, commonly known as flukes , are a class of parasitic flatworms within the phylum Platyhelminthes. There are an estimated 18,000 to 24,000 species, most of which are obligate internal parasites that inhabit the blood, liver, lungs, or intestines of vertebrate hosts. Biological Characteristics
: They possess two muscular suckers—an oral sucker near the mouth and a ventral sucker (acetabulum) on the underside—to anchor themselves to host tissues. trematode
: Most are hermaphroditic (monoecious), containing both male and female reproductive systems and capable of self-fertilization. A notable exception is the Schistosoma genus, which has separate male and female sexes. Complex Life Cycle , commonly known as flukes , are a
Schistosomes and Other Trematodes - Medical Microbiology - NCBI : Most are hermaphroditic (monoecious), containing both male
Trematodes typically require at least two different hosts to complete their development:
: A tough, continuous outer layer called a syncytial tegument protects them from the host's digestive enzymes and immune system.
: They typically have flattened, leaf-like, or worm-like bodies ranging from 1 mm to several centimeters in length.