Meeting Abstract

P2.80  Sunday, Jan. 5 15:30  Morphological and mechanical changes in red-eared slider turtle (Trachemys scripta elegans) shells during growth FISH, JF*; STAYTON, CT; Bucknell University; Bucknell University jff008@bucknell.edu

Turtles experience numerous changes as they develop, specifically modifications in their morphological, physiological, and mechanical characteristics. Growth changes in turtles are associated with different abilities to defend against predators. Specific aspects of changes in the turtle shell’s size, shape, strength, and rigidity have not been quantitatively studied prior to our research. This study investigates the morphological and mechanical changes that juvenile Trachemys scripta elegans undergo as they increase in size. Turtles undergo notable changes in shell morphology and ossification as they grow, but these changes are rarely quantified and have never been related to the mechanical behavior of the shells. Morphology and shell rigidity were quantified in a sample of 36 alcohol-preserved juvenile Trachemys scripta elegans. Morphometric information was then used to create finite element models of all specimens. These models were used to assess the mechanical behavior of the shells under various loading conditions. Overall, we find that turtles experience complementary changes in size, shape, and relative strength as they grow. As turtles age their shells become larger, more elongate, relatively flatter, and more rigid. In an absolute sense, their shells become stronger but relatively weaker in shape, compared with younger turtles. We suggest that the mechanical implications of shell size, shape, and deformability may have a large impact on survivorship and development in these turtle species as they mature.