The fine structure of the cuticle and interchordal hypodermis of the parasitic nematodes, Capillaria hepatica and Trichuris myocastoris.

Abstract

The cuticle and underlying hypodermis of the parasitic nematodes, Capillaria hepatica and Trichuris myocastoris, were examined by light and electron microscopy. The cuticle in both species consists of a filamentous, collagenous, basal layer, which contains a zone of striated material in its outer region; a matrix layer; and thin cortical layers which may appear as three osmiophilic lines. It is suggested that the striated layer of the cuticle provides the tensile strength given by fiber layers in the cuticle of other species. The matrix layer of T. myocastoris contains large amounts of non-glycogen polysaccharide while the matrix layer of C. hepatica does not. It is speculated that the polysaccharide content of the cuticle may determine its permeability characteristics. The interchordal hypodermis contains little endoplasmic reticulum, very few Golgi zones, but abundant mitochondria. In C. hepatica the interchordal hypodermis is formed of cell processes from cells of the lateral and median hypodermal chords, while in T. myocastoris, it is cellular.