2101 Dodson Ave

Del Rio Texas 78840
(830) 469-1045

Pseudemys Gorzugi –

The Rio Grande River Cooter

The Rio Grande River Cooter (Pseudemys gorzugi) is a freshwater river turtle native to the Trans-Pecos region of Texas. It is named after George Zug an eminent herpetologist. Herpetology is the study of reptiles and amphibians. P. gorzugi is a relatively large turtle with an oval shaped carapace (upper shell). They usually have bright yellow striping on their heads without the bright red spot found on the well-known Red-eared slider (Trachemys scripta elegans). Their carapace is attractively marked with whorls of various shapes and shades of green and yellow. Their plastron (underside) is pale yellow and sometimes salmon colored on the edges. Some individuals exhibit bright red striping on their forelimbs. Adults are vegetarians and will graze on aquatic plants, while juveniles will initially eat both animal and plant matter. Females are larger than males and can attain lengths up to 11.5 inches and weigh up to 7 pounds. Males will perform courting rituals to females and then mating will take place. Nests or clutches can contain 10-20 eggs and are usually deposited during the spring. Brightly colored hatchlings will emerge during late summer. This turtle can be found basking on either logs or rocks, although they tend to be shy and will retreat into the water if approached.

An isolated population located in Del Rio, TX can be easily observed in the clear waters of San Felipe Springs. Individuals may be seen from the HWY 90 bridge with only their heads out of the water or swimming through the vegetation. This specific population has an interesting history. During the mid-90’s poachers removed most of the adults, thereby diminishing the population. In 1998 a flood caused by torrential rains most likely washed away any remaining individuals. Since then this population has slowly rebounded by swimming back up river and adult turtles have once again been observed at the springs.

The most recent scientific study on this species is being conducted by M.R.J. Forstner, PhD, who works at the Biology Department at Texas State University-San Marcos. His work includes surveying populations and monitoring them genetically by using DNA technology. At the moment, P. gorzugi is considered Near Threatened by the International Union for Conservation of Nature and Natural Resources (IUCN). Local populations may be at risk from poaching, indiscriminate killing and diseases introduced by unwanted pet turtles that are released into their habitat. Local cooperation in preventing the release of pet turtles and poaching will undoubtedly help preserve this impressive turtle for future generations to appreciate.

David Rodriguez

B.S.,M.S.,PHD

Research Assistant Texas Tech University

Aka The Mexican Crocodile Hunter

• Gor•zu•gis - Pseudemys Gorzugi – referring to Rio Grande river turtle