Rhizostoman.
/ˌrʌɪzəˈstəʊmə/, /rʌɪˈzɒstəmə/, U.S. /ˌraɪzəˈstoʊmə/, /ˌraɪˈzɑstəmə/ Zoology.
A genus of scyphozoan jellyfishes that is the typical genus of the order Rhizostomeae (see rhizostome n.); (also rhizostoma) a jellyfish of this genus or (formerly also) order.
ΚΠ
1809 W. Nicholson Brit. Encycl. II. at Compar. anat. Cuvier has formed a new genus, under an appellation derived from this comparison, viz. the rhizostoma.
1809 Philos. Mag. 34 309 M. Peron on the contrary, having observed several living rhizostoma.., is of opinion, that these are four distinct mouths and stomachs.
1841 Penny Cycl. XIX. 119/2 Certain Rhizostomata acquire a considerable development, so as to reach nearly a foot and a half in diameter.
a1933 J. A. Thomson Biol. for Everyman (1934) I. v. 94 A hundred horse-mackerels may shelter under the jellyfish Rhizostoma, which does them no harm.
1972 Trans. Amer. Microsc. Soc. 91 215 Atrichs and euryteles only are present in the semaeostome Aurelia and the rhizostomes Cotylorhiza and Rhizostoma.
1993 Jrnl. Marine Biol. Assoc. 73 15 The high concentration of sulphate in the gastrovascular fluid of medusae has been confirmed by rhodizonate titration in Cyanea and Rhizostoma jellyfish.
2006 Ecology 87 1968/2 The Solway Firth [was] identified as a fourth area where Rhizostoma occurred in significant numbers.
Derivatives
rhizoˈstomatous adj. belonging to the genus Rhizostoma or order Rhizostomeae.
ΚΠ
1838 T. R. Jones in Todd's Cycl. Anat. & Physiol. II. 409/2 The young..in the Rhizostomatous species [are excluded] through the ramified canals of the pedicle.
1892 Science 1 Jan. 10/2 Mr. Field found..a very remarkable rhizostomatous medusa belonging to the genus Cassiopea.
1955 AIBS Bull. 5 30/2 Winds frequently bring the Portuguese Man-of-War, the rhizostomatous medusa..and siphonophores of more southern waters close to shore in large numbers.
1994 Jrnl. Crustacean Biol. 14 782/1 The bottom-dwelling rhizostomatous scyphozoan Cassiopeia..is the host.
rhiˈzostomous adj. now rare = rhizostomatous adj.
ΚΠ
1858 R. G. Mayne Expos. Lexicon Med. Sci. (1860) 1094/1 Rhizostomus,..rhizostomous.
1885 Jrnl. Royal Microsc. Soc. 5 72 The family of the Versuridæ, comprising large rhizostomous Medusæ, is comparatively rare in the northern hemisphere.
1926 Science 17 Dec. 600/2 A two and five tenths foot specimen..had in its stomach a large number of the beaks of small cephalopods and also remains of rhizostomous jellyfishes.
This entry has been updated (OED Third Edition, June 2010; most recently modified version published online June 2022).
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