Effects of asymmetry on the strength of the chelonian shell: A comparison of three species
Article first published online: 30 APR 2013
Copyright © 2013 Wiley Periodicals, Inc.
Journal of Morphology
Volume 274, Issue 8, pages 901–908, August 2013
How to Cite
Rivera, G. and Stayton, C. T. (2013), Effects of asymmetry on the strength of the chelonian shell: A comparison of three species. J. Morphol., 274: 901–908. doi: 10.1002/jmor.20146
- Issue published online: 13 JUL 2013
- Article first published online: 30 APR 2013
- Manuscript Accepted: 3 FEB 2013
- Manuscript Revised: 22 JAN 2013
- Manuscript Received: 20 NOV 2012
- NSF Postdoctoral Fellowship (G.R.) . Grant Number: DBI-0905898
- finite element;
- shell morphology;
A major focus of the field of organismal biology is to understand how morphology impacts performance. Although the functional implications of certain aspects of shape have been widely examined, the functional implications of a related parameter, symmetry, remain mostly unknown. We used finite-element models to examine the effects of turtle shell asymmetry on shell strength across three morphologically distinct emydid species. The goals of this study were to: 1) test the hypothesis that increased asymmetry (independent of differences in shape) is associated with increased stress levels for a given load, and thus with weaker shells, 2) ascertain how asymmetry and the position of load application interact to influence shell strength, and 3) determine how interspecific differences in shape influence the effect of asymmetry. We found that increased asymmetry does produce higher stresses for both midline and non-midline loads. Non-midline loads produce slightly larger and more variable stresses. Species-specific shell shape can mitigate the effects of asymmetry; stronger shapes are potentially more resistant to the negative effects of asymmetry. Our findings indicate that changes in asymmetry associated with relatively small changes in shape can have as much of an effect on stress incurred by the shell as the changes in shape themselves. J. Morphol. 274:901–908, 2013. © 2013 Wiley Periodicals, Inc.