There are more than one type of fluke in its class and it deals with almost everything we can think of.
Fluke, also called blood fluke or trematode,is any member of the invertebrate class Trematoda (phylum Platyhelminthes), a group of parasitic flatworms that probably evolved from free-living forms millions of years ago. There are more than 10,000 species of flukes. They occur worldwide and range in size from about 5 millimeters (0.2 inch) to several centimeters; most do not exceed 100 millimeters (4 inches) in length.