A study of the cuticle of Gordius robustus, a nematomorph worm. I. Cuticle in the parasitic phase.

1. An investigation on the structure and chemical nature of the cuticle of a nematomorph worm Gordius robustus and its role in the physiology of the endoparasitic phase has been conducted. 2. The cuticle has fundamentally three layers; the cortical, homogeneous and fibrillar layers, differing from one another in physical as well as chemical properties. 3. The cortical layer has organic sulphur and acid mucopolysaccharide; the homogeneous layer has organic sulphur together with collagen-like protein and the fibrillar layer has only collagen. 4. Electrophoretic and chromatographic analyses reveal the presence of four proteins with different amino acid composition; the carbohydrate components of the cuticle are galactose and mannose. 5. Alkaline phosphatase and non-specific esterase are found in the cuticle of the general body surface and these seem to be related to the cutaneous absorption of materials. 6. Using peroxidase as tracer protein, the absorption of materials across the cuticle from outside the body has been demonstrated; this absorption is found to be an active process.