Dixonius vietnamensis Das, 2004

Stuart Ko Sok Thy Neang, Bryan L., 2006, A Collection Of Amphibians And Reptiles From Hilly Eastern Cambodia, Raffles Bulletin of Zoology 54 (1), pp. 129-155 : 144

Dixonius vietnamensis Das

Material examined. – Pichrada : FMNH 261844-45 , rocky outcrop at base of Phnom Nam Lyr Mountain, near 12°32'16"N 107°32'10"E, 700 m elev., 18 Jun.2000 .

Keo Seima: FMNH 263008 , Keo Seima camp, 12°08'16.0"N 106°54'54.8"E, 160 m elev., 10 Nov.2003 ; FMNH 263003-07 , hilly evergreen forest mixed with deciduous and bamboo, near 12°10'34.9"N 106°57'47.6"E, 190 m elev., 9 Nov.2003 .

Siem Pang: FMNH 263002 , evergreen forest mixed with bamboo, waterfall of O Chhay Stream, tributary of O Chay Stream, 14°15'49.6"N 106°31'46.0"E, 200 m elev., 5 Dec.2003 .

Remarks. – These specimens agree with Das’ (2004) original description by having the adult head width (measured at angle of jaws) greater than head length (measured from posterior edge of posterior supralabial to snout tip); two supranasals in narrow contact; dark canthal stripe terminating at back of head; ear opening less than one half eye diameter; and adult SVL 42.1-46.3 (mean ± SD 45.2 ± 1.7, N = 5). The Cambodian specimens differ from the original description by having dark blotches on the lips in adults, and having two distinct colour morphs represented by both sexes: uniform grayish-brown (FMNH 263002-03, 263005-07) and grayish-brown with irregular black blotches on the dorsum (FMNH 263004, 263008). Only the second, blotched morph was described in the type series of two adult males and two juveniles. Smith (1935) noted the same two colour morphs in the similar D. siamensis (Boulenger) and stated that intergradation between them is rare.

Four adult males are present in the Cambodian series, and of these one ( FMNH 263007 , SVL 42.6 , uniform morph) has six preanal pores, two ( FMNH 263004 , SVL 46.0, and FMNH 261844 , SVL 46.5 , blotched morphs) have eight preanal pores, and one ( FMNH 261845 , SVL 46.1 , blotched morph) has nine preanal pores .

The specimens were active at night on a rocky outcrop and riverbank near the edge of forest, and within 75 cm of the ground on large tree trunks (40-150 cm diameter at breast height) in the forest. One (FMNH 263008) was found during the day retreating under a board next to a wooden building.

This is the first report of the species since its original description from Tinh Khanh Hoa Province, Vietnam.