Scyphozoa

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Scyphozoa

[‚sī·fə′zō·ə]
(invertebrate zoology)
A class of the phylum Cnidaria; all members are marine and are characterized by large, well-developed medusae and by small, fairly well-organized polyps.
McGraw-Hill Dictionary of Scientific & Technical Terms, 6E, Copyright © 2003 by The McGraw-Hill Companies, Inc.
The following article is from The Great Soviet Encyclopedia (1979). It might be outdated or ideologically biased.

Scyphozoa

 

a class of solitary marine animals of the phylum Coelenterata. Scyphozoans occur in the form of jellyfish or polyps and are radially symmetrical. The gastric cavity is divided by interradial mesenteries into a central cavity and lateral pouches. Many scyphomedusae have a system of digestive canals. The life cycle is characterized by alternating generations (metagenesis). A planula larva develops from an egg and, after settling on a substrate, becomes a scyphistoma, an individual of the polypoid generation. The scyphistoma buds off polyps like itself and releases ephyrae (larvae of the sexually reproducing generation) by constriction (strobilation).

Bodily contact with certain scyphozoans, for example, Rhizostomae, may cause pain and skin burns. Persons have been known to die after being poisoned by individuals of the genus Chirodrophus, which dwell off northern Australia. Some scyphozoans, for example, Rhizostomae and Aurelia, are commercially significant; they are salted and used as food.

The class of Scyphozoa, comprising the orders Discomedusae, Rhizostomae, Coronatae, and Stauromedusae, includes approximately 200 species, which are distributed throughout the oceans of the world, mostly in temperate and tropical waters. Approximately 30 species occur in the USSR.

REFERENCES

Naumov, D. V. Stsifoidnye meduzy morei SSSR. Moscow-Leningrad, 1961.
Bronns, H. G. Klassen und Ordnungen des Tierreichs, vol. 2, part 2, fascs. 1–6. Leipzig, 1936–59.
Kramp, P. L. Synopsis of the Medusae of the World. Cambridge, 1961.

D. V. NAUMOV

The Great Soviet Encyclopedia, 3rd Edition (1970-1979). © 2010 The Gale Group, Inc. All rights reserved.
References in periodicals archive ?
The new records of scyphozoan species from Argentine and Uruguayan continental shelves and their adjacent oceanic waters presented in this study exceeded by 3.4 times the total number of previously reported data collected for the same area during the last 137 years (1880 to 2017) and represents the largest scyphozoan data-base from Latin America in terms of the sampling effort (temporal and spatial coverage) and biological and ecological information.
Organic tubes of modern coronate scyphozoans exhibit similar properties to the described Byronia tubes.
Concentric rings, weakly disc-like shapes, radial structures (including radial cracks), a range of taphonomic grades (from well- to poorly preserved) and peripheral troughs are common features of fossil scyphozoan medusae (Schafer 1941, 1972; Muller 1984; Bruton 1991; Young and Hagadorn, 2010).
Cubozoan and scyphozoan jellyfishes of the Carolinian Biogeographic Province, southeastern USA.
The scyphozoan solution involves the use of such a diffuse, non-polarized nerve net for distribution of motor commands (Mayer, 1910; Bozler, 1926a, b; Horridge, 1956a).
Since the statolith of both scyphozoan and cubozoan rhopalia is not organized into a recognizable statocyst-like structure, it is possible that the statolith functions as a weight to maintain a specific rhopalial orientation independent of orientation of the medusa, as demonstrated by Garm et al.
Induction of metamorphosis in the symbiotic scyphozoan Cassiopea andromeda: a role of marine bacteria and of biochemicals.
They captured the hydrozoans using dactyls at the tip of their pereiopods immediately after contact with the jellyfish, a predatory behavior very similar to that seen with the scyphozoans. Interestingly, the phyllosomas had no problems in associating with and feeding on Portuguese man-of-war, Physalia physalis (Fig.
Nemopilema nomurai Kishinouye 1922 is one of the largest scyphozoan jellyfish, measuring 1-2 m in diameter and weighing 100-200 kg.
The giant jellyfish Nemopilema nomurai Kishinouye 1922 is one of the biggest scyphozoan jelly fishes in the world, attaining a bell diameter of 2 m and a wet weight of 200 kg (Kishinouye, 1922; Shimomura, 1959).
The morphological diversity of pelagic scyphozoan orders originated during the Cambrian (Willoughby and Robison, 1979; Hagadorn et al., 2002 Cartwright et al., 2007) and persisted through five mass extinctions that eradicated many more-diverse taxa.