摘要
钝头蛇亚科Pareinae隶属游蛇科Colubridae分布于10°S—35°N,80°—125°E的东南亚及其邻近岛屿,是具有吻钝,无颏沟和上颌骨前端无齿等特殊性状的唯一类群,原记载共2属16种。经全面分类清理后,该类群共有18种,分别隶属Pareas Wagler,Aplopeltura Dumeril et Bibron和Internatus gen.nov.三属,其中Pareas具派生性状最少为最原始,Aplopeltura具派生性状最多为最特化。Aplopeltura和Internatus可能分别源自Pareas的某一级或不同级的祖先,可能是第四纪大冰期时先后从大陆迁入马来半岛、苏门答腊、婆罗洲、爪哇和菲律宾南部,然后在间冰期和冰后期因适应岛屿环境而特化成的新类群。
Pareinae of colubridae is distributed in southeastern Asia and adjacent island from 10°S-35°N and 80°-125°E. It is the only group that has blunt snout, no mental groove and no teeth on the anterior part of maxillary. There were 2 genera and 16 species in the original references, namely Aplopeltura 1 species and Pareas 15 species. But in this research, we found that P. kuangtungensis and P. yunnanensis, which had ever been considered as the synonyms of P. chinensis, were valid species for their characters of maxillary teeth, length of hemipenis, ect.; P. niger was the synonym of P. yunnanensis; P. komaii from Taiwan and P. iwasakii from the Liu-Kiu islands were also valid species.P. laevis and P. malaccanus, which are distributed mainly in the Greater Sunda Islands, should be seperated as a new genus Internatus since they have one pre-chinshield and only 2 pairs of chinshields and so on.So far we found 1 genus, and confirmed 2 genera and 18 valid species:( 1 ) A. boa; (2)I. laevis; ( 3 ) I. malaccanus;( 4 ) P. margaritophorus; ( 5 ) P. macularius; ( 6 ) P. carinatus;(7) P.nuchalis; (8 ) P. monticola; ( 9 ) P. vertebralis;(10) P. boulengeri; (11) P. stanleyi; (12) P. chinensis;(13) P. formosensis; (14) P. hamptoni; (15) P. kuangtungensis;(16) P. yunnanensis; (17) P.komaii; (18) P. iwasakii.In order to study the relationships of the genera of Pareinae, 11 characters were selected with circumspection, and the out-group analysis and cladogram were adapted. The results are as follows (fig. 6):(1) Pareas, Internatus and Aplopeltura all showed the derived states of character 1, 2, 3 and 4. It indicates that they have a common origin, and Pareinae is a typically monophyly group;(2) Pareas and Internatus have the derived sfate of C.5, the relationship of them is closer. They probably have a common ancester, and it has an earlier ancester with Aplopeltura.(3) Pareas has only 6 derived states all together, while Internatus and Aplopeltura respectively have 7 and 8 derived states, so Pareas is primitive, Aplopeltura is more derived than Internatus, The common derived states of Internatus and Aplopeltura are fewer than those between each of them and Pareas, so the relationship of them is far. Since Pareas is primitive, Internatus and Aplopeltura probably originated respectively from the ancester of it during different times and derived in different direction.(4) The distribution of the 3 genera reflects their relationships: Pareas is distributed main- ly in the mainland, it is primitive; Internatus is near to the mainland and closer to Pareas than Aplopeltura in evolution; Aplopeliura is far away from the mainland, which is the most derived among 3 genera. Furthermore, it indicates that Internatus and Aplopeliura are respectively seperated from ancesters of Pareas in different times of geology.Internatus and Aplopeliura which are distributed mainly in the islands are more derived than Pareas which is chiefly in mainland as Fig.4 shows. According to the comparisons of other genera and species that are distributed in the islands, we also see that the genera, like the sub-famlies and families that distribute in the islands, are the same as those in the mainland (here including Malaya), although the species which are distributed in the islands are much different from those in the mainland; also the species in the different islands of the Greater Sunda are the same, they are fewer in quantity and more derived in morphology; and show the step-distribution that the quantity of species in the islands become decreased gradually with the island more and more distantly separated from the mainland. This means that the island-groups were migrated from the mainland not far long ago in the geology age.The Ice-Ages of Quaternary were probablely the causes and conditions of migration of the species from the mainland to the islands. The cold climates in the northern area and highlands and the relativly warm weather in the south was one aspact of the causes; meanwhile, the decrease of sealevel was the most important. During the ice-ages, the islands
出处
《动物学报》
SCIE
CAS
CSCD
1992年第2期139-150,共12页
ACTA ZOOLOGICA SINICA
关键词
钝头蛇亚科
谱系发育
地质演变
Pareinae, Phylogenetic Systenatics, Geology Changes.
