Morphology

	Echinostomes are characterized by a collar of spines (papillae) around their anterior ends. Depending on the species, this hermaphroditic flatworm can grow from 3-25 mm in length and 1-3 mm in width (Graczyk and Fried, 1998). The oral sucker and large ventral sucker enable the trematode to attach to the human intestinal wall.
(Photograph by S.J. Upton)

(P.W. Pappas and S.M. Wardrop)