Channa nox, a new channid fish lacking a pelvic fin from Guangxi, China Chun-Guang Zhang 1 , Prachya Musikasinthorn 2* *, and Katsutoshi Watanabe 3 ** 1 Institute of Zoology, Chinese Academy of Sciences, 19 Zhongguancun Lu, Haidian, Beijing 100080, China (fish@panda.ioz.ac.cn) 2 Laboratory of Ichthyology, Tokyo University of Fisheries, 4-5-7 Konan, Minato-ku, Tokyo 108-8477, Japan 3 Ocean Research Institute, The University of Tokyo, 1-15-1 Minamidai, Nakano-ku, Tokyo 164-8639, Japan * Present address: Kasetsart University Museum of Fisheries, Faculty of Fisheries, Kasetsart University, Chatuchak, Bangkok 10900, Thailand (ffispcm@ku.ac.th) ** Present address: Nara Women’s University, Faculty of Science, Kitauoya-nishimachi, Nara 630-8506, Japan (e-mail: watanak@cc.nara-wu.ac.jp) Received: January 18, 2001 / Revised: November 2, 2001 / Accepted: December 12, 2001 Abstract A new species of channid fish, genus Channa, is described from 7 specimens collected from the vicinity of Hepu, Guangxi Province, southern China. The new species, Channa nox, is distinguished from all other channid species by the following combination of characters: absence of pelvic fins, small rounded head (22.1%–26.8% SL), narrow interorbital width (19.6%–26.7% HL), short snout length (3.6%–5.1% SL), predorsal and prepectoral lengths (26.9%–28.4% SL and 24.8%–28.3% SL, respec- tively), 47–51 dorsal fin rays, 31–33 anal fin rays, 55–63 lateral line scales, 5.5–6.5 scales above lateral line, 9–13 cheek scales, 53–55 total vertebrae, 1 or 2 scale(s) on each side of lower jaw undersurface, the black upper half of body with 8–11 irregular (often anteriorly pointed V-shaped) bands or blotches, a large white-rimmed black ocellus on caudal peduncle and sparse white spots on the dark brown body and dorsal and caudal fins, as well as the shape of the hyomandibular process of the suprabranchial organs. Channa nox is sympatrically distributed with its morphologically most similar congener, C. asiatica. Key words Channidae · Guangxi · Hepu · China · New species from radiographs. Vertebral counts, including the urostyle, were taken from radiographs. Principal component analysis (PCA) was performed from a correlation matrix of meristic counts for comparison with morphologically similar species. The suprabranchial organ was examined in two dissected specimens. Channa nox sp. nov. (Figs. 1–4) Holotype. IOZCAS (Institute of Zoology, Chinese Academy of Sciences, China) 70028, 189.3mm in standard length (SL), market at Hepu (Nanliujiang River basin), near Beihai City, Guangxi, China (21°42' N, 106°48' E), 16 November 1999, collected by C.-G. Zhang. Paratypes. IOZCAS 69848 (1 specimen), 142.1mm SL; IOZCAS 69849 (1), 159.3 mm SL (dissected for observation of suprabranchial organ); IOZCAS 70029 (1), 178.9mm SL; IOZCAS 70030 (1), 197.6mm SL; IOZCAS 70039 (1), 178.3mm SL (dissected for observation of suprabranchial organ); IOZCAS 70042 (1), 185.7mm SL, data as for the holotype, except IOZCAS 69848 and 69849, collected by K. Watanabe and C-G. Zhang on 26 April 1999. Diagnosis. A species of Channa distinguishable from all other channid species by the following combination of Ichthyological Research ©The Ichthyological Society of Japan 2002 Ichthyol Res (2002) 49: 140–146 T he snakeheads or fishes of the family Channidae are widely distributed in South, Southeast, and East Asia and in the west central part of Africa (Nelson, 1994). Channids are more diverse in Asia, 23 species, all included in the genus Channa Scopoli (see Musikasinthorn, 2000; Musikasinthorn and Taki, 2001), currently being considered as valid. From Africa, only 3 species are recognized, all being included in the genus Parachanna Teugels and Daget (see Bonou and Teugels, 1985; Teugels, 1992). Interestingly, some Asian channid species entirely lack pelvic fins. From a field survey conducted by the first and third au- thors in Guangxi Province, China, in April and November, 1999, specimens of a darkish colored, pelvic fin-less chan- nid species, which superficially resembled C. asiatica (Linnaeus), were collected. Upon subsequent examination, the specimens were found to represent an undescribed spe- cies, described herein as new. Methods Methods for counts, measurements, and nomenclature of the suprabranchial organ followed Musikasinthorn (1998). Fin rays were counted with a binocular microscope or taken