IDENTIFICATION: This is the largest of our basking turtles. Adult females can reach 12-16.5 inches in carapace length while males can grow to 8-12 inches. The carapace is long, oval and widest at the midsection. The posterior marginal scutes are often serrated. The creamy yellow plastron is almost as long and wide as the carapace the bridge is wide and a notch is present on the posterior portion. The carapace is olive to brown with yellow lines creating a reticulating pattern. Dark spots surrounded by whorls are also present on the edge of the marginals and are divided by the suture line separating each marginal scute.
The head is dark green with thin yellow lines extending from the tip of the nose along the top of the haed. The coloration of the lines can vary depending upon the age of the specimen from bright to creamy yellow. Two large stripes are present on top of the head and a yellow spot is present just behind the eye. The limbs are also dark green and bear yellow lines extending down the front of them. A row of serrated scales is also present along the outer edge of the forelimbs. A suffusion of orangish-pink is often visible on the outer edges of the limbs and amid the webbing betwen the toes.
As specimens mature the briliance of the yellow lines begins to fade and a orange to pinkish coloration begins to replace the brown coloration of the plastron. This color is found under the edges of the marginal scales as well. Fleshy areas such as the thighs will also display this coloration. This age related shift in color is different from the sliders. whereas the former tend to become melanistic, our river cooters tend to turn pinkish orange.
A mature male specimen from Wise County, Texas. Notice the pinkish-orange coloration of the shell
BEHAVIOR AND ECOLOGY: Texas river cooters inhabit still or slow moving bodies of water such as slow moving portions of rivers, oxbows, ponds and lakes with soft bottoms abundant aquatic vegetation. This species is a gregarious basker and can be found soaking up sunshine alongside other basking turtles. Hatchlings and juveniles will consume various prey items including snails, insects, worms, crustaceans, small amphibians and small fish. As they grow their diet shifts towards aquatic vegetation including both algae and vascular plants.
