Lycodon

Ziegler, Thomas, Hendrix, Ralf, Thanh, Vu Ngoc, Vogt, Martina, Forster, Bernhard & Kien, Dang Ngoc, 2007, The diversity of a snake community in a karst forest ecosystem in the central Truong Son, Vietnam, with an identification key, Zootaxa 1493, pp. 1-40 : 13-14

Lycodon sp.

Another female Lycodon was collected by us about one month after the discovery of the afore mentioned Lycodon cf. ruhstrati . The discovery took place in the same region at an altitude of about 480 m above sea level. This second Lycodon ( Figure 13 ) was found at night of 30 July 2006, at the end of the dry season, crawling on pebbles near a steep primary forest stream cascade in the U Bo region. The specimen (ZFMK 86453, SVL 505, TaL 147, TL 652 mm) differs from the syntopic Lycodon cf. ruhstrati among others in having smooth dorsal scale rows, bearing enlarged vertebral scales, and having somewhat lower ventral and subcaudal counts (although within the range of L. ruhstrati , see above), as well as a differing banded pattern. The remaining scalation features of the specimen are as follows: eight supralabials, of which third to fifth are in contact with eye; 10 infralabials; one loreal, not in contact with eye; one preocular, not in contact with frontal; prefrontal not entering eye; two postoculars; two anterior temporals, followed by three posterior temporals; 17 dorsal scale rows at midbody; one undivided preventral and 208 ventrals; ventrals distinctly angulate laterally; anal entire; 85 divided subcaudals. Concerning coloration and pattern, the specimen has 20 dark transversal crossbands on its body dorsum, which continue on the venter (except for the neck band). The 19 creamy interspaces of the dark body crossbands are marbled by greyish-brown. Tail dorsum with 10 such light crossbands and 9 dark crossbars (including tail tip), underside of tail dark. On the right maxillary bone seven anterior fang-like teeth increasing in size were discernible, separated by a large toothless interspace from four medium-sized teeth, which were followed by three posterior teeth, the first two ones of which being distinctly enlarged.

This Lycodon specimen morphologically resembles the female L. ruhstrati specimen from Ha Tinh province as shown in Ziegler (2002). However, the latter specimen has no enlarged vertebrals and bears minor differences in the banded pattern. The Ha Tinh specimen further shows a distinct light area on the rear head, however, that is still slightly discernible in the larger Lycodon specimen from Phong Nha - Ke Bang as obscured area. As was pointed out above, only future research including currently undertaken molecular methods will prove, whether the mainland " L. ruhstrati " with smooth dorsal scales in fact represent a separate taxon (cf. L. futsingensis ) and whether mainland L. cf. ruhstrati (with keeled dorsal scales) represent an unnamed taxon indeed, different from the populations from the terra typica in southern Taiwan.

Figures

FIGURE 13. Dorsal view of Lycodon sp. from Phong Nha - Ke Bang (ZFMK 86453). Photo: Ralf Hendrix