cnidarian

Definitions of cnidarian

1. noun

   radially symmetrical animals having saclike bodies with only one opening and tentacles with stinging structures; they occur in polyp and medusa forms
   synonyms: coelenterate

   types:

   polyp

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

   medusa, medusan, medusoid

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

   jellyfish

   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

   planula

   the flat ciliated free-swimming larva of hydrozoan coelenterates

   Aegina

   small medusa

   Chrysaora quinquecirrha

   a type of jellyfish

   hydra

   small tubular solitary freshwater hydrozoan polyp

   siphonophore

   a floating or swimming oceanic colony of polyps often transparent or showily colored

   sertularian

   feathery colony of long-branched stems bearing stalkless paired polyps

   anemone, sea anemone

   marine polyps that resemble flowers but have oral rings of tentacles; differ from corals in forming no hard skeleton

   sea pen

   fleshy featherlike warm-water colonies

   coral

   marine colonial polyp characterized by a calcareous skeleton; masses in a variety of shapes often forming reefs

   type of:

   invertebrate

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