A new species of the genus Trimeresurus Lacépède, 1804 (Reptilia, Squamata, Viperidae) from Southwestern China

Trimeresurus nujiang sp. nov., a new cryptic species of green pit viper is described from southwestern China, based on specimens collected from Gongshan County, Nujiang Lisu Autonomous Prefecture, Yunnan Province, China. Phylogenetic analyses based on DNA sequences of the mitochondrial cyt b, ND 4,12S rRNA and 16 S rRNA genes supported the new species as an independent lineage (BPP 1.00 / BS 100), closely related to T. stejnegeri and T. yunnanensis.

A combination of characters helps delimit the new species from its congeners by: (1) ventrolateral stripe white (above) and dark red (below), present on the first row of dorsal scales in males; ventrolateral stripe faint white present in females; (2) postocular streak absent in both genders; (3) iris golden yellow in both genders; (4) DSR 19 (21 / 22) – 19–15 (13), VEN 164–173, SC 57–68; (5) first upper labial completely separated from the nasal; (6) hemipenes short and spinose, bilobed at 6 th / 7 th plate when unextruded, tips reaching SC 10.

The uncorrected genetic distances of mitochondrial gene cyt b between the new species and other congeners range from 0.052 (T. stejnegeri) to 0.156 (T. hageni).