than by distant muscles from which the forces might be transmitted by connective tissues. At each point of force exertion, the propulsive mechanism of terrestrial lateral undulation may be modeled as a type of cam-follower, in which continuous bending of the trunk around the peg produces translation of the snake.

This article has been cited by other articles:

				Z. V. Guo and L. Mahadevan Limbless undulatory propulsion on land PNAS, March 4, 2008; 105(9): 3179 - 3184. [Abstract] [Full Text] [PDF]

				REVISION OF THE AISTOPOD GENUS PHLEGETHONTIA (TETRAPODA: LEPOSPONDYLI) Journal of Paleontology, November 1, 2002; 76(6): 1029 - 1046.

				B. Moon The mechanics of swallowing and the muscular control of diverse behaviours in gopher snakes J. Exp. Biol., January 9, 2000; 203(17): 2589 - 2601. [Abstract] [PDF]

				G. Gillis Patterns of white muscle activity during terrestrial locomotion in the American eel (Anguilla rostrata) J. Exp. Biol., January 2, 2000; 203(3): 471 - 480. [Abstract] [PDF]