横断山区六种两栖类皮肤表型结构多态现象及其地理分布的探讨

POLYMORPHISM AND GEOGRAPHIC DISTRIBUTION OF SKIN TEXTURE OF SIX SPECIES AMPHIBIANS IN HENGDUAN MOUNTAINS

我国两栖类皮肤形态方面（非性征性状）的多态现象（ｐｏｌｙｍｏｒｐｈｉｓｍ）可分为两类，一类是色斑的，另一类是皮肤表型结构的。本文主要探讨后一类型“皮肤多瘰疣或满布瘰疣”的多态现象。目前在我国两栖类中已发现６种存在这种类型的多态性变体，其中有尾目２种Ｂａｔｒａｃｈｕｐｅｒｕｓｐｉｎｃｈｏｎｉｉ和Ｂ．ｔｉｂｅｔａｎｕｓ；无尾目４种Ｓｃｕｔｉｇｅｒ（Ｓｃｕｔｉｇｅｒ）ｂｏｕｌｅｎｇｅｉ，Ｓ．（Ａｅｌｕｒｏｐｈｒｙｎｅ）ｂｒｅｖｉｐｅｓ，Ｓ．（Ａ．）ｍａｍｍａｔｕｓ，Ｓ．（Ａ．）ｍｕｌｉｅｎｓｉｓ，它们主要分布于青藏高原东南部。根据以上有变体的６个种共计４３０７号标本的产地和数量说明，各个种的变体分布区甚为狭窄，其数量甚少，仅占各个种各地标本总数的０．３９％─６．６７％，但变体占同域标本数可达６．６７％─５１．９％。从四川康定县朋布西一地同域４种同时存在相同性状的变体分析，这些变体的产生可能与当地水域环境有关。

The polymorphism on skin morphology in amphibians may be divided into two types.One type is of the color morphs and the other type of the phenotypic texture of the skin.In the present paper the polymorphism of latter type is discussed.The skin texture of the variant individuals differs sharply from that of normal individuals by having skin very rough,crowed with warts,which is not correlated with the sex of the individuals.The polymorphic variants of the same texture are found at present in six species of amphibians in Hengduan mountains.Among them there are 2 species of urodeles(Batrachuperus pinchonii,and B.tibetanus) and 4 species of anurans[Scutiger(Scutiger) boulengeri,S.(Aelurophryne) brevipes,S.(A.) mammatus and S.(A.) muliensis].Based on 58 localities and number of polymorphic variants in 4307 individuals of abovesix species,it shows that the distribution ranges of appearing polymorphic variants are very narrow and frequencies very low.That account only for 0.39%-6.67% of total individuals of each species in every area,but 6.67%-51.90% in the same nich.The cause of this structural polymorphism may probably be closely related to habitat.Particularly, the variants of 4 species with the same special character exhibit simultaneously in the same mountain stream of Pengbuxi,Ka ngding,Sichuan.And the proportions of the polymorphic variants in these populations of the area are correlated with inhabitable time in the water environment.The frequencies of the variants in aquatic typic species are more than that of terrestrial species.Hence the fact that the very similar polymorphic variants of the skin crowded with warts exhibits in several species closely related or divergent of sympatry or allopatry show that the polymorphism may probably have direct relation to the water bodys of the streams of the areas.