Coronamedusae is a subclass of

jellyfish Jellyfish and sea jellies are the informal common names given to the medusa-phase of certain gelatinous members of the subphylum Medusozoa, a major part of the phylum Cnidaria. Jellyfish are mainly free-swimming marine animals with umbrella- ...

in the class

Scyphozoa The Scyphozoa are an exclusively marine class of the phylum Cnidaria, referred to as the true jellyfish (or "true jellies"). The class name Scyphozoa comes from the Greek word ''skyphos'' (), denoting a kind of drinking cup and alluding to the ...

. It is the sister

taxon In biology, a taxon (back-formation from ''taxonomy''; plural taxa) is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit. Although neither is required, a taxon is usually known by a particular nam ...

Discomedusae Discomedusae is a subclass of jellyfish in the class Scyphozoa. It is the sister taxon of Coronamedusae. Discomedusae contains about 155 named species and there are likely to be many more as yet undescribed. Jellyfish in this subclass are much ...

and contains about 50 named species, all included in the order Coronatae. Jellyfish in this subclass are either small

medusae Jellyfish and sea jellies are the informal common names given to the medusa-phase of certain gelatinous members of the subphylum Medusozoa, a major part of the phylum Cnidaria. Jellyfish are mainly free-swimming marine animals with umbrella- ...

living in shallow marine environments, or large medusae living in the deep sea. The mouthparts of the members of this subclass are characterised by simple lips on a short

manubrium The sternum or breastbone is a long flat bone located in the central part of the chest. It connects to the ribs via cartilage and forms the front of the rib cage, thus helping to protect the heart, lungs, and major blood vessels from injury. Sha ...

as well as by robust marginal tentacles that arc away from the mouth. It is likely that these marginal tentacles are used to capture

plankton Plankton are the diverse collection of organisms found in Hydrosphere, water (or atmosphere, air) that are unable to propel themselves against a Ocean current, current (or wind). The individual organisms constituting plankton are called plankt ...

, including

crustacea Crustaceans (Crustacea, ) form a large, diverse arthropod taxon which includes such animals as decapods, seed shrimp, branchiopods, fish lice, krill, remipedes, isopods, barnacles, copepods, amphipods and mantis shrimp. The crustacean gro ...

ns and small

fish Fish are aquatic, craniate, gill-bearing animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish as well as various extinct related groups. Approximately 95% of li ...

in the larger species.

Coronatae

Coronatae is the only order in this subclass, with around thirty-five species having been described, most of them deepwater jellyfish. The

thimble jellyfish The thimble jellyfish (''Linuche unguiculata'') is a species of cnidarian found in the warm West Atlantic Ocean, including the Caribbean. It is a tiny jellyfish with a straight-sided, flat-topped bell. This jellyfish is the most common cause of ...

(''Linuche unguiculata'') is a tiny species, and one of the few from shallow tropical seas; It is a

zooxanthellate Zooxanthellae is a colloquial term for single-celled dinoflagellates that are able to live in symbiosis with diverse marine invertebrates including demosponges, corals, jellyfish, and nudibranchs. Most known zooxanthellae are in the genus ''Symbi ...

species. Coronatids have a characteristic constriction, the coronal groove, part way down the bell. Below this the bell is creased and lobed into four pedalia. Each pedalium bears a small non-retractible tentacle, and the margin of the bell bears either four or eight rhopalia (sensory organs) in the niches between flaps known as lappets. The coronal groove and the creases provide flexibility in the otherwise rather stiff bell. The short manubrium is four-sided and has a large mouth at its tip. The mouth opens into a central stomach which is divided into four pockets by septa, on which are located the gastric filaments and the eight gonads. Most coronatids search for prey with outstretched tentacles; when food items are found, they are subdued and pushed rather stiffly into the mouth by the tentacles.

Taxonomy

According to the

World Register of Marine Species The World Register of Marine Species (WoRMS) is a taxonomic database that aims to provide an authoritative and comprehensive list of names of marine organisms. Content The content of the registry is edited and maintained by scientific specialist ...

, Coronamedusae contains the following taxa: * Order

Coronatae Crown jellyfishes are the six families of true jellyfish that belong to the order Coronatae.Daly, Brugler, Cartwright, Collins, Dawson, Fautin, France, McFadden, Opresko, Rodriguez, Romano & Stake (2007). The phylum Cnidaria: A review of phylog ...

** Family

Atollidae ''Atolla'' is a genus of crown jellyfish in the order Coronatae. The genus ''Atolla'' was originally proposed by Haeckel in 1880 and elevated to the monotypic family level, as Atollidae by Henry Bigelow in 1913. The six known species inhabit t ...

Bigelow, 1913 ** Family

Atorellidae ''Atorella'' is a genus of crown jellyfish. It is the only genus in the monotypic family Atorellidae and includes five species. Members of this family are known from the eastern coast of Africa and the western coast of Panama. Characteristics Me ...

Vanhöffen, 1902 ** Family

incertae sedis ** Family

Linuchidae Linuchidae is a family of crown jellyfish. Species *''Linuche ''Linuche'' is a genus of cnidarians belonging to the family Linuchidae. The species of this genus are found in America and Southeastern Asia. Species: *''Liniscus cyamopterus'' ...

Haeckel, 1880 ** Family

Nausithoidae Nausithoidae is a family of jellyfish. Genera *''Nausithoe'' ** '' Nausithoe albatrossi'' (Maas, 1897) ** '' Nausithoe atlantica'' (Broch, 1914) ** ''Nausithoe aurea'' Da Silveira & Morandini, 1997 ** '' Nausithoe challengeri'' (Haeckel, 1880) * ...

(Claus, 1883) ** Family Paraphyllinidae Maas, 1903 ** Family

Periphyllidae Periphyllidae is a family of jellyfish containing four genera and six species. The most well-known member of the family, ''Periphylla periphylla'', is usually considered a deep-sea The deep sea is broadly defined as the ocean depth where light ...

Haeckel, 1880

References

Scyphozoa {{Scyphozoa-stub