Nilssonia formosa

(Gray, 1869a)
Burmese peacock softshell turtle

The rounded carapace (to 65 cm) is olive gray to olive brown with blackish reticulations and four dark-centered, light-bordered ocelli in juveniles, which fade with age until the carapace becomes totally olive in large adults. There are several longitudinal rows of tubercles on the juvenile carapace that also disappear with age, but the series of enlarged blunt tubercles above the neck remains on the adult carapace. No preneural bone is present, and only a single neural bone occurs between the 1st of the eight pairs of costals. The 8th pair of costals is well-developed and meets at the midline. Surfaces of all the carapacial bones are pitted. The plastron is white and has four callosities (hyo-hypoplastral and xiphiplastral), and all the bones may be seen through the skin. Anterior extensions of the epiplastra are long, slender, and separated. The entoplastron lies at obtuse angles to the midline or is straight. The skull is of moderate size, and the bony snout is as long as or slightly shorter than the diameter of the orbit. There is a longitudinal ridge on the mandibular triturating surface at the symphysis; none occurs in the maxilla. Diameter of the mandibular symphysis equals or exceeds the diameter of the orbit. Head, neck, and limbs are olive with numerous yellowish dark-bordered spots; an elongated spot occurs on each side, near the back of the head, and other light spots occur on the temple, at the corner of the mouth, and on the chin. Undersides of chin and neck are cream colored. In adults the head is yellow with black markings.
Males have long, thick tails with the vent situated near the tip.

Nilssonia formosa is apparently restricted to the Irrawaddy, Sittang, and Salween rivers of Myanmar. Smith (1931) reported it was not uncommon in the lower Irrawaddy, and Annandale (1912) thought it ranged to near the border with China.

Natural History
Annandale (1912) reported a colony of N. formosa maintained in a tank at the Maha Myat Muni Temple in Mandalay. The tame turtles would come when called to be fed chicken and rice. Although Annandale found many individuals deformed, Peter Paul van Dijk (pers. comm.) did not see any deformed individuals when he visited the temple in 1992.

IUCN Red List Status (1996)
Vulnerable (A1acd+2cd, B1+2c).