Xyrias

E, John, Chen, Wei-Li & Chen, Hong-Ming, 2009, Comments on the snake-eel genus Xyrias (Anguilliformes: Ophichthidae) with the description of a new species, Zootaxa 2289, pp. 61-67 : 62-63

Key to the species of Xyrias

1a. Head and trunk longer than tail; snout length more than twice in upper jaw; pectoral fin 5.9–6.5 in head length (HL); center of eye above or before middle of upper jaw; total vertebrae 126–160 ............................................................. 2

1b. Head and trunk shorter than tail; snout longer, about twice in upper jaw; pectoral fin longer, 3.6–6.1 in HL; center of eye behind middle of upper jaw; total vertebrae 194–199 ........................................................................ X. guineensis

2a. Body, head and tail covered with numerous small to medium brown spots; inner row of maxillary teeth in a broad patch; total vertebrae 140–160 ...................................................................................................................................... 3

2b. Body, head and tail without brown spotting; inner row of maxillary teeth uniserial; vertebral formula 19/61/126 ......

.................................................................................................................................................... X. chioui , new species 3a. Head 7.2–7.8 in total length (TL); pectoral fin 3.6–4.3 in HL; middle of orbit above middle of upper jaw; mean vertebral formula (MVF) 16.7/67.3/140.3; total vertebrae 140–141 ........................................................... X. multiserialis 3b. Head 9.1–9.6 in TL; pectoral fin 5.3–6.1 in HL; snout shorter, rear margin of orbit above middle of upper jaw; MVF 17.8/77.8/157.2; total vertebrae 155–160 ..................................................................................................... X. revulsus