A revision of Lycodon ruhstrati (Fischer 1886) auctorum (squamata colubridae), with the description of a new species from thailand and a new subspecies from the Asian mainland

The Asian colubrid species related to Lycodon ruhstrati (Fischer 1886) are revised on the basis of their morphology, pattern and colouration, in combination with DNA analyses. Lycodon ruhstrati auctorum is revealed to be a species complex. We restrict this specific nomen to populations of Taiwan. The mainland populations thus far gathered under this name form two taxa. For the first one, with dorsal scales entirely smooth, the name Lycodon futsingensis (Pope 1928) is available. The second taxon is described here as Lycodon ruhstrati abditus n. subsp. This subspecies is genetically close to the nominate form restricted here to Taiwan but differs by some morphological characters. In addition to the differences in ventral and subcaudal scale counts, and maxillary teeth formula, Lycodon ruhstrati abditus n. subsp. has keeled vertebral scales whereas in L. futsingensis all dorsal scales are unkeeled. Another new taxon is described here as Lycodon ophiophagus n. sp. to accommodate an isolated population on the Thai Peninsula. It is distinguishable by its ventral and subcaudal scale counts, the long posterior maxillary teeth, the colouration and by having keeled dorsal scale rows. Lycodon pauci-fasciatus is a valid species, redefined on the basis of new material from central Vietnam. Lycodon multifasciatus, until recently regarded as a subspecies of Lycodon ruhstrati, is also considered to be a valid species.