Plerocerci of Callitetrarhynchus gracilis in the body cavity of the fish Scomberomorus commerson<unk>  refers to last larval form, the infective form, found in the second intermediate host of many Cestoda with aquatic life cycles.
Plerocercoid
Cysticercoid
Hookworm
Schistocyte
Spirometra
Amoeba
Pinworm 
Culion leper colony