Graptemys species superficially resemble many other species of aquatic turtles, including sliders (Trachemys) and cooters (Pseudemys). However, they are distinguished by a keel that runs the length of the center of the carapace. In some southern species, the keel can result in vertebral spines, resulting in the map turtle’s other common name — “sawback”. They also typically grow to a smaller size at maturity. They are given the common name “map turtle” due to the map-like markings on the carapace. Map turtles are known for intricate head markings and strong sexual dimorphism with mature females twice the length and 10 times the mass of mature males.
Throughout the pet trade, Mississippi, common, and Ouachita map turtles were bred and hatched out by the thousands in the 1970s. Various other turtles were available, but as the salmonellosis Four-inch Law was established, map turtles and others slowly decreased in popularity. Today, these same three still hold the title for most common among the pet trade. Other species being captive-bred more often include the Texas map turtle, Cagle’s map turtle, and the black-knobbed map turtle. Some harder-to-find map turtles include the yellow-blotched map turtle and the Pearl River map turtle.