Crown jellyfishes are the six families of

true jellyfish 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 ...

that belong to the

order Order, ORDER or Orders may refer to: * Categorization, the process in which ideas and objects are recognized, differentiated, and understood * Heterarchy, a system of organization wherein the elements have the potential to be ranked a number of d ...

Coronatae.Daly, Brugler, Cartwright, Collins, Dawson, Fautin, France, McFadden, Opresko, Rodriguez, Romano & Stake (2007).
The phylum Cnidaria: A review of phylogenetic patterns and diversity 300 years after Linnaeus.
' Zootaxa 1668: 127–182 They are distinguished from other jellyfish by the presence of a deep groove running around the umbrella, giving them the

crown A crown is a traditional form of head adornment, or hat, worn by monarchs as a symbol of their power and dignity. A crown is often, by extension, a symbol of the monarch's government or items endorsed by it. The word itself is used, partic ...

shape from which they take their name. Many of the species in the order inhabit deep sea environments. Crown jellyfish are able to make light through

bioluminescence Bioluminescence is the production and emission of light by living organisms. It is a form of chemiluminescence. Bioluminescence occurs widely in marine vertebrates and invertebrates, as well as in some fungi, microorganisms including some ...

. When they are touched, their bells will light up. Otherwise, the bell of a crown jellyfish will look transparent when undisturbed. When they are attacked, crown jellyfish are able to startle, mislead, and distract their predators with the light that they produce. They may also use their bioluminescence to lure or dazzle their prey.

Families

, 53 recognized

extant Extant is the opposite of the word extinct. It may refer to: * Extant hereditary titles * Extant literature, surviving literature, such as ''Beowulf'', the oldest extant manuscript written in English * Extant taxon, a taxon which is not extinct, ...

species were in the order Coronatae, spread throughout 12 genera. These belong in the following six families: *

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)— one genus, seven species *

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)— one genus, five species *

Coronatae incertae sedis 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 phyloge ...

— one genus, four species *

Linuchidae Linuchidae is a family of crown 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 mainl ...

( Haeckel, 1880)— two genera, three species * Nausithoidae (Claus, