Homalopsis nigroventralis Deuve, 2006

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 : 149-150

Homalopsis nigroventralis Deuve , new combination

( Fig. 15 )

Material examined. – Ta Veng: FMNH 263029 , bamboo mixed with deciduous forest, O Lopeung Stream, 14 °10'39.2"N 107°17'25.1"E, 150 m elev., 19 Nov.2003 .

Siem Pang: FMNH 263030 , bamboo mixed with evergreen forest, O Kanome Stream, 14°13'33.7"N 106°36'16.0"E, 170 m elev., 30 Nov.2003 ; FMNH 263031-32 , bamboo mixed with evergreen forest, O Kanome Stream, 14°15'08.0"N 106°37'58.8"E, 175 m elev., 1 Dec.2003 ; FMNH 263033 , bamboo mixed with evergreen forest, 14°12'53.8"N 106°35'51.3"E, 100 m elev., 29 Nov.2003 .

Remarks. – A juvenile male, subadult male, two adult males, and an adult female agree with Deuve’s (1970) description of nigroventralis , as a subspecies of H. buccata (Linnaeus) from Laos, by having 11-13 supralabials; 15-16 infralabials; 35-38 longitudinal scale rows at midbody; 157-165 ventrals (mean ± SD 160.8 ± 3.2, N = 5); and a dark venter with light spots.

In life, the juvenile male (FMNH 263033) had light orange dorsal body bands; a broad tan band on the dorsal surface of head; a broken creamy-white ventrolateral stripe connecting the dorsal body bands; a distinctive white X-like marking on the chin; and a black venter with scattered white spots. The FMNH 259177 was killed on a road by a motor vehicle. FMNH 263014 was climbing at night (1925 hrs.) on the vertical trunk of a 10 cm DBH (diameter at breast height) sapling 4 m above the ground, 5 m from a 6 x 8 m stream pool at the base of a waterfall.

Saint Girons (1972a) reported the species from central and southwestern Cambodia.

Dinodon septentrionalis (Günther)

Material examined. – O’Rang: FMNH 263009 , hilly evergreen forest, O Kamen Stream, near 12°19'35.3"N 107°05'33.4"E, 500 m elev., 1 Nov.2003 .

three adults (FMNH 263030-32) had a brown dorsum with faint, lighter banding that disappeared posteriorly; an olive brown head with black markings on the snout and over eyes; venter yellowish-olive (FMNH 263030, male), olive (FMNH 263031, female), or olive-brown (FMNH 263032, male), darkening posteriorly to dark gray; creamy-white spots on the ventrals and subcaudals, beginning on the throat as a single spot on each ventral forming a longitudinal line, becoming more scattered posteriorly but sometimes arranged in pairs; creamy-white X-like marking on chin.

The juvenile was taken during the day (1400 hrs.) from the bottom of a 3 m wide swift stream flowing over solid rock substrate, 50 cm from the base of a 30 cm high cascade. The specimen was under 25 cm of water, with its head and anterior part of body emerging vertically from a small rock pile. The subadult was collected during the day (1255 hrs.) swimming under 25 cm of water in a shallow, 8 m wide flat stream with moderate current and a substrate of rocks. The adults drowned at night in gill nets set for catching fish in a 6 m wide stream with moderate current and substrate composed of sand and small rocks. The stream in which the juvenile was found in was mostly covered by forest canopy, but the other streams had no canopy cover, and were lined with tall grass, bamboo, and forest.

Homalopsis nigroventralis is easily distinguished from H. buccata by ventral colouration ( buccata has a white venter with black spots) and habitat preference ( buccata occurs in lentic and slow-moving bodies of water such as lakes, marshes and large rivers), and we treat them as separate species. Deuve (1970) reported that buccata and nigroventralis do not cooccur in Laos.

This is the first report of the species from Cambodia.

Figures

Fig. 15. Male and female Homalopsis nigroventralis (FMNH 263031-32) from Virachey National Park, Siem Pang District, Stung Treng Province, Cambodia.