 |
| Lycodon duytan Nguyen, Poyarkov & Vogel, 2025 |
Abstract
The Red-banded Wolf Snake, Lycodon rufozonatus Cantor, 1842 has a complex taxonomic history. In this study, an integrative taxonomic approach is applied, incorporating morphological analyses, cytochrome b mitochondrial gene sequencing, and a re-examination of available type material to clarify the longstanding taxonomic uncertainties within Lycodon rufozonatus species complex. Our findings restrict the distribution of Lycodon rufozonatus to mainland China, Taiwan, the Korean Peninsula, Russia (southern Primorsky Krai), Japan (Tsushima Islands, Nagasaki), and northeastern Vietnam. Additionally, Dinodon rufozonatum walli Stejneger, 1907, previously considered a subspecies, is elevated to full species status as Lycodon walli stat. nov., endemic to the Miyako and Yaeyama Islands, Okinawa, Japan. Furthermore, a new cryptic species is described from north-central Vietnam, Lycodon duytan sp. nov., which is distinguished from L. rufozonatus and L. walli stat. nov. by differences in body scalation, colouration, and the number of keeled dorsal scales. Our findings highlight the underestimated diversity within Lycodon and contribute to a more refined understanding of its taxonomy. This study increases the total number of recognised Lycodon species to 78, underscoring the importance of integrative approaches in resolving taxonomic complexities within the genus.
Key words: Asia, cryptic species, cytochrome b, morphology, taxonomy, Lycodon duytan sp. nov.
 |
| Lycodon rufozonatus in life (all not collected) – China: from Hangzhou, Zhejiang (A); from Beijing, Beijing (B); from Chengdu, Sichuan (C); from Jian, Jiangxi (D); from Lu’an, Anhui (E); from Nanjing, Jiangsu (F); from Wuhan, Hubei (G); from Shenzhen, Guangdong (H); from Chuxiong, Yunnan (I); from Kunming, Yunnan (J); – South Korea: from Anyang, Gyeonggi-do (K); from Chuncheon, Gangwon (L). Photos by J. Hong (A); M.L. Li (B, G); G. Vogel (C); A. Tianji (D); Y.Y. Zhang (E); A. Borzée (F); G.L. Wu (H); Y.X. Wu (I); C. Jin (J); K.D. Wook (K); Y. Shin (L) |
 |
| Lycodon rufozonatus in life (all not collected) – South Korea: from Ongjin, Incheon (A); from Sancheong, Gyeongsangnam (B) – Japan: from Tsushima, Nagasaki (C); – Vietnam: from Tay Yen Tu NR, Bac Giang (D); – Taiwan, China: from Taoyuan (E-G); from Hualien (H); from Taichung (I); from Nantou (J-L). Photos by A. Borzée (A); Y. Shin (B); Chouenyu (C); B.T. Nguyen (D); C.W. You (E-L). |
 |
| Lycodon walli stat. nov. in life (all not collected): – Ryukyus, Japan: from Miyako Is (A, B); from Ishigaki Is (C); from Kohama Is (D); from Irimote Is (E); from Huroshima (F); from Taketomi Is (G); and Yonaguni Is (H). Photos by G. Vogel (A); C.W. You (B); K. Ito (C-H); S. Kanao (D). |
Lycodon walli (Stejneger, 1907), stat. nov.
Etymology. According to Stejneger (1907), the subspecies is named for Captain Frank Wall (1868–1950), of the Indian Medical Service, author of “A prodromus of the snakes hitherto recorded from China, Japan, and the Loo Choo Islands”, as well as many papers on Indian snakes.
We recommend the following common names for this species: Sakishima Wolf Snake (in English); Sakishima Grosszahnnatter (in German); サキシママダラ “Sakishimamadara” (in Japan); Окинавский краснопоясный волкозуб “Okinavskiy krasnpoyasnyi volkozub” (in Russian).
 |
| Lycodon duytan sp. nov. in life – specimen DTU 541 (paratype, adult female): general dorsal view (A); general ventral view (B); lateral view of the head, right side (C); lateral view of the head, left side (D); dorsal view of the head (E) – specimen DTU 544 (paratype, adult female): general dorsal view (F). Photos by T.V. Nguyen (A-E); T. Warfel (F). |
Lycodon duytan sp. nov.
Diagnosis. A larger-sized species, with a maximum snout-vent length of up to 980 mm; loreal usually contacting the eye; dorsal scale rows 17–17–15; upper four or five and vertebral dorsal scale rows keeled; 217–230 ventrals; 80–95 subcaudals, paired; cloacal plate undivided; eight supralabials with 3–5 touching the eye; 1 preocular, 2 postoculars; temporals 2+2; dorsal crossbands narrow, separating ground colour into ellipse patches, pinkish-orange colour, 54–72 crossbands on body and tail; head black, the plates conspicuously margined with pinkish-orange; venter reddish-orange.
Etymology. The species name is derived from the Duy Tan Modernisation Movement (Phong trào Duy Tân) of 1906–1908 in Vietnam, a significant historical reform movement for the modernisation of the country and the society. The specific epithet also acknowledges Duy Tan University, the institution affiliated with the first author, which provided support for this research.
We recommend the following common names for this species: Duy Tan Wolf Snake (in English); Duy Tan Grosszahnnatter (in German); Rắn khuyết Duy Tân (in Vietnamese); Южный краснопоясный волкозуб “Yuzhnyi krasnopoyasnyi volkozub” (in Russian).
Tan Van Nguyen, Nikolay A. Poyarkov and Gernot Vogel. 2025. Taxonomic Reassessment of the Lycodon rufozonatus species complex (Serpentes, Colubridae), with re-evaluation of Dinodon rufozonatum walli, and Description of A New Species from north-central Vietnam. ZooKeys. 1251: 293-322. DOI: doi.org/10.3897/zookeys.1251.157817 (15/9/2025)
