THE RAFFLES BULLETIN OF ZOOLOGY 2005 THE RAFFLES BULLETIN OF ZOOLOGY 2005 53(1): 143-147 © National University of Singapore A NEW THAI ENHYDRIS (SERPENTES: COLUBRIDAE: HOMALOPSINAE) John C. Murphy and Harold K. Voris Division of Amphibians and Reptiles, Field Museum of Natural History, 1400 South Lake Shore Drive, Chicago, Illinois 60605, USA Email: hvoris@fieldmuseum.org (HKV) ABSTRACT. – A new species, previously misidentified in museum collections and the literature as E. jagorii, is described. All specimens of the new taxon with specific locality data are from the vicinity of metropolitan Bangkok. It can be distinguished from other Enhydris with 21-23 scale rows at mid-body by the presence of 21 scale rows on the neck, 110-122 ventrals, and a distinctive pattern of small dorsal spots. KEY WORDS. – Homalopsinae, water snakes, Enhydris, new taxon, Thailand. INTRODUCTION The Oriental-Australian rear-fanged water snakes in the colubrid snake subfamily Homalopsinae were reviewed by Gyi (1970) who recognized 10 genera and 34 species. The genus Enhydris was the most specious (22 species). Enhydris species usually use freshwater habitats with muddy substrates, feed on fish and anurans, can attain high population densities, and have a distribution that extends in a northwest-southeast axis from Pakistan’s Indus River to eastern Queensland, Australia. Two species (E. enhydris and E. plumbea) have broad geographical distributions, while others are restricted to particular islands, river basins and coastlines (Murphy & Voris, 1994; Murphy et al., 1999; Stuart et al., 2000; Voris & Murphy, 2002). During the examination of museum specimens and the literature it became clear that the identity of Hypsirhina jagorii Peters, 1863, was confused by Günther (1864) as well as all subsequent workers (Morice, 1875; Tirant, 1885; Boulenger, 1896; Flower, 1899; Mocquard, 1907; Cochran, 1930; Bourret, 1934, 1936; Smith, 1943; Deuve, 1970; Gyi, 1970; St. Girons, 1972a, b). Museum material labeled Enhydris jagorii was composed of two species. Neither of these species were conspecific with the type of Hypsirhina jagorii Peters, and this problem will be resolved in a separate paper. The confusion resulted from similar meristic characteristics. Five species of Enhydris that occur in Thailand and the Indochinese Peninsula and have 21 scale rows at mid-body are compared in Table 1. MATERIALS AND METHODS Museum material was compared to written descriptions and illustrations. A total of 144 specimens were examined (Appendix 1). Scales were counted following Peters (1964). Scale measurements were made using dial calipers to the nearest 0.1 mm. Body measurements were made to the nearest millimeter using a meter stick; snout-vent length (SVL) and total length (LOA) were collected. Bilateral scale counts are listed as left/right sides. Sex was determined by the presence or absence of hemipenes, tail shape, and probing. Scale arrangements and specimens were photographed using a Sony Cybershot DSC-S85 digital camera. Sarah Drasner illustrated the paratype in Fig. 2. Specimens examined are housed in the following institutions: American Museum of Natural History (AMNH), New York; British Museum of Natural History (BMNH), London; California Academy of Sciences (CAS), San Francisco; Field Museum of Natural History (FMNH), Chicago; Louisiana State Museum of Zoology (LSUMZ), Baton Rouge; Museum National d’Histoire Naturelle (MNHN), Paris; Muséum of Zoology (CUMZ), Bangkok; Museum of Zoology, University of Michigan (UMMZ), Ann Arbor; National Museum of Natural History (USNM), Washington; National Science Museum (THNHM), Bangkok; Queen Saovabha Memorial Institute, Thai Red Cross Society (QSMI), Bangkok; Zoologisches Museum, Universität Humboldt (ZMB), Berlin. RESULTS Enhydris jagorii can be distinguished from most other species of Enhydris with 21-23 