Polymorphism and Geographic Distribution of Skin Texture of Six Species Amphibians in Hengduan Mountains

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,Kangding,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.