Studies on the epidermis of Temnocephala I. Ultrastructure of teh epidermis of Temnocephala novae-zealandiae

Abstract

The epidermis of T. novae-zealandiae is syncytial, unciliated and fringed with microvillus-like projections. It does not secrete an inert cuticle. The clear border ('cuticle') observed by light microscopy is revealed at ultrastructural resolution to be a surface layer of accumulated secretion bodies, which originate in golgi systems at deeper levels within the epidermis. The epidermis displays a high degree of regional differentiation. The peripheral layer of secretion bodies is lacking at the ventral surface of the attachment disc. The dorsal epidermis is deeply pitted by closely spaced, cylindrical depressions, and appears to be especially active in the synthesis of secretion. The minute terminal branches of the ducts of mesenchyme glands show a clear-cut regional distribution. The clear border of the temnocephalid epidermis is not comparable with the cuticle of trematodes.