Comparison of cranial form and function in association with diet in natricine snakes
Article first published online: 20 JUL 2011
Copyright © 2011 Wiley-Liss, Inc.
Journal of Morphology
Volume 272, Issue 12, pages 1435–1443, December 2011
How to Cite
Hampton, P. M. (2011), Comparison of cranial form and function in association with diet in natricine snakes. J. Morphol., 272: 1435–1443. doi: 10.1002/jmor.10995
- Issue published online: 10 NOV 2011
- Article first published online: 20 JUL 2011
- Manuscript Accepted: 24 APR 2011
- Manuscript Revised: 20 APR 2011
- Manuscript Received: 18 JAN 2011
- jaw mechanics;
The skull of squamates has many functions, with food acquisition and ingestion being paramount. Snakes vary interspecifically in the frequency, size, and types of prey that are consumed. Natural selection should favor phenotypes that minimize the costs of energy acquisition; therefore, trophic morphology should reflect a snake's primary prey type to enhance some aspect of feeding performance. I measured 19 cranial variables for six natricine species that vary in the frequency with which they consume frogs and fish. Both conventional and phylogenetically corrected analyses indicated that fish-eating snakes have relatively longer upper and lower jaw elements than frog-eating snakes, which tended to have broader skull components. I also compared the ratio of the in-lever to the out-lever lengths of the jaw-closing mechanism [jaw mechanical advantage (MA)] among species. Fish-eating snakes had significantly lower MAs in the jaws than did the frog-eating snakes. This result suggests that piscivores have faster closing jaws and that the jaws of frog-eating snakes have higher closing forces. Cranial morphology and the functional demands of prey capture and ingestion appear to be associated with primary prey type in natricine snakes. J. Morphol., 2011. © 2011 Wiley-Liss, Inc.