Body Wall Musculature of Five Representatives of the Order Paramphistomatida (Plathelminthes, Trematoda)

Abstract

The morphology of the body wall is described for five trematode species belonging to four families of the order Paramphistomatida. In all the species under study, the thickness of the outer plate of the tegument is minimal in the sucker cavities and is constant in other areas of the integument, the number and sequence of the muscle layers (circular, longitudinal, and diagonal) coincide. The layers consist either of individual muscle fibers or of muscle bundles. The longitudinal parenchimal muscles, topographically close to the integument, can be mistakenly assigned as the peripheral musculature. The thickness and sparseness of the circular and longitudinal layers vary considerably in different parts of the integument. Diagonal muscles are characterized by an oblique angle of intersection, high regularity of location, and slight changes in thickness.