Rhinoclemmys nasuta

(Boulenger, 1902)
Large-nosed wood turtle

This medium-sized (to 22 cm), dark, freshwater turtle has a strongly projecting snout. Its flattened adult carapace is medially keeled, only slightly serrated posteriorly, widest and highest just behind the middle, and black or reddish brown with black seams. The surface of the adult carapace is usually smooth, but that of juveniles is roughened with small rugosities. The plastron is well-developed, slightly upturned anteriorly, notched posteriorly, and yellow with a large reddish brown to black blotch on each scute. The plastral formula is: abd > pect > fem > an > gul > hum. The bridge is yellow with two dark blotches. The head is of moderate size with a projecting snout and a notched upper jaw. A cream to yellow stripe extends from the tip of the snout to each orbit, another stripe runs posteriorly from the orbit dorsolaterally to the nape, a third light stripe passes from the lower edge of the orbit to the tympanum, and another extends from the corner of the mouth to the tympanum. Dark vertical bars are present on the lower jaws. Skin of the neck and limbs is reddish brown to yellow. The feet are strongly webbed.
Females (to 22 cm) grow larger and wider than males (to 19.6 cm). Males have concave plastra and longer, thicker tails with the vent beyond the carapacial margin.

Rhinoclemmys nasuta occurs only in the Pacific drainages of western Colombia (the Quito, Truando, San Juan, Docampado, and Baudó rivers) and northwestern Ecuador, near Esmeraldas.

Geographic Variation
No subspecies have been named, but Ecuadorian Rhinoclemmys nasuta have wider carapaces and marginals (Ernst, 1978).

Rhinoclemmys nasuta lives in large rivers with strong current. It seldom climbs onto land except to nest or bask.

Natural History
What little we know of its biology is from Medem (1962). He reports they lay one, or possibly two, ellipsoidal (67-70 x 35-39 mm) eggs per clutch, usually in January to March, but some may lay throughout the year. Females construct poor, shallow, uncovered nests at best, and many merely lay their eggs among leaves on the ground.
Rhinoclemmys nasuta is principally herbivorous, but Medem reported one had eaten grasshoppers. This species does poorly in captivity.

IUCN Red List Status (1996)
Lower risk: near threatened.