The Big Bend slider (Trachemys gaigeae ), also called the Mexican Plateau slider, is a species of aquatic turtle in the family Emydidae. The species is endemic to the Southwestern United States and northern Mexico.
The epithet, gaigeae, is in honor of American herpetologist Helen Beulah Thompson Gaige, who collected the first specimen in the Big Bend region of Texas in 1928.
Adults of T. gaigeae have a straight carapace length of 5 to 11 inches (13 to 28 cm).
T. gaigeae is native to the United States in the states of New Mexico and Texas, and to northern Mexico in the state of Chihuahua. It is found primarily in the Rio Grande and Rio Concho.
Primarily aquatic, the Big Bend slider is often seen basking on rocks or logs in the water, and when approached quickly dives to the bottom. The only time it spends a large amount of time on land is when females emerge to lay eggs. It is an omnivorous species, with younger animals being more carnivorous, and progressively becoming more herbivorous as they age, with older adults being nearly entirely herbivorous.