The characteristic larva of phylum'Coelenterata' is

Coelenterata (coelom + enteron) or phylum Cnidaria shows both sexual and asexual reproduction. The larval stages areplanula (Obelia) andephyra (Aurelia).Cysticercus (bladder worm) is the third larval stage seen in Taenia besides oncosphere, hexacanth (other two larval stages). Cysticercus is seen after the hexacanth released in the stomach of pig, which, goes through blood circulation and on reaching muscles get encysted in the form of bladderworm.Rhabditiform is the first larval stage in Ascaris which is formed within $10-14$ days. It is non-infective juvenile stage which rests for a week and completes first moult within egg and becomes second stage rhabditiform larva which is infective. The larva is called rhabditiform or rhabditoid because of its close resemblance with Rhabditis.Wriggler is the larva of mosquito. It is free-swimming, active, aquatic larva performing wriggling movements. It has a life-span of 3-4 days.