Organization of the Epidermal Syncytial Mosaic in Diceratocephala-Boschmai (Temnocephalida, Platyhelminthes)

Abstract

The epidermis of Diceratocephala boschmai Baer, 1952 (Temnocephalida : Platyhelminthes) was studied using silver-nitrate staining and electron microscopy. The epidermis consists of six syncytia separated by lateral membranes: the frontal, trunk, stalk, adhesive disc syncytia, and a pair of post-tentacular syncytia. Neighbouring syncytia differ in many characters including (1) the presence or absence of locomotory cilia, (2) the degree of the differentiation of the apical cytoplasm layer, (3) the presence or absence of bundles of cytoskeletal filaments, imaginations of basal membrane and other specialised cytoplasmatic structures, (4) the abundance of hemidesmosomes at the basal membrane, and (5) the abundance and nature of gland ducts penetrating the syncytium. These structural differences reflect functional differences between the syncytia. Thus, multisyncytial organisation of the epidermis may be explained by functional differences between the syncytia. Only between the frontal and trunk syncytia has no apparent ultrastructural difference been found.