Trematode -

: A tough, continuous outer layer called a syncytial tegument protects them from the host's digestive enzymes and immune system.

Schistosomes and Other Trematodes - Medical Microbiology - NCBI trematode

, 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 : A tough, continuous outer layer called a

: 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. Complex Life Cycle : They typically have flattened,

: 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

: They typically have flattened, leaf-like, or worm-like bodies ranging from 1 mm to several centimeters in length.