Histological Observation of Skin in Four Species in the Genus Scutiger

We used the microscope to observe the dorsal and ventral skin of Scutiger(Scutiger)boulengeri,S.(Aelurophryne)mammatus,S.(A.)muliensis,and S.(A.)glandulatus in the genus Scutiger.The skins of the four species at different positions on the body,which including the epidermis and dermis,were different in thickness but similar in structure.Epidermis of the dorsal skin was thinner than that of the ventral skin,and had less cell layers,but overall,the dorsal skin was thicker than the ventral skin.Capillaries were distributed in the junction between the epidermis and dermis,parallel to the epidermis.Species of subgenus Aelurophryne had more capillaries,their skin played an important role in respiration.Dermis was made up of stratum spongiosum and stratum compactum.The stratum spongiosum was loaded with glands,which included two types:the mucus gland and granular gland.Mucus glands were widely distributed in different parts of the skin,and the granular glands were mostly distributed in the dorsal skin.The pigment layer was found on the top of dermis and was irregular in shape.The pigment layer was well-developed both in the dorsal and ventral skin,only slightly thinner in ventral skin.As Scutiger lived in the environment with low temperature,high altitude and strong ultraviolet radiation,the pigment layer played an important role in ecological adaptation.A special substance,the lamina calcare,had been discovered in both the dorsal and ventral corium tectorium in the four species.It showed as blue bands when HE staining was employed.There were no cell structures in the lamina calcarea which lay under the pigment layers.