scale rows at mid-body by its low ventral (117-127) and subcaudal (48-54 in females and 5368 in males) scale counts; the anterior pair of chin shields are longer than the second pair (or rarely the same length), 143 Murphy & Voris: A new species of Enhydris Table 1. A comparison of six species of Enhydris with 21 scale rows at mid-body. LOA indicates total length of body and tail. Characters n= LOA males (mm) LOA females (mm) Tail/LOA males Tail/LOA females Dorsal scale rows on neck Dorsal scales rows mid-body Dorsal scales rows post-body Dorsal scale ornamentation Ventrals - males Ventrals - females Subcaudals - males Subcaudals - females Number of pairs of chin shields Shape of anterior chin shields Longest pair of chin shields Labials touching loreal Temporal scales Pattern on scale rows 1-3 Pattern on scale rows 5-7 Pattern on edges of ventrals Mid-ventral pattern posterior Eye diameter to nasal diameter Distribution E. enhydris 60 E. chanardi 15 E. jagorii 10 E. innominata 18 E. longicauda 41 154-741 – (χ=505) 203-714 – (χ=565) 0.15-0.29 – (χ=0.22) 0.16-0.26 – (χ=0.21) 21-27 – (χ=23.8) 21-23 – (χ=21.2) 19-21 – (χ=20.3) striated 153-174 – (χ=160) 153-170 – (χ=157) 64-83 – (χ=71) 57-76 – (χ=65) 2 (3 rarely) elongate 2 first 3 plate-like stripe stripe or uniform 166-425 – (χ=281) 234-547 – (χ=461) 0.21-0.23 – (χ=0.22) 0.15-0.18 – (χ=0.17) 20-23 – (χ=21.1) 21 – (χ=21.0) 19-21 – (χ=20.4) smooth 110-121 – (χ=118) 116-122 – (χ=120) 44-60 – (χ=53) 38-49 – (χ=44) 2 flared 2 first 3 plate-like stripe spots 2-3 scales solid or serrated stripe stripe equal widespread zig-zag stripe 317-471 – (χ=412) 290-515 – (χ=387) 0.22-0.25 – (χ=0.24) 0.15-0.2 – (χ=0.19) 23-25 – (χ=24.0) 21-23 – (χ=21.4) 19-20 – (χ=19.7) smooth 117-127 – (χ=120) 117-120 – (χ=123) 53-68 – (χ=61) 50-54 – (χ=51) 2 flared 1 first 3 small blotched blotches, 4-5 scales uniform 233-470 – (χ=397) 215-650 – (χ=486) 0.19-0.25 – (χ=0.21) 0.15-0.19 – (χ=0.16) 23-25 – (χ=23.5) 21 – (χ=21.0) 19-21 – (χ=20.3) smooth 108-117 – (χ=113) 111-116 – (χ=112) 49-56 – (χ=52) 42-49 – (χ=46) 2 flared 1 first 3 variable blotched blotches, 4-5 scale uniform uniform equal or less Bangkok endemic uniform diameter equal Bangkok endemic uniform diameter less Vietnam endemi 327-669 – (χ=560) 317-809 – (χ=560) 0.2-0.26 – (χ=0.24) 0.17-0.26 – (χ=0.22) 23-26 – (χ=24.1) 21 – (χ=21.0) 19-21 – (χ=20.1) smooth 124-133 – (χ=128) 124-135 – (χ=127) 64-73 – (χ=69) 53-76 – (χ=63) 2 flared 1 first 3 small blotched sblotches, 4-5 scales uniform, some spots uniform diameter equal Tonlé Sap endemic and they are flared; the lateral-dorsal pattern of dark blotches (about five scale rows long) extends onto the ventral scales. See Table 1 and Fig. 1 for further comparisons to other taxa. Fifteen specimens labeled E. jagorii in several different collections did not fit this description and represent the new taxon described below. 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. 144 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: 116125 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 THE RAFFLES BULLETIN OF ZOOLOGY 2005 compressed. Female total length 435 mm, 96 mm tail (22.1%). Rostral scale pentagonal shallowly notched, and about twice as broad than tall. Nasal scales in contact, valvular nare located in center of nasal scale, nasal groove contacts first labial on each side. Left nasal completely divided, nasal groove contacts suture with right nasal, nasal scale diameter slightly greater than eye diameter. Hexagonal internasal single, posterior to nasals, contacts loreal on each side. Prefrontal scales contact loreal; diameter greater than eye diameter, posterior edges over lap the frontal. Frontal pentagonal, length less than interocular distance, width equal to orbit diameter. Paired parietals pentagonal, about 1.3 times longer than frontal (Fig. 2A). Quadrangular loreal