Clonorchis spp.

Clonorchis sinensis. Adult worm (carmine stain, scanning power). These adults live in the bile passages of humans and various animals, and usually measure 10 to 25 mm long. The ventral sucker is smaller than the oral sucker. Two highly branched testes lie one behind the other in the posterior portion of the worm. An ovary is anterior to the testes, and the coiled uterus fills the midportion of the body between the ovary and the ventral sucker. Vitelline glands lie along the lateral margins in the midportion of the fluke. There are no spines on the tegumental surface.