Eastern River Cooter

Pseudemys concinna concinna


Image of an eastern river cooter (turtle)
MDC Staff

Emydidae (basking, marsh and box turtles) in the order Testudines (turtles)


A medium-sized aquatic turtle with a broad shell and numerous stripes on the head, which is blunt and proportionately small compared to the shell. The upper shell is olive brown, brown, or nearly black, with numerous concentric yellow lines or markings. The lower shell is either plain yellow or may have some faint gray-brown markings along the scute seams, especially in the forward section. The head and limbs are normally olive brown or black with many yellow lines.

Similar species: The Mississippi Lowlands of southeastern Missouri is a zone where the ranges of several subspecies of river cooter overlap and interbreed, causing much variation in physical characteristics there. The similar-looking red-eared slider is distinguished by the red head stripe behind each eye, and by the lower shell, which is boldly marked with a dark brown smudge in each scute.


Upper shell length: 9 to 13 inches.

Eastern River Cooter-20180329-202.JPG

Four turtles sunning on a log. They are stacked domino-style.
Four eastern river cooters on a log in Mingo Wildlife Refuge.
Habitat and conservation

This species is most abundant in Missouri’s rivers and sloughs but also has taken up residence in some of our state’s large reservoirs in the southern half of the state. During the spring and summer, cooters spend a considerable amount of time basking in the sun on logs. They quickly slide into the water at the slightest disturbance.


A wide variety of aquatic plants make up the bulk of this species’ food, but some aquatic insects, mussels, snails, and crayfish are occasionally eaten. Heaviest foraging occurs in early morning and late afternoon.

Eastern River Cooter Distribution Map
Distribution in Missouri

Throughout the southern half of the state.

Life cycle

Courtship and mating occur in the water, and egg-laying apparently takes place in late May through June. A female lays up to 20 eggs, and hatching normally takes place in late August or September.

Human connections

The word “cooter” has African roots, arriving in the American South in the 1830s from the Bambara or Malinke word “kuta” (turtle). In Ozark dialect, “cooter” could mean nearly any hard-shelled turtle; it was also a verb meaning “wander aimlessly”: “He was a-cooterin’ round amongst the womenfolks.”

Ecosystem connections

Cooters graze on aquatic plants and are eaten by a variety of animals. Eggs and young turtles are most vulnerable to predators such as raccoons, herons, and large fish. Turtles and tortoises represent the oldest living group of reptiles on earth and are little-changed since the Triassic Period.