jellyfish(redirected from Scyphomedusae)
Also found in: Dictionary, Thesaurus, Encyclopedia, Wikipedia.
Marine coelenterates (class Hydrozoa) including some poisonous species, notably Physalia, the Portuguese man-of-war; toxin is injected into the skin by nematocysts on the tentacles, causing linear wheals.
Synonym(s): jelly (2)
n. pl. jellyfish or jelly·fishes
a. Any of numerous usually free-swimming marine cnidarians of the class Scyphozoa, characteristically having a gelatinous, tentacled, often bell-shaped medusa stage as the dominant phase of its life cycle. Also called true jellyfish.
b. Any of various similar or related cnidarians.
Marine coelenterates, including some poisonous species; toxin is injected into the skin by nematocysts on the tentacles, causing linear wheals.
- any large medusa of the class Scyphozoa.
- the medusoid stages of any coelenterate.
members of the class of aquatic animals the Scyphozoa, the true jellyfishes, in the phylum Cnidaria. All possess cnidia or stings and are capable of causing stings to animals.