coelenteron - the saclike body cavity of a coelenterate

invertebrate - any animal lacking a backbone or notochord; the term is not used as a scientific classification

Cnidaria, Coelenterata, phylum Cnidaria, phylum Coelenterata - hydras; polyps; jellyfishes; sea anemones; corals

polyp - one of two forms that coelenterates take e.g. a hydra or coral: usually sedentary and has a hollow cylindrical body usually with a ring of tentacles around the mouth

medusa - one of two forms that coelenterates take: is the free-swimming sexual stage in the life cycle of a coelenterate and has a gelatinous umbrella-shaped body and tentacles

medusan, jellyfish, medusa - any of numerous usually marine and free-swimming coelenterates that constitute the sexually reproductive forms of hydrozoans and scyphozoans

scyphozoan - any of various usually free-swimming marine coelenterates having a gelatinous medusoid stage as the dominant phase of its life cycle

hydroid, hydrozoan - colonial coelenterates having the polyp phase dominant

actinozoan, anthozoan - sessile marine coelenterates including solitary and colonial polyps; the medusoid phase is entirely suppressed