Leech
Leeches are segmented parasitic or predatory worms that belong to the phylum Annelida. They are closely related to the oligochaetes, which include the earthworm, and like them have soft, muscular, segmented bodies that can lengthen and contract. The majority of leeches live in freshwater habitats, while some species can be found in terrestrial or marine environments. Leeches have been used...