longer than tall, in contact with first three upper labials. Ocular ring: a supraocular, a preocular, two postoculars; dorsal postocular about twice the size of lower postocular; subocular scales absent; fourth upper labial enters the orbit. Temporal formula 1+2+3, third row indistinguishable from the occipital scales. Upper labial scales number eight; tallest upper labial number seven (Fig. 2B). Lower labials number 10 on both sides; number six largest; first five lower labials contact first pair of chin shields. Two pairs of chin shields, anterior pair about equal to posterior pair, anterior pair has greater area; pair of smaller scales separates posterior pair of chin shields (Fig. 2C). Seven rows of gular scales between chin shields and anterior ventral scale. Scale rows 22-21-20. Scales in the first row at mid-body are 1.2 times taller than those in the second row. First six rows of dorsal scales very ovate; scales in row seven become more quadrangular. Ventrals are rounded, at mid-body about 3.5 times wider than nearby dorsal scale. Ventral scales number 119, have rounded edges, and are 3.54.0 times the height of a nearby dorsal scale. Subcaudal number 43/42; tail ends in terminal spine. Scales on the crown have scattered spots of pigment on a grey-brown background. Specimen faded from light and preservatives. Face and upper labials mottled with yellow and grey-brown, lower edges of upper labials yellow. Lower labials mottled with dark pigment on yellow background, chin uniform yellow. Outer edges of A B 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. Fig. 2. Drawing of Enhydris chanardi, USNM 83431. A. dorsal view of head; B. lateral view of head; C. ventral view of head. Drawings by Sarah Drasner. 145 Murphy & Voris: A new species of Enhydris 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. would also like to thank Bryan Stuart for access to his specimens, and his comments on these snakes. The following individuals and their institutions provided access to specimens and records and/or assistance with logistics while visiting their collections: Tanya Chanard and Yodchaiy Chuaynkem, National Science Museum (THNHM), Bangkok; Kumthorn Thirakhupt, Chulalongkorn University and Chulalongkorn Museum of Zoology (CUMZ), Bangkok; Lawan Chanhome, Queen Saovabha Memorial Institute, Thai Red Cross Society (QSMI), Bangkok; Colin McCarthy, British Museum of Natural History (BMNH), London; Linda Ford, Darrell Frost, David Dickey, Anthony Zammit and Philip Damiani, American Museum of Natural History (AMNH), New York; Jens Vindum, Alan Leviton, R Lucas, and Michelle Koo, California Academy of Sciences (CAS), San Francisco; Douglas Rossman, Jim McGuire, and Jeff Boundy, Louisiana State Museum of Zoology (LSUMZ), Baton Rouge; Ivan Ineich, Muséum National d’Histoire Naturelle (MNHN), Paris; Greg Schneider and Arnold Kluge, Museum of Zoology, University of Michigan (UMMZ), Ann Arbor; W. Ronald Heyer, Ronald Crombie, Addison Wynn, and Elyse Beldon, National Museum of Natural History (USNM), Washington; and Rainer Gunther at the Zoologisches Museum, Universität Humboldt, Berlin (ZMB). Emily Jensen and Sara E. Murphy assisted with data collection. LITERATURE CITED 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. Boulenger, G. A., 1896. Catalogue of the Snakes in the British Museum. Vol.3. Containing the Colubridae (Opisthoglyphae and Proteroglyphae), Amblycephalidae, and Viperidae. London: Trustees of the British Museum. 727 pp. Bourret, R., 1934. Notes herpétologiques sur l’Indochine française. IV. Sur une collection d’Ophidiens de Cochinchine et du Cambodge. Bulletin Générale de l’Instruction Publique, Hanoi, September (1): 1-20. Bourret, R., 1936. Les Serpents de L’Indochine. TomeII. Catalogue systématique descriptif. Toulouse: Henri Basuyau & Co. 505 pp. Campden-Main, S. M., 1970. A Field Guide to the Snakes of South Vietnam. Washington: Smithsonian Institution. iv+ 114 pp. Cochran, D., 1930. The herpetological collections made by Dr. Hugh M. Smith in Siam from 1923 to 1929. Proceedings of the United States National Museum, 77: 1-39. 