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THE FLATWORMS— PLATYHELMINTHES 



of some water animals. The life cycles of flukes often include one or 

 more hosts in addition to the one which is infested during the adult 

 stage. Quite often the snail is one of the alternate hosts which serves 

 to harbor the larval stages of these parasites. 



A good example of this class is the Chinese liver fluke, Chlonorchis 

 (O pisthorchis) sinensis, which is found in large numbers of people in 

 China, Japan, and Korea because of their living and eating habits. These 



eating raw fish 



Animals Without Backbones, Buchsbaum, The University of Chicago Press 

 Fig. 10.8. Diagram illustrating the life cycle of the Chinese liver fluke. 



adult flukes live in the liver and sometimes cause a partial breakdown 

 of that organ called liver rot. Also, a type of jaundice may result from 

 the clogging of the passageways for the bile. The animals are herma- 

 phroditic like the planaria and, after fertilization, the eggs are released 

 and make their way down the bile duct, into the intestine, and eventually 

 out of the body along with the indigestible food or feces. The eggs 

 must reach water in a short time in order to continue the cycle. This 



