Pascagoula Map Turtle

Graptemys gibbonsi (State Status: S2; imperiled)

Description

The Pascagoula Map Turtle, or Gibbon’s Map Turtle, is a brightly-colored map turtle found exclusively in drainages directly related to the Pascagoula River. Shells are more ovular and streamlined than G. flavimaculata, with pronounced ridge of dorsal spines. Shell color is brown or olive with light yellow rings on the front pleurals. The species is identified with its large colored blotch between the eyes (often bluish, green, or yellow in hue). These map turtles exhibit extreme sexual dimorphism, with females being up to and over 10 times as large as some males. Females will also sport megacephalic head development to aid in crushing shelled organisms such as mollusks. Map turtles often bask on branches, logs, and other vegetative matter, often angled at 45°. Despite the IUCN endangered status, this turtle may be locally abundant and is not yet listed under the US Endangered Species Act as G. flavimaculata and G. oculifera are.

Adult male, Stone Co. (MS)

Identifying Traits

  • Large colored blotch between eyes (separates from yellow-blotched)
  • Found only in Pascagoula River system (separates from Pearl River map turtle)
Range

Habitat

Rivers, tributaries, and oxbow lakes related to the Pascagoula River system

Behavior

Map turtles often bask on branches, logs, and other vegetative matter, often angled at 45°. 

Diet

Females use their large jaws on freshwater invertebrates such as snails and mussels, males forage on invertebrates and small mollusks

Megacephalic adult female, Wayne Co. (MS)
Adult female, George Co. (MS)
Dorsal view of a basking male, George Co. (MS)