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| Ptyas bachmaensis S. N. Nguyen, Vo, Orlov, Phan, Le, L. T. Nguyen, Tran, Murphy & Che, 2024 |
Abstract
Rat snakes (genus Ptyas) include 13 large Asian species with sizes reaching 3.8 m. For more than 100 years, no new species have been discovered in this genus. Here, we describe a new Ptyas from central Vietnam based on morphological data and nucleotide sequences from the MT-CYB gene. Ptyas bachmaensis sp. nov. is diagnosed by the following morphological characters: large-sized snake (largest total length 2401 mm in adult male); body scale rows in even numbers, 16-16-14 rows; two medial vertebral scale rows distinct; two and two or four medial scale rows keeled on middle and posterior parts of body, respectively; ventrals 194–199; subcaudals 132–138; supralabials 8, fourth and fifth entering orbit; maxillary teeth 28 or 29; hemipenis spinose and unforked, reaching 12th subcaudal; cloacal plate divided; lateral side of tail black, without a bright stripe. The new species forms an independent clade on the phylogenetic tree and differs from its congeners by an uncorrected p-distance in MT-CYB sequences of at least 5.7%.
Keywords: Bach Ma National Park, Thua Thien - Hue Province, Kon Tum, Ptyas bachmaensis, Ptyas nigromarginata, Zaocys
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| Holotype of Ptyas bachmaensis sp. nov. (ITBCZ 8628) in life Photo by Sang N. Nguyen. |
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| Paratypes of Ptyas bachmaensis sp. nov. in life A: Gravid female ITBCZ 8507; B: Juvenile ZISP 32661. Photos by Sang N. Nguyen (A) and Nikolai L. Orlov (B). |
Ptyas bachmaensis sp. nov.
Diagnosis: Ptyas bachmaensis sp. nov. is distinguished from all congeners by the unique combination of the following morphological characters: large-sized snake (largest TL 2401 mm in adult male); body scale rows in even numbers, 16 rows at neck and midbody, 14 rows before vent; two medial vertebral scale rows throughout; two and two or four medial scale rows keeled on middle and posterior parts of body, respectively; ventrals 194–199; subcaudals 132–138; supralabials 8, fourth and fifth entering orbit; maxillary teeth 28 or 29; hemipenis spinose and unforked, reaching 12th subcaudal; cloacal plate divided; lateral side of tail black, without a bright stripe.
Etymology: The specific epithet bachmaensis is a toponym derived from the Bach Ma Mountain where the holotype of the new species was discovered. We recommend “Bach Ma green rat snake” and “Rắn ráo xanh Bạch Mã” as the common English and Vietnamese names of the new species, respectively.
Sang Ngoc Nguyen, Ba Dinh Vo, Nikolai L. Orlov, Khanh Duy Phan, Manh Van Le, Luan Thanh Nguyen, An Thien Tran, Robert W. Murphy, Jing Che. 2024. A New Species of Green Rat Snake (Squamata: Colubridae: Ptyas) from Vietnam. Zoological Research: Diversity and Conservation. DOI: doi.org/10.24272/j.issn.2097-3772.2024.013
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