PROCEEDINGS OF THE BIOLOGICAL SOCIETY OF WASHINGTON 131:19–35. Published 12 January 2018. Rediscovery of Xenochrophis bellulus (Stoliczka, 1871) from Myanmar (Serpentes: Natricinae) with comments on its taxonomic status Justin L. Lee,* Gernot Vogel, Aryeh H. Miller, and George R. Zug (JLL) College of Computer, Mathematical and Natural Sciences, University of Maryland, College Park, MD, 20742, U.S.A., e-mail: [email protected]; (GV) Society for Southeast Asian Herpetology, Im Sand 3, D-69115 Heidelberg, Germany, e-mail: [email protected]; (AHM) Department of Biology, University of North Carolina Asheville, Asheville, NC 28804, U.S.A.: e-mail: [email protected]; (GRZ) Department of Vertebrate Zoology, National Museum of Natural History, Smithsonian Institution, P.O. Box 37012, Washington, District of Columbia, 20013-7012, U.S.A., e-mail: [email protected] Abstract.—Xenochrophis bellulus (Stolickza, 1871) was described as Tropidonotus bellulus based on a single specimen collected from Myanmar in the late 19th century. Since then the holotype has been lost, and the species has been transferred to several genera in the subfamily Natricinae including Natrix, Sinonatrix and finally Xenochrophis based on one museum specimen matching the original description. Herpetofaunal surveys of the Moyingyi Wildlife Sanctuary and vicinity, Bago Region, Myanmar revealed three individuals obtained in 2001 and 2003 that match the type description of X. bellulus. This small series of newly collected specimens allows us to redescribe this species based on all known material, provide a description of the hemipenis, designate a neotype and comment on its taxonomic status. Keywords: biodiversity, morphology, natural history, rare species, rede- scription, snakes, Southeast Asia, taxonomy Myanmar has experienced an increase semi-aquatic snake found in Southeast in herpetological research with the addi- Asia (Uetz 2017). Of these, only the tion of new surveys that have helped fill in Xenochrophis piscator group has received sampling gaps and led to the discovery of recent taxonomic treatment (Zug et al. several endemic snake species (Slowinski 2006, David & Vogel 2012). Perhaps the &Wu¨ster 2000, Slowinski et al. 2001, most poorly known of all species within Murphy 2007, Zug et al. 2011, Vogel & the genus is Xenochrophis bellulus.This Van Rooijen 2011, Vogel et al. 2012, species was described as Tropidonotus Vogel 2015; Quah et al. 2017). Still, bellulus in 1871 by herpetologist Ferdi- Myanmar remains poorly known herpe- nand Stoliczka, who illustrated the taxon tologically, and many species from the on the basis of a single specimen (Zoo- country are poorly represented in muse- logical Society of India [ZSI number um collections. unknown] ¼ holotype now considered to The genus Xenochrophis Gu¨nther, 1864 be lost according to Das et al. [1998]) currently consists of twelve species of collected from ‘‘Prome, near Pegu, Bur- ma’’ (¼ Pyay, Bago Region, Myanmar). * Corresponding author. The specimen, unsexed, was ‘‘16 ½ DOI: 10.2988/17-00025 inches, of which the tail is 5 inches’’ (¼ 20 PROCEEDINGS OF THE BIOLOGICAL SOCIETY OF WASHINGTON 419 mm Total Length, 127 mm Tail some insecurity’’ to the genus Xenochro- Length) and was described by its unique phis Gu¨nther, 1864, which they believed suite of morphological characteristics and shared similar traits. However, Dowling color pattern, especially the ‘‘sides of the & Jenner (1988) as well as Rao & Yang neck with transverse yellowish bars, the (1998) continued recognizing this species skin next to the bars being intensely as member of the genus Sinonatrix.These black’’. Stoliczka (1871) acknowledged latter authors likely missed Malnate & the distinctiveness of this species, but Underwood’s taxonomic decision for this noted some similarities with other species species, as it was only included in the in the genus Tropidonotus (currently in appendix of their publication and was Xenochrophis). Theobald (1876) and Bou- published the same year as Dowling and lenger (1890) continued to recognize the Jenner’s. species as T. bellulus.However,Boulenger Between 2001 and 2003, the Myanmar (1893) synonymized this species with Herpetological Survey (MHS) collected Tropidonotus trianguligerus F. Boie, 1827 three specimens of an unidentified natri- (¼ now Xenochrophis trianguligerus)with cine snake. These snakes were deposited in some reservations (a question mark is the National Museum of Natural History present before the synonym). He had no (USNM) and the California Academy of specimen at hand at the time and likely Sciences (CAS) herpetology collections. judged the identity from the illustration Further investigation shows that these provided by Stoliczka. This synonymy specimens match the type description