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| Myrrophis dakkrongensis Nguyen, Le, Lathrop, Vo, Murphy & Che, 2024 |
Abstract
Homalopsid snakes of the genus Myrrophis include only two species distributed in southern China and northern Vietnam. Here, we describe a third species from southern Vietnam based on morphological data and nucleotide sequences from the mitochondrial gene cyt b. Myrrophis dakkrongensis sp. nov. is diagnosed by the following morphological characters: Medium-sized mud snake (largest total length 452 mm); internasal single and distinctly separated from loreals; dorsal scales smooth, in 23 rows at midbody, reduced to 19 or 20 rows before vent; ventrals 133–138; subcaudals 34–42, paired; cloacal plate divided; supralabials 8, fourth entering orbit; second pair of chin-shields small and oblique; maxillary teeth 17 or 18; gland-like tubercles present in the cloacal region; hemipenis short, forked and spinose, reaching 7th subcaudal; dorsum dark brown to black; and a white or yellow to orange lateroventral stripe present. The new species differs from its congeners by an uncorrected p distance in cyt b sequences of at least 10.5%.
Key words: Dak Nong Province, Gyiophis, hemipenis, Mekong River, mitochondrial DNA, Myanophis, Myrrophis bennettii, Myrrophis chinensis, Myrrophis dakkrongensis
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| Holotype of Myrrophis dakkrongensis sp. nov. (ITBCZ 6695) in life. |
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| Holotype of Myrrophis dakkrongensis sp. nov. (ITBCZ 6695). A–C Dorsal, ventral, and lateral views of head, respectively; D ventral view; E cloacal region showing three yellow gland-like tubercles on both sides; F lateral view of right maxillary teeth. |
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| Paratypes of Myrrophis dakkrongensis sp. nov. and habitats of the new species. A Paratype ITBCZ 6694; B, C paratype ITBCZ 6700 and its hemipenes; D rubber plantation where the holotype was collected; E wetland in forest where paratype ITBCZ 6700 was collected. |
Myrrophis dakkrongensis sp. nov.
Diagnosis: Myrrophis dakkrongensis sp. nov. is distinguished from all of its congeners by the unique combination of the following morphological characters: medium-sized mud snake (largest TL 452 mm in adult female); internasal single and not in contact with loreals; dorsal scale rows 23-23-19 or 23-23-20, smooth; tail short (TaL/TL ratio 0.15–0.16 in males and 0.14 in female); ventrals 134–138 in males and 133 in female; subcaudals 39–42 in males and 34 in female; 8 supralabials, fourth entering orbit; second pair of chin-shield small, oblique, and in contact with two infralabials; 17 or 18 maxillary teeth; hemipenis short, forked and spinose, reaching 7th subcaudal; cloacal plate divided; gland-like tubercles present in the cloacal region; dorsum dark brown to black; and white or yellow to orange lateroventral stripe present.
Etymology: The specific epithet dakkrongensis is a toponym derived from the Dak Krong River system where the new species was discovered. We recommend “Dak Krong mud snake” and “Rắn bồng đắk krông” as the common English and Vietnamese names of the new species, respectively.
Sang Ngoc Nguyen, Manh Van Le, Amy Lathrop, Thi-Dieu-Hien Vo, Robert W. Murphy and Jing Che. 2024. A New Species of Mud Snake (Squamata: Homalopsidae: Myrrophis) from southern Vietnam. Vertebrate Zoology. 74: 221-233. DOI: 10.3897/vz.74.e116992
