Turtles
I have covered 8 species of turtle for the area, however we have personally confirmed only 3 species as occurring within the confines of the Nueces Canyon. Two other species have been documented from the canyon, although one of these (Texas Slider) may have been extirpated from the area.
Turtles are unique among vertebrates in possessing a shell composed largely of bones - their spinal column, ribs, and sternum are all incorporated into their shell. Most turtles can withdraw to one degree or another into their shells for protection - this protection is most well developed in terrestrial turtles, less so in water turtles. The least well protected turtles (the softshell turtles) have their shells greatly reduced, and instead rely on camouflage to avoid predation.
The following 8 species may occur in or near the Nueces Canyon. An asterisk (*) denotes a species which we have personally confirmed as occurring here:
Common Snapping Turtle, Chelydra serpentina
Yellow Mud Turtle, Kinosternon flavescens
*Common Musk Turtle (Stinkpot), Sternotherus odoratus
*Red-eared Slider, Trachemys scripta
Texas Slider, Pseudemys texana (possibly extirpated)
Ornate Box Turtle, Terrepene ornata (possibly extirpated)
Texas Tortoise, Gopherus berlandieri (marginal)