of was repeated by Wall (1926) who reported Xenochrophis bellulus, giving us the oppor- a specimen (BMNH 1930.5.8.182) as tunity to report important new data on Natrix trianguligerus from ‘‘Minhla, this poorly known species. Thayetmyo District, Burma’’ (¼ Minhla, Magway Region, Myanmar). In his re- view of Burmese snake fauna, Smith Materials and Methods (1943) removed T. bellulus from synony- myandplaceditinthegenusNatrix Morphological data taken from the Laurenti, 1768. Smith also reported an- three specimens collected in Bago Region, other specimen (BMNH 1938.2.2.1) col- Myanmar by the MHS in 2003 and from lected ‘‘near Rangoon’’ (¼ Yangon) and the only other known specimen BMNH tentatively recognized the specimen re- 1938.2.2.1 were compared with the original ported by Wall (1926) as Natrix bellula. description of the species. The specimen Later, Natrix bellula was moved to the BMNH 1930.5.8.182 reported by Wall newly created Sinonatrix by Rossman & (1926) is known only from its skull and Eberle (1977). The latter authors did not was not examined by us. Specimens examine a preserved specimen for this deposited by MHS were collected in the species and likely moved it to this genus field by hand and preserved in a 10% based on descriptions in the literature. formalin mixture before being transferred Malnate & Underwood (1988), while to 70% ethanol. Tissue was collected from investigating species of Tropidonophis the liver and heart before fixation and Jan, 1863, identified differences between stored in 95% ethanol for future molecular the only other available specimen of phylogenetic analysis. Sinonatrix bellula (presumably BMNH Sex was determined based on a small 1938.2.2.1) and other members of the ventral incision directly posterior to the genus and described some aspects of the cloaca. Body measurements including taxon’s viscera and hemipenial morphol- Snout-Vent-Length (SVL), Tail Length ogy. They moved Sinonatrix bellula ‘‘with (TailL) and Total Length (TotalL) were VOLUME 131 21 measured using a flexible ruler to the Smithsonian Institution, Washington, nearest millimeter. Head Length (HeadL), D.C.,U.S.A.(USNM);ZoologischesMu- Head Width (HeadW) and length/width of seum fu¨r Naturkunde der Humboldt- the chin shields, were measured using a Universita¨t zu Berlin, Berlin, Germany slide-caliper to the nearest 0.1 of a (ZMB); Zoological Survey of India, Kol- millimeter. Ventral scale counts were made kata, West Bengal, India (ZSI); and according to Dowling (1951), but data Zoologische Staatssammlung, Mu¨nchen, from Stoliczka (1871) and Smith (1943) Germany (ZSM). include preventral scales and thus should be 1 or 2 ventrals lower. The tail tip was not counted for the total number of Results subcaudals. Dorsal scale row counts were made at one head length behind the head, Morphological analyses of these three midbody and one head length before the new specimens match those in the descrip- vent. Values for head scutellation are given tion of the holotype made by Stoliczka in left/right order. Maxillary teeth were (1871) and the only other known specimen carefully counted in-situ on the right side of X. bellulus (BMNH 1938.2.2.1). The of the mouth by removing the exterior gum discovery of new material prompts us to surface. The hemipenial description is redescribe the taxon. While the written based on specimen USNM 587199. The description of Tropidonotus bellulus by partially everted left organ was dissected, Stoliczka (1871) is detailed enough to then prepared, following the procedures identify it with certainty, we believe that recommended by Pesantes (1994), Myers the designation of a neotype is necessary in & Cadle (2003) and Zaher & Prudente order to clarify its nomenclatural status. (2003). Alizarin red staining was used to We offer the following reasons that justify reveal calcified structures as recommended our decision: (1) the name Tropidonotus by Harvey & Embert (2008). Terminology bellulus has been synonymized with Tropi- for hemipenial morphology follows Dow- donotus (¼ Xenochrophis) trianguligerus, ling & Savage (1960). Comparisons with causing some taxonomic confusion, (2) other species of the genus Xenochrophis the name Tropidonotus bellulus and Xen- and Sinonatrix were based on pertinent ochrophis bellulus must be re-associated literature, including Guo et al. (2014), with specimens present in Myanmar that Malnate (1960), Malnate & Minton have transverse yellowish bars anteriorly, (1965), Malnate & Underwood (1988), with the skin next to the bars being Pauwels et al. (2001), Smith (1943), Sto- intensely black; and (3) the holotype of liczka (1871), Vogel & David (2012) and Tropidonotus bellulus is lost and several Zug et al. (2006) as well as from examined detailed efforts have failed to locate