Vanzolini, 1995
Brazilian slider
Recognition
The oval, rugose carapace has unserrated marginals, and a low medial keel on vertebrals 3-4. No size data were included with the original description, but a female paratype in the Smithsonian Institution (USNM 329467, originally MZUSP 3226) has a 14.4 cm carapace; plastron length is up to 14.7 cm (Paulo Vanzolini, pers. comm.). Vertebral 1 is broad and urn-shaped (constricted anteriorly); vertebrals 2-5 are broader than long, with the 5th flared posteriorly. Ground color is green to olive-brown with a pattern of large, black-bordered, reddish orange-centered, ocelli on each pleural scute. Each vertebral bears two narrow orangish, longitudinal stripes, and each upper marginal has a reddish orange bar. The hingeless plastron is yellow with an elaborate pattern of broad, olive-gray, dark-bordered lines, but no medial, longitudinal dark mark. Each bridge bears dark longitudinal bars, and a dark-bordered ocellus is present at the posterior edge of each lower marginal. The anal scute is slightly notched; the plastral formula is abd > an > gul > pect > fem > hum. The head is narrow with a slightly upturned, protruding snout and a medially notched upper jaw. The head is black on top, and yellow prefrontal arrow may be present. The broad yellow postorbital stripe contacts the orbit via a narrow isthmus. The chin and throat bear an inverted Y-shaped, yellow mark.
Males have long, thick tails with the vent beyond the posterior carapace rim.
Distribution
This turtle is known only from Santa Amaro, Maranhão, Brazil.
Geographic variation
None.
Habitat
Trachemys adiutrix lives in sand-bottomed permanent ponds in the dune-fields of Maranhão, Brazil. It wanders on land during the rainy season, but buries in the sand and aestivates during the dry season.
Natural History
Females usually lay clutches of 11-12 hard-shelled eggs, but one gravid female contained 24 eggs indicating two clutches per season.
Remark
T. adiutrix is very similar to and may prove to be a subspecies of T. dorbignyi.
IUCN Red List Status (1996)
Endangered (B1+2c).