中国蝮蛇头骨形态比较及分类学讨论 (蛇亚目:蝮亚科)

COMPARATIVE STUDIES ON THE SKULL MORPHOLOGY OF CHINESE SPECIES OF Agkistrodon AND Deinagkistrodon , WITH DISCUSSION ON THEIR CLASSIFICATION (Serpentes:Crotalinae)

目前,我国蝮蛇某些种类的分类仍存在不同见解,对蝮蛇类群的分类主要集中在外部形态的比较,而较少涉及内部结构的研究。因此,本文对我国13 个地区的8 种( 亚种) 共26 号蝮蛇的头骨进行了比较解剖。以头骨特征为依据,对岩栖蝮Agkistrodon saxatilis、乌苏里蝮A.ussurensis、蛇岛蝮A.shedaoensis、短尾蝮A.brevicaudus、秦岭蝮A.qinlingensis 等的有效性及分类地位进行了讨论;同时对尖吻蝮Deinagkistrodon acutus 的骨骼形态与其他种类也进行了比较,认为它们在谱系上应代表两个不同的类型,将它们分隶于蝮属Agkistrodon 和尖吻蝮属Deinagkistrodon 是合理的。还以头骨形态特征为依据对8 种蝮蛇编制了检索表。

The classification of some Chinese species of Agkistrodon and Deinagkistrodon remains controversial.As to now,the works mainly dealt with external morphological feathers and little involved internal characters.In this paper,a comparative study on skull morphology of 8 Chinese species (including subspecies) of Agkistrodon and Deinagkistrodon from 13 populations is performed,and the status and validity of some species are discussed.The results reveal:① brevicaudus is different from its congener blomhoffii in the following characters:the squamosal of blomhoffii doesn't extend beyond the posterior end of the braincase and pterygoid teeth extend beyond the junction with the ectopterygoid.So it supports the suggestion made by Zhao (1998) that brevicaudus ,which was treated as a subspecies of blomhoffii by many workers,should be placed at a species status and designated A.brevicaudus .② ussurisensis is separable from blomhoffii by the presence of weak parietal shield,broad and short lateral process of the fork of the ectopterygoid,pterygoid teeth not extending beyond the junction with ectopterygoid,squamosal extending beyond the posterior end of the braincase;from halys by the presence of postfrontal touches frontal,dorsal scale rows at midbody 21.These characters strengthen the idea that ussuriensis is a full species.③ saxatilis differs from intermedius in several characters,skull proportion of length to width,shape of parietal,the parietal shied and so on,so it is confirmed that saxatilis ,which was treated as a subspecies of intermedius by Gloyd et al .(1990),is a full species.④ shedaoensis is distinct from its congener saxatilis in characters of shape of squamosal,basisphenoid and basioccipital process,postfrontal;it is a valid species.⑤ A.halys qinlingensis Song can be separable from the relative species such as strauchii,halys and intermedius in the following characters:the shape of parietal,pterygoid teeth don't extend beyond the junction with ectopterygoid,squamosal extends beyond the posterior end of the braincase,parietal shield and dorsal scale rows at midbody.Thus raising A.h.qinlingensis as a full species is supported.Comparison studies on skulls among genera Agkistrodon and Deinagkistrodon are also completed. In the end of the paper,the key to these 8 species based on the skull characters was provided.