Enhydris chanardi, Murphy & Voris, 2005

Murphy, John C. & Voris, Harold K., 2005, A New Thai Enhydris (Serpentes: Colubridae: Homalopsinae), Raffles Bulletin of Zoology 53 (1), pp. 143-147 : 144-146

Enhydris chanardi , new species

( Figs. 1A , 2)

Hypsirhina jagorii – Günther, 1864: 282; Nicholson, 1874: 62; Boulenger, 1896: 6; Flower, 1899: 676; Bourret, 1936: 278 (part) (not Hypsirhina jagorii Peters, 1863 ).

Enhydris jagoriii – Cochran, 1930: 31; Smith, 1943: 384 (part); Gyi, 1970: 92, Fig. 10; Campden-Main, 1970: 77; Cox, 1991: 190, Pl. 57 (colour photograph); Cox et al., 1998: 41 and unnumbered photograph (not Hypsirhina jagorii Peters, 1863 ).

Material Examined. – Holotype - USNM 67516 female, Bangkok (13 45’N 100 31’E), Thailand, coll. Hugh M. Smith, 1 May.1928.

Paratypes – BMNH Bangkok 98.11.830-1,1969.1884-1885, 1968.780-781; Chanthaburi, Thailand 1987.1786; Siam 59.7.1.9, 65.4.28.5, 78.2.14.14; Takhamen 97.10.8.28 . CAS 135735 , rice fields of Bangkok . LSUMZ 16922 , skin only, purchased in Bangkok market; UMMZ 65336 , near Bangkok ; USNM 83431 Ban Pan, Sikuk River , coll. Hugh M. Smith, 25 Nov.1923 .

Diagnosis. – Enhydris chanardi can be distinguished from all other Enhydris in the Indochinese Peninsula that have 21 scale rows at mid-body by the following characteristics: 116- 125 ventrals, 38-60 subcaudals (53-60 in males and 38-49 in females); two pairs of chin shields with the second pair longer in length; an interocular distance that is greater than the length of the frontal; scales that are longer than tall on rows 7-15; lateral spots on rows 4-5 or 4-6 ( Fig. 1 ); and a stripe on scale row three. See Fig. 1A and Table 1 for a comparison to other taxa.

Description of Holotype. – Head is depressed and distinct from neck; the body cylindrical at midpoint, strongly compressed immediately in front of vent; tail strongly

each ventral contain grey pigment which extends onto dorsal scale rows 1-2, and forms a stripe that runs the length of the body. Dorsal scale row three and the lower portion of scale row four have predominantly yellow pigment that forms a yellow stripe bordering the lower gray stripe. Yellow pigment occasionally intrudes into the more ventral gray stripe. Rows 5-7 contain black spots that involve 2-4 scales and are spaced 1-2 scale rows apart; spots number 47 on the right side and 45 on the left side. The dorsum is a grey-brown with a series of spots similar to those on rows 5-7; spots follow the vertebral line and number 37. The subcaudal scales have anterior dark pigment and posterior light pigment.

Variation. – The largest specimen measured was a female with a total length 544 mm and an 84 mm tail (15.4%). The smallest specimen, a male neonate, had a total length of 166 mm with a 39 mm tail (23.5%). A male from Chanthaburi, Thailand (BMNH 1987.1786) has the lowest ventral and subcaudal counts (110 and 44 respectively). All specimens examined had eight supralabials, the tallest of which could be number five (19%), six (50%), or seven (31%). The first 4-5 infralabials touch the anterior chin shields. The infralabials on 18 sides usually numbered 10 (67%), but some had 11 (22%), or 12 (11%). The largest infralabial was usually number six (80%), but occasionally number seven (20%). The temporal formula is usually 1+2+4, but two specimens show 1+2+3 on one side.

Etymology. – We are pleased to name this new species after our friend and colleague, Thai herpetologist, Mr. Tanya Chanard, who, like this newly recognized snake, is native to the Bangkok area.

Distribution. – Most of the specimens of this snake come from Bangkok or the surrounding area. Flower (1899) obtained three specimens in Bangkok and one (BMNH 97.10.8.28) at “Takhamen.” Presumably this location is Ta Kam (13 38’N 100 27’E) (also spelled Takam) just west of Bangkok. The locality for a specimen collected by H. M. Smith at Ban Pan on the Sikuk (or Sikut River) could not be found. BMNH 1987.1786 from Chanthaburi (12 36’N 10 29’E) in the Coastal Ranges to the southeast of Bangkok suggests the species is more widespread than the immediate Bangkok metropolitan area.

Natural History and Conservation. – Relatively little is known about the habitat, food habits, and reproduction of this species. Most known localities lie within freshwater environments of metropolitan Bangkok. The specimen USNM 83431 is a female with 14 well-developed embryos. We have not yet found an extant population, although the Chanthaburi specimen was collected in the past 20 years. Efforts should be undertaken to locate existing populations.

Figures

Fig. 1. A comparison of the lateral patterns on the body of Enhydris chanardi (A) UMMZ 65336 and Enhydris jagorii (B) ZMA 4746. The specimen of Enhydris jagorii (ZMA 4746) in the photograph is the type specimen. The small arrows indicate the ventral scale row in each photograph.