Morphology and Some Histochemical Peculiarities of the Mucous Glands in the Integument of the Green Toads of Bufo viridis Complex (Amphibia: Bufonidae)

We described three groups (varieties) of the mucous glands in the skin of the green toads of Bufo viridis complex basing on the morphology and histochemistry [mucopolycaccharide (MPS) composition] of their secretory epithelium and a localization of the glands in the toad integument. Our study showed that the mucous cells of three gland groups were differed in their morphology and content of the acid and neutral MPS. Only the ordinary mucous glands (group I) were found within the entire integument and only the skin of parotoid complexes contained the mucous glands of all three varieties. We consider the glands of group III as structures of full secretory maturity. Morphological and histochemical features of the glands of II (and possibly III) varieties as well as their selective distribution in the integument of the green toads permit to suppose their specific functions which need to be elucidate.