Fine structure of epidermal mucous cells of some Brazilian earthworms (Oligochaeta:Annelida).

Electron microscopic techniques were adopted to study the comparative morphology of the secretory granules of the epidermal mucous cells of 4 species of brazilian earthworms. 2 main types of secretory granules were described: A first type, presenting a central body with a high electron density and surrounded by a material with variable aspects and electron densities. The second type of secretory granule possesses an homogeneous aspect and a relatively low electron density. The size and the morphology of secretory granules reveal significant variations among the species and also inside a single specie.