Biology Pre-Vet Major
Physical and Biological Sciences Category
My name is Kylie Atkinson. I’m a senior pre-vet biology student. I have worked in Dr. Penning’s Reptile Physiology Lab for almost a year and have taken several classes with him. My interest in snake anatomy, additional research by fellow reptile laboratory students, a research grant aid, and Dr. Penning’s advice encouraged this study on Cottonmouth axial musculature.
As an animal grows, its body often changes in the distribution of its body mass. For example, as humans grow, their heads grow disproportionately slower than the rest of their bodies. Therefore, an adult human, while having a head that is absolutely larger than a child’s head, has a head that is relatively smaller compared to their overall body size. This change in shape and size across growth is what occurs in most animals across their ontogeny. Any change in growth across ontogeny can have major functional consequences to what any given animal can accomplish. For snakes, striking behavior is accomplished through the use of interconnected axial muscles. These muscles are likely to change in size as an animal grows. Larger muscles produce higher forces so it is possible that there is selection for relatively larger muscles as snakes grow. To investigate how the axial muscles change in snakes, I dissected 11 Cottonmouth Vipers (Agkistrodon piscivorus) of a wide size range (7.9-724 g) in order to quantify how their muscles change with increasing body size. Further, I measured the cross-sectional area of the major epaxial muscles at 5 locations along their body to test for potential differences in muscle composition along a snake’s axial system.