About Trimeresurus sumatranus (Raffles, 1822)
Trimeresurus sumatranus is a large, heavy-bodied pitviper with a prehensile tail. Adult individuals can reach a snout–vent length (SVL) of 1.6 metres (5 feet 3 inches), and their fangs grow to over 10 mm (3⁄8 in) long. This is an arboreal species that is pale green overall, with a red tail. The dorsal scales have black edges, and this black edging can form crossbands on more mature specimens. A white or yellow stripe runs along each side of the body, following the first row of dorsal scales. The ventral side of the body is greenish or yellowish, and the ventral scales may have thin black edges. Scalation characteristics include 21 (occasionally 23) rows of dorsal scales at midbody, 183–190 ventral scales in males and 182–191 ventral scales in females, 57–66 subcaudal scales in males and 55–64 subcaudal scales in females, and 8–10 supralabial scales. In Borneo, this species inhabits lowland forests at elevations below 800 meters (2,600 feet). Its confirmed geographic range includes southern Thailand, West and East Malaysia (Sabah and Sarawak on Borneo), and Indonesia (Bangka, Billiton, Borneo, Sumatra, and the nearby islands of Simalur and Nias). Its presence on the Mentawai Islands (specifically Sipora) is considered uncertain. The species' type locality is given as "Sumatra." According to Gumprecht et al. (2004), previous records of this species from the Mentawai Islands most likely refer to T. hageni instead.