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. Cox, M. J., P. P. van Dijk, J. Nabhitabhata, & K. Thirakhupt, 1998. A Photographic Guide to Snakes and Other Reptiles of Peninsular Malaysia, Singapore and Thailand. Sanibel Island: Ralph Curtis Publishing Co. 144 pp. ACKNOWLEDGMENTS Flower, S. S., 1899. Notes on a second collection of reptiles made in the Malay Peninsula and Siam, from November 1896 to September 1898, with a list of the species recorded from those countries. Proceedings of the Zoological Society of London, 1899: 1-452. Thanks go to Alan Resetar, Jamie Ladonski, Jennifer Mui, and Sarah Drasner for providing a great amount of expertise and assistance at the Field Museum (FMNH), Chicago. We 146 Cox, M. J., 1991. The Snakes of Thailand and Their Husbandry. Malabar, FL: Krieger Publishing Co. xxxviii+ 526 pp. Deuve, J., 1970. Serpents du Laos. Mémoirs O.R.S.T.O.M. (39). Pp. 1-251. Günther, A. C. L. G., 1864. Reptiles of British India. London: Ray Society, 1-452 pp. THE RAFFLES BULLETIN OF ZOOLOGY 2005 Gyi, K. K., 1970. A revision of colubrid snakes of the subfamily Homalopsinae. University of Kansas Publication, Museum of Natural History, Lawrence 20: 47-223. Smith, M. A., 1943. The Fauna of British India, Ceylon and Burma. Reptilia and Amphibia. Vol. 3. Serpentes. London: Taylor and Francis. 583 pp. Mocquard, M. F., 1907. Les reptiles de l’Indo-Chine. Paris: Angustin Challannel. 59 pp. Stuart, B. L., J. Smith, K. Davey, P. Din, & S. G. Platt., 2000. Homalopsine watersnakes: the harvest and trade from Tonle Sap, Cambodia. TRAFFIC, 18: 115-122. Morice, A., 1875. Coup d’oeil sur la faune de la Cochinchine française. Lyon: H. Georg. 101 pp. Murphy, J. C. & H. K. Voris., 1994. A key to the homalopsine snakes. The Snake, 26: 123-133. Tirant, G., 1885. Notes sur les reptiles et les batraciens de la Cochinchine et du Cambodge. Saigon: Gouvornement Press. 104 pp. Murphy, J. C., H. K. Voris, D. R. Karns, T. Chan-ard, & K. Suvurat., 1999. The ecology of the water snakes of Ban Tha Hin, Songkhla Province, Thailand. Natural History Bulletin of the Siam Society, 47: 129-147. Voris, H. K. & J. C. Murphy., 2002. Prey and predators of homalopsine snakes. Journal of Natural History, 36: 16211632. Nicholson, E., 1874. Indian Snakes. An Elementary Treatise on Ophiology, with a Descriptive Catalogue of the Snakes Found in India and the Adjoining Countries, Madras: Higginbotham and Co. 186 pp. APPENDIX 1. Comparative Material Peters, J. A., 1964. Dictionary of Herpetology. New York: Hafner Publishing Co. 392 pp. Peters, W. K. H., 1863. Über die von Hrn. Dr. F. Jagor in Siam gesamnulten Amphibiem. Monatsberichte der Preussischen Akademie der Wissenschaften zu Berlin 1863: 245-247 Saint Girons, H., 1972a. Les Serpents du Cambodge. Mémoires du Muséum National d’Histoire Naturelle, Paris. (N.S.). Zoologie, 74A: 1-170. Saint Girons, H., 1972b. Etude de la collection de serpents de Cochinchine du Docteur Morice. Nouvelles Archives du Muséum National d’Histoire Naturelle, Paris, 9: 3-12. [English Summary]. Enhydris enhydris – Borneo: ANSP 26401-02; Cambodia: FMNH 259359-67, 259372-73, 259375, 259377; India: ANSP 5091-94; FMNH 154593, 161446, 165097-102; Myanmar: KU 92471, 92476, 92478-80, 92482-83, 92485-86, 92488, 92491, 92557; Sri Lanka: CAS 12767; Vietnam: FMNH 259093-100. Enhydris innominata – Vietnam: BMNH 1938.1.13.1; FMNH 259101-07; 259247-54; ROM 37891, 37893. Enhydris jagorii – Thailand: BMNH 1928.12.18.1, 1930.1.1.3, 1948.1.2.27; FMNH 179114; THNHM 0924-0927, THNHM no number Bangkapi; ZMA 4746. Enhydris longicauda – Cambodia: FMNH 259255-281; MNHN 1948.96, 1970.526-540. 147