Summary

The Big Bend slider, Trachemys gaigeae (Family Emydidae), is a medium-sized freshwater turtle (carapace length to 308 mm) that is limited to riverine areas of the desert southwestern United States and northern Mexico. Two allopatric subspecies are currently recognized, T. g. gaigeae and T. g. hartwegi, which might represent distinct species. Degradation and fragmentation of riverine habitat is likely the most significant threat to T. gaigeae in both the United States and Mexico. Overcollecting for the pet trade or as food and hybridization with introduced Trachemys scripta are also of concern, although more information is needed. Commercial collection is prohibited in the United States but otherwise this slider receives little protection, except where it occurs on public lands. The species uses reservoirs and artificial ponds in New Mexico, suggesting some adaptability to human-modified environments. The status and ecology of this species in the United States has been little studied until recently and even less is known about populations in Mexico.