The Coahuilan box turtle (Terrapene coahuila) is a small aquatic species of box turtle which lives in Mexico, specifically in the Cuatro Ciénegas basin of central Coahuila. This species is the most aquatic turtle of the genus Terrapene.

This turtle species inhabits permanent and seasonal ponds and wetlands—a specific and sensitive habitat to which it is dependent. When not foraging, it selects to bury itself in the mud in or near the water bodies where it lives. Nevertheless, it is less aquatic than the sympatric species found in Cuatro Ciénegas; the Cuatro Cienegas Slider (Trachemys taylori) and the Cuatro Cienegas Softshell (Apalone spinifera atra). The high salinity of the water gives a white appearance to the Coahuilan box turtle’s shell when the water dries. The Coahuilan box turtle is mostly omnivorous, mainly feeding on plants and insects.

Unfortunately, this species faces many threats. The primary reason is habitat loss due to human hydrological activities—specifically those linked to the pumping of groundwater and increased diversion by canals. Agriculture and cattle ranching is also being developed in the area which requires a substantial amount of water. These combined activities have caused the shallow pond habitat of the Coahuilan box turtle to dry up significantly. Furthermore, the illegal collection and poaching of this turtle for the pet trade has occurred in the past, indicated by the presence of wild caught animals in private collections.

A studbook exists in Europe and in the United States for this species, monitoring births, deaths, parentage lines, individuals acquired from the wild, the location of individuals, and transfers of individuals. Trends in the studbook show that the Coahuilan box turtle is bred quite well in captivity.

The Turtle Conservancy has participated in surveys over the past few years and the threats to the Coahuilan Box Turtle were evident. The situation of this box turtle in the wild must be monitored extensively to ensure its survival. Fortunately, the Mexican government declared 84,347 hectares of the Cuatro Ciénegas as a protected area. However, this will not be enough and further conservation initiatives must be taken in the upcoming next few years to protect the habitat of the turtle.