ULTRASTRUCTURE OF THE URINARY BLADDER OF SALAMANDRA SALAMANDRA (L.) (AMPHIBIA CAUDATA)

Abstract

SUMMARY The mucosa of the urinary bladder of Salamandra salamandra (L.) (Amphibia Caudata) was studied by electron microscopy. Its epithelium basically consists of three cell types: (i) «granular cells» which are flattened and characterized by a layer of granules of mucous secretion, by abundant filamentous material and by occasionally anomalous mitochondria, while their free surface shows many microvilli and a distinct fuzzy coat; (ii) «mitochondria-rich cells», with a typical flask shape and abundance of mitochondria; (iii) rare basal cells. The epithelial cells are connected by typical junctions, adjacent membranes exhibiting deep infoldings. Thus in the urinary bladder of an urodele amphibian, as previously observed in anuran amphibians, it has been possible to demonstrate the presence of structural devices which can be related to water and ion resorption.