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| (upper) Holotype of Pareas victorianus Vogel, Nguyen & Poyarkov (A-D) Pareas monticola in life. in Vogel, Nguyen, Zaw & Poyarkov, 2020 |
ABSTRACT
A review of the taxonomic status of Pareas monticola (Himalaya slug snake) based on morphological and molecular data revealed a new species from Myanmar. Pareas victorianus sp. nov. Vogel, Nguyen and Poyarkov from the Nat Ma Taung National Park in western Chin State is suggested to be a sister species to P. monticola sensu stricto, and can be separated from the latter by the absence of preoculars, by the subocular separating the eye from the labials, by seven keeled dorsal scale rows at midbody, by a lower number of ventrals (164) and by a lower number of subcaudals (58). Another new population from the Hkakabo Razi National Park in the northernmost part of Kachin State was previously confused with P. monticola, but can be differentiated from the latter and from Pareas victorianus sp. nov. by the presence of preoculars, by the number of ventrals (182) and subcaudals (71), by the absence of dark postorbital stripes, and by the lateral and ventral surfaces of the head with dense brown dusting; we herein refer to this population as Pareas sp. pending further molecular data confirming its taxonomic status. We also confirm the occurrence of P. monticola sensu stricto in Myanmar based on specimens from Kachin State and Sagaing Division. Furthermore, we discuss the actual distribution, genetic differentiation and taxonomic problems of P. monticola species complex. Our work brings the total number of species recognised within the genus Pareas to 20, of which nine species occur in Myanmar. An updated key for the Pareas species of Myanmar is provided.
KEYWORDS: Pareas victorianus sp. nov., distribution, taxonomy, Chin, Kachin, Nat Ma Taung National Park, Hkakabo Razi National Park
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| Figure 1. Map showing distribution of the Pareas monticola species complex and locations of the studied populations. Circles denote localities for which both DNA and morphological data were examined; diamonds denote localities for which only morphological data were available; triangles denote populations for which only DNA data were available; a dot in the centre of an icon indicates a type locality; question marks denote unconfirmed and historical records. Localities. Pareas monticola: BHUTAN: 1 -Bhutan, no exact locality (Lenz 2012); BANGLADESH: 2 -Lawachara NP, Moulvibazar, Sylhet (Das and Das 2017; Hakim et al. 2020); INDIA: 3 -Darjiling, West Bengal; 4 -Khasi Hills, Meghalaya; 5 -Jampui Hills, Tripura; 6 -Mizoram; 7 -Naga Hills, Assam (type locality of Dipsas monticola Cantor, 1839); 8 -Orang, Assam (Deepak et al. 2020); 9 -Abor Hills, Arunachal Pradesh; 10 -Mishmi Hills, Arunachal Pradesh; MYANMAR: 11 -Indawgyi NR, Myitkyina, Kachin; 12 -Banmauk, Sagaing; CHINA: 13 -'Medog' (= Motuo), Xizang (Guo et al. 2011; Li et al. 2020; Wang et al. 2020); 14 -Linzhi, Motuo, Xizang; 15 -Longchuan, Yunnan (Yang and Rao 2008); 16 -Pingbian, Yunnan (Wang et al. 2020); VIETNAM: 17 -'Chapa' (= Sa Pa), Lao Cai (Bourret 1936); 18 -Tam Dao, Vinh Phuc (Orlov et al. 2003); Pareas sp.: MYANMAR: 19 -Hkakabo Razi NP, Putao, Kachin; Pareas victorianus sp. nov.: MYANMAR: 20 -Nat Ma Taung Mt., Mindat, Chin (type locality). Photo showing P. monticola from Sagaing, Myanmar, by N.A. Poyarkov. Abbreviations: BAN. = Bangladesh; BHU. = Bhutan. |
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| Figure 2. Bayesian inference tree of the Pareas monticola species complex derived from the analysis of 1126 bp of cyt b, 678 bp of ND4 and 734 bp of c-mos gene fragments. For voucher specimen information and GenBank accession numbers see Table 2. Light blue and dark blue denote Pareas monticola and Pareas victorianus sp. nov., respectively; values in parentheses after locality names correspond to locality numbers in Figure 1 and Table 2. Black circles indicate highly supported nodes; empty circles indicate moderately supported nodes (see Materials and methods); numbers at tree nodes correspond to PP/BS support values, respectively. Photo showing P. monticola from Sagaing, Myanmar, by N. A. Poyarkov. |
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| Figure 4. Comparison of head scalation in lateral view of the type specimens of Pareas monticola complex members: a: Pareas monticola holotype (BM(NH) 1946.1.20.5, adult male); b: Pareas victorianus sp. nov. holotype (CAS 224415, adult male); c: Pareas sp. from Kachin State (CAS 235254, adult female). Drawings by L.B. Salamakha. |
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| Figure 3. Holotype of Pareas victorianus sp. nov. in preservative (CAS 224415, adult male): a-b: Dorsolateral and ventral view of body, respectively; c-f: head in lateral right, lateral left, dorsal, and ventral aspects, respectively. Photos by G. Vogel. |
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| Figure 6. Photos of Pareas monticola in life. (a) Jampui Hills, Tripura State, India (not collected); (b) Mizoram State, India (not collected); (c-d) Banmauk Township, Sagaing Division, Myanmar (ZMMU R-16631-16632, respectively). Photos by G. Vogel (a, b); N.A. Poyarkov (c, d). |
Gernot Vogel, Tan Van Nguyen, Than Zaw and Nikolay A. Poyarkov. 2020. A New Species of the Pareas monticola Complex (Squamata: Serpentes: Pareidae) from Chin Mountains with Additions to the Pareas Fauna of Myanmar. Journal of Natural History. 54(39-40); 2577-2612. DOI: 10.1080/00222933.2020.1856953
