Annelides parasitic

Intracellular parasites in the young stages only in the adult stage of the life cycle parasitic in invertebrates, mostly in the digestive tract of arthropods and annelids, young stage in the epithelial cells of this tract. 

Helminths are worm-like organisms of which several classes of parasites are found including nematodes (roundworms), cestodes (tapeworms), and trematodes (flukes). Leeches, of the phylum Annelid, are also... 

Hirudinea A class of freshwater and terrestrial annelid worms that comprises the leeches. They have suckers at both anterior and posterior ends but no bristles. Some are blood- sucking parasites of vertebrates and invertebrates but the majority are predators. 

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