Characteristics

Among the many freshwater turtle species, the visually distinctive Barbour's map turtle (Graptemys barbouri) stands out due to its unusual and unusually shaped shell. The extremely dome-shaped carapace decorated with elaborate, map-like patterns is one of the most striking characteristics of the Barbour's map turtle. The popular name for this species comes from the fact that its patterns resemble topographic lines seen on maps; they are composed of yellow or orange lines on a dark brown to olive basis.

In the case of Barbour's map turtles, sexual dimorphism is clearly visible, since the males are much smaller than the females. Male turtles are usually only around 14 centimeters (5.5 inches) in length, but females may reach 33 centimeters (13 inches) in length. Females are noticeably larger than males, and not just in terms of length but also in general robustness and girth.

Particularly noticeable in juveniles and females, the carapace of a Barbour's map turtle has a distinct keel running down its middle. Although these keels may fade with age, they are still easily identifiable. From above, the turtle seems jagged because its carapace has serrated edges on the back.

On the underside of a turtle's shell, called the plastron, you may find a lighter shade of color (anything from cream to yellow) with the occasional darker spot or pattern. In contrast to the dome-shaped carapace, the plastron has a somewhat flat form. Because the plastron hinges are fixed, turtles are unable to fully shut their shells.

There are additional distinguishing markings on Barbour's map turtle's head and limbs. Spots and stripes of brilliant yellow provide a dramatic contrast to the otherwise dark skin, which is often black or dark brown. From the snout down the neck and around the eyes, these patterns continue onto the skull in the form of yellow lines. They are able to blend in more seamlessly with the river's natural light and shadow patterns because to their distinctive striping.

The underwater existence of the Barbour's map turtle is reflected in its muscular, clawed limbs. Webbing between the toes on the front limbs makes swimming more effective. As a courtship and mating display, male aquatic turtles often show larger claws on their front foot than females. This trait is shared by many species of turtles.