Meeting Abstract

P1.139  Friday, Jan. 4  Exploring the phenotypic plasticity of intestinal responses for snakes MENZEL, E.J.*; SECOR, S.M.; University of Alabama; University of Alabama ejmenzel@crimson.ua.edu

The proposed dichotomy in the capacity for phenotypic flexibility of snake intestine is seated in studies on distinctly frequent or infrequent feeding species. However, snake feeding habits lie along a continuum and species do exhibit distinct ontogenetic shifts in feeding habits and/or possess populations that differ in feeding ecology. Snake species that posses large geographic ranges and therefore have populations that vary in feeding habits due to localized diversity and abundance of suitable prey, may exhibit a single established intestinal response or a mosaic of responses that reflect localized feeding habits. This study explores whether population differences in feeding habits are matched in a predicted fashion to their corresponding intestinal response. The species chosen for this study was the cottonmouth, Agkistrodon piscivorus. From preserved specimens we analyzed for differences with respect to feeding state microvillus length. We used variation in microvillus length as a proxy of intestinal regulation. Very short microvilli (~0.5 μ m) and much longer microvilli (~ 2 μ m) would indicate that the species widely regulates intestinal performance. The lack of any significant differences in microvillus length (2±0.5 μ m) among museum specimens would suggest that the species modestly regulates intestinal performance. Specimens showed significant statistical difference in microvilli length between those with (1.4±0.02 μ m) and without food items (1.4±0.02 μ m) in the gut (p<0.01, F=103.76). Although there is a significant difference in microvillus length they are not of the magnitude of difference seen in infrequently feeding pythons and boas. This suggests that there is relatively modest regulation between fasted and fed snakes.