Habitat and Ecology
Restricted to the mainstream of the Pecos and Rio Grande, and the lowermost few miles of tributaries (Ward 1984). Occurs as high as 1,082 m altitude in New Mexico (Degenhardt and Christiansen, in Ernst et al. 1994). Apparently absent from the Texas side of the lower Rio Grande (Ward 1984).
Examined gut contents were entirely vegetarian (Legler, in Ernst and Lovich 2009), although the species has also been thought to be omnivorous (Degenhardt et al. 1996, Ernst and Lovich 2009).
Animals reach up to 37.2 cm carapace length (CL) (Ernst and Lovich 2009). Limited information is available on reproduction: a clutch size of nine eggs has been reported; whether females produce multiple clutches remains unknown. Age and size at maturity remain unrecorded.