Exploring Eastern Musk Turtle (Sternotherus odoratus) Population Dynamics And Phenotypic Plasticity In Comal Springs, Texas

Abstract

Freshwater turtles are vital to aquatic ecosystems but are increasingly affected by anthropogenic change. The eastern musk turtle (Sternotherus odoratus) is a small, omnivorous species inhabiting spring systems in Central Texas, where invasive gastropods have become abundant. This study investigates whether dietary shifts toward these gastropods are associated with variations in head and body morphology. Seventy-one individuals were captured in June and July 2024. Morphometric data and fecal samples were collected to assess diet composition and morphological variations. Dietary analyses identified Tarebia granifera as the dominant prey item. Males exhibited stronger allometric relationships between head width and body size. Head width did not significantly differ between sexes. A comparison with museum specimens revealed significant increases in carapace length and head width. These findings suggest that invasive prey may be driving morphological changes through phenotypic plasticity and highlight the capacity for freshwater turtles to adapt to novel ecological pressures.