The male donut turtle has a narrow and long carapace, long front claws, thick tail root, and cloaca far from the plastron. Female turtles are the opposite. Males have more pronounced tails and may have slightly recessed plastrons, while females tend to be larger than males. Like other terrapins that like to bask their backs, donut turtles tend to have smaller males than females. Males exercise their straight, slender claws as part of the mating dance.

After sniffing the tail of the female turtle, it may be that some kind of After the message of the pheromone, the male turtle will swim to the female turtle, vibrate his long claws, tap her face, and woo her. It has been observed that female turtles also make such movements to initiate courtship. If the female accepts, she will sink to the bottom of the river, allowing the male to climb on top of her to mate. Mating takes place in early spring. Nesting and spawning are usually from May to June.