Abstract
A newly discovered species of homalopsid snake from the genus Gyiophis Murphy & Voris is described from the lowlands of Mawlamyine District in Mon state, southeastern Myanmar. Gyiophis salweenensis sp. nov. is presumed to be closely related to G. maculosa Blanford and G. vorisi Murphy based on the similarities in pholidosis and patterning but can be separated from G. maculosa by the shape of its first three dorsal scale rows that are square, ventral scale pattern that lacks a central spot, and a faint stripe on dorsal scale rows 1–4. It can be further distinguished from G. vorisi by its lower number of ventral scales (129 vs. 142–152), lower number of subcaudals (30/29 vs. 41–58), narrow rostral scale, and having more rows of spots on the dorsum (four vs. three). A preliminary molecular analysis using 1050 base pairs of cytochrome b (cytb) recovered G. salweenensis sp. nov. as the sister species to the Chinese Mud Snake (Myrrophis chinensis). G. maculosa and G. vorisi were unavailable for the analysis. The discovery of G. salweenensis sp. nov. highlights the need for more surveys into the herpetological diversity of eastern Myanmar which remains very much underestimated.
Keywords: Reptilia, phylogeny, Enhydris, homalopsid, conservation, endemic biodiversity, Burma
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| Holotype of Gyiophis salweenensis sp. nov. in life.
Photograph by Evan Quah.
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Etymology. The specific epithet salweenensis is in reference to area where the holotype was found which is close to the vicinity of the Salween River near the city of Mawlamyine. The suffix ensis is a Latin derivation meaning “from” or “inhabiting.” It renders the specific epithet an adjective that must be in grammatical accord with the gender of Gyiophis.
Distribution: Gyiophis salweenensis sp. nov. is only known from the type locality near Sanpel Cave, Mon State, Myanmar. It is expected to be wider ranging throughout the Salween River Basin and found wherever appropriate habitat occurs.
Natural history: The holotype was found at approximately 1930 hours crossing a narrow dirt road between flooded fields that we presume to be its natural habitat. The weather was overcast and it rained later that night. Many other species of homalopsids are semiaquatic and commonly found in streams, rivers, ponds, and flooded rice fields (Murphy 2007a; Stuebing et al. 2014). Gyiophis salweenensis sp. nov. is expected to share a similar life history and the valvular nostrils located dorsally on the snout indicate this species probably spends a large part of its life in the water. Homalopsid snakes such as Enhydris enhydris, Homalopsis buccata (Linnaeus, 1758) and Hypsiscopus plumbea have been observed crawling on land and crossing roads during wet weather (Voris & Karns 1996; Lim & D’Rozario 2009; EQSH personal obs.) and the holotype of G. salweenensis sp. nov. could have been dispersing to a new area as well. The holotype also had a puncture wound on its back which might have come from an encounter with a predator such as a heron.
Quah, Evan S. H., L. L. Grismer, P. L. Wood, Jr., Myint K. Thura, Thaw Zin, Htet Kyaw, Ngwe Lwin, Marta S. Grismer & M. L. Murdoch. 2017. A New Species of Mud Snake (Serpentes, Homalopsidae, Gyiophis Murphy & Voris, 2014) from Myanmar with A First Molecular Phylogenetic Assessment of the Genus. Zootaxa. 4238(4): 571–582. DOI: 10.11646/zootaxa.4238.4.5
