Liver fluke. Light micrograph (LM) of the liver fluke Clonorchis sinensis, which infects millions of people in the Far East. The fluke's digestive system is the pair of faint intestinal tubes running from the oral sucker (left) down the length of its body (purple). The hermaphroditic worm's branched testes (pale blue) are at far right, while its uterus is made up of the dark green sausage-shapes at centre, inside the grainy yolk-forming (vitelline) glands. C. sinensis has two secondary hosts: freshwater snails and fish of the minnow and carp family. Humans are infected by eating raw fish, resulting in diarrhoea, abdominal pain and liver cirrhosis. Magnification: x50 at 10cm wide.