Multiciliate sensory endings in the redia of Echinostoma revolutum (Trematoda, Echinostomatidae).

In addition to uniciliate sensory endings, three types of multiciliate sensory endings have been demonstrated on the anterior end of Echinostoma revolutum redia using transmission and scanning electron microscopy. This is the first finding of multiciliate sensory endings in the parthenogenetic generation of trematodes. In the first type, 12 cilia are situated in a pit communicating with the tegument surface. In the second and third types, there are two and four short cilia, respectively. They protrude from the nerve bulb above the surface of the tegument. The significance of multiciliate sensory endings in rediae and their similarity to multiciliate sensory endings in miracidia and cercariae is discussed.