后棱蛇属Opisthotropis(蛇亚目:游蛇科:水游蛇亚科)一新种
摘要
A new species of natricine snake of the Southeast Asian genus <em>Opisthotropis</em> Gü nther, 1872 is described from western Hunan Province of China based on both mitochondrial DNA and morphological data. The new species is morphologically most similar and genetically most closely related to <em>O. cheni</em> Zhao, 1999 and <em>O. latouchii</em> (Boulenger, 1899), but possesses considerable genetic divergence (p-distance 5.1%-16.7%) and can be differentiated from all other congeners by a combination of the following morphological characters: (1) body size large (total length 514-586 mm) and strongly built; (2) dorsal scale rows 17 throughout, feebly keeled anteriorly and moderately keeled posteriorly; (3) ventral scales 147-152, subcaudal scales 54-62; (4) preocular absent, loreal elongated and touching orbit; (5) supralabials 8-9, fifth and sixth entering obit; (6) anterior temporals short, length 1.74-2.04 times longer than width; (7) maxillary teeth subequal, 28-30; (8) dorsal surface of head with distinct irregular yellow stripes and markings edged with ochre; (9) body with clear black and yellow longitudinal streaks, partly fused to several lighter patches or thicker stripes anteriorly; and (10) venter pale yellow, with asymmetric blackish speckles along outer margin. We present an updated diagnostic key to all members of the genus <em>Opisthotropis</em>, and recommendations on the ecological study for the group are provided.