Thursday, December 5, 2024

[Herpetology • 2024] Colubroelaps adleri • A New endemic insular species of the Genus Colubroelaps (Serpentes: Colubroidea) from Khanh Hoa Province, Vietnam


Colubroelaps adleri  
Poyarkov, Bragin & Nguyen, 2024  
 
Adler’s lace snake | Rắn hổ nước Át-Lơ  ||  DOI: doi.org/10.3897/herpetozoa.37.e137809 

Abstract
A new species of the poorly known genus Colubroelaps Orlov, Kharin, Ananjeva, Nguyen & Nguyen, 2009, is described based on a single female specimen collected from Hon Tre Island, Khanh Hoa Province, Vietnam. The new species, Colubroelaps adleri sp. nov., can be distinguished from its sister species Colubroelaps nguyenvansangi Orlov, Kharin, Ananjeva, Nguyen & Nguyen, 2009 by the following combination of morphological characters: small body size (TL 402 mm); tail relatively short (ratio TaL/TL 0.10); dorsal scales in 14–14–14 rows; supralabials six, third and fourth entering orbit; infralabials seven; loreal present; ventral scales 234; subcaudals 30, all divided; cloacal plate divided; dorsal coloration pale brown, with narrow and interrupted dark stripe along spine; body flanks dark-gray lacking bluish iridescence; ventrally uniform off-white; head black with rostral, nasals, prefrontals, preoculars, loreal, and the two anterior supralabials, as well as anterior parts of supraoculars and frontal dirty yellowish-brown with dark-brown spots. This discovery represents the second known species of the genus Colubroelaps and the first record of the genus in the coastal areas of southern-central Vietnam. The new species is likely micro-endemic to the small island of Hon Tre within Nha Trang Bay in Khanh Hoa Province, Vietnam, at an elevation of 30 m a.s.l., and was recorded only from the heavily disturbed secondary forest area of the island. The new species is under threat due to the intensifying development of tourist infrastructure on Hon Tre Island. We suggest that the new species be considered Endangered (EN) following the IUCN’s Red List categories.

Key Words: Colubroelaps adleri sp. nov., conservation, Hon Tre Island, morphology, Nha Trang Bay, taxonomy

The holotype of Colubroelaps adleri sp. nov. in life (ZMMU Re-18000, adult female) from Hon Tre Island, Khanh Hoa Province, Vietnam.
A. Dorsal view of the head; B. Ventral view of the head; C. Lateral view of the right side of the head; D. Lateral view of the left side of the head; E. Ventral view of the tail; F. Ventral view of the body; G. Dorsal view of the body.
Scale bars: 5 mm (A–D); 10 mm (E–G). Photographs by A. M. Bragin.

Two species of the genus Colubroelaps in life.
A. Colubroelaps adleri sp. nov., holotype ZMMU Re-18000, adult female from Dam Bay Research Station, Hon Tre Island, Khanh Hoa Province, Vietnam;
B. Colubroelaps nguyenvansangi, ZMMU Re-15485, adult male from Cat Tien NP., Tan Phu District, Dong Nai Province, Vietnam.
Photographs by: A. M. Bragin (A); E. A. Galoyan (B).


 Colubroelaps adleri sp. nov.
 
Diagnosis: Colubroelaps adleri sp. nov. can be distinguished from C. nguyenvansangi by the following combination of morphological characters: body size small (TL 402 mm); tail relatively short (ratio TaL/TL 0.10); dorsal scales in 14–14–14 rows; supralabials six, third and fourth entering orbit; infralabials seven; loreal present; ventral scales 234; subcaudals 30, all divided; cloacal plate divided; dorsal coloration pale brown with narrow and interrupted dark stripe along spine; body flanks dark gray lacking bluish iridescence; ventrally uniform off-white; head black with rostral, nasals, prefrontals, preoculars, loreal, and the two anterior supralabials, as well as the anterior parts of supraoculars and frontal shields dirty yellowish-brown with dark brown spots.


Etymology: The species epithet ‘adleri’ is a patronymic adjective in genitive singular. We name the new species in honor of Dr. Kraig Adler, Professor Emeritus at Cornell University (New York, USA), in recognition of his outstanding support to the international herpetological community as well as his remarkable scientific contribution to Asian herpetology. We suggest the following common names for the new species: “Adler’s lace snake” (in English), “Shnurkovaya zmeya Adlera” (Шнурковая змея Адлера, in Russian), and “Rắn hổ nước Át-Lơ” (in Vietnamese).


 Nikolay A. Poyarkov, Andrey M. Bragin and Tan Van Nguyen. 2024. A New endemic insular species of the Genus Colubroelaps (Squamata, Serpentes, Colubroidea) from Khanh Hoa Province, Vietnam. Herpetozoa. 37: 379-390. DOI: doi.org/10.3897/herpetozoa.37.e137809