Transmission electron microscopy of sensory receptors of Echinostoma revolutum (Froelich 1802) cercaria (Digenea: Echinostomatidae).

Nonciliate, uniciliate, and multiciliate receptors were shown by transmission electron microscopy to occur in the body tegument of Echinostoma revolutum (Froelich 1802) cercariae. Detailed studies revealed three types of nonciliate, four types of uniciliate, and one type of multiciliate sensory endings. Most receptors were singly distributed. Only a few of them formed paired receptor complexes in three regions of the cercarial body. These receptor complexes were found to possess nonciliate, uniciliate, and multiciliate sensory endings.