The manca (plural: mancae) is the post-larval juvenile in some crustaceans. The manca stage is the defining characteristic of a clade called Mancoida which comprises all the member of the Peracarida except the Amphipoda.[1] Mancae closely resemble the adult form, but for the absence of the last pair of pereiopods.[1] In some isopods, specifically the family Gnathiidae, the manca stage is a parasite of fish, and is also known as the praniza.[2]