": any of a phylum (Cnidaria) of radially symmetrical, aquatic, invertebrate animals that have a hollow digestive cavity opening to the outside by a single opening surrounded by one or more nematocyst -studded whorls of tentacles, that occur as single or colonial sessile, typically columnar polyps or usually free-swimming, bell-shaped medusae , and that include the corals, sea anemones, jellyfishes, hydras, and Portuguese man-of-wars":[
"Welcome to the world of cnidarians \u2014a family of sea anemones, jellyfish and other marine invertebrates that kill their enemies and prey by firing poisonous, microscopic projectiles called nematocysts.",
"\u2014 R. Weiss"
]
},
"pronounciation":[
"-\u0113-\u0259n",
"n\u012b-\u02c8der-\u0113-\u0259n"
],
"synonyms":[],
"antonyms":[],
"synonym_discussion":"",
"examples":[
"Recent Examples on the Web",
"If these typical cnidarians strike you as a bit bizarre, the myxozoans are even further out past the borders of the familiar. \u2014 John Timmer, Ars Technica , 26 Feb. 2020",
"In 1995, however, Mark Siddall, then at the Virginia Institute of Marine Science, and his colleagues argued that myxosporeans are weird members of the cnidarians , the group that includes jellyfish and corals. \u2014 Quanta Magazine , 19 Aug. 2019",
"The fork leading to cnidarians represents the final turnoff before animals become bilaterally symmetric, which makes them an interesting group to study because of the greater complexity that came with that later innovation. \u2014 Quanta Magazine , 8 Jan. 2019",
"To find out, the researchers decided to sequence the genome of Aurelia, the moon jellyfish, and then compare it to those of cnidarians without medusas. \u2014 Quanta Magazine , 8 Jan. 2019",
"That is in contradistinction to Cambrian fossils, among which are found representatives of all the main animal groups (annelids, arthropods, brachiopods, chordates, cnidarians , echinoderms, molluscs and so on) that are around today. \u2014 The Economist , 7 June 2018",
"The first saw the emergence of brachiopods and molluscs, the second that of annelids, cnidarians , echinoderms and chordates (a group that includes the vertebrates). \u2014 The Economist , 7 June 2018",
"Researchers initially thought these nematocysts might be genetically similar to those of cnidarians , animals such as jellyfish and sea anemones. \u2014 Rachel Brown, National Geographic , 5 Apr. 2017",
"In fact, the plankton\u2019s ballistic mechanisms are actually much more complex than those of cnidarians . \u2014 Rachel Brown, National Geographic , 5 Apr. 2017"
],
"history_and_etymology":{
"New Latin Cnidaria, phylum name (from Greek kn\u012b\u0301d\u0113 \"nettle, sea nettle\"\u2014of uncertain origin\u2014 + Latin -\u0101ria, neuter plural of -\u0101rius -ary entry 2 ) + -an entry 1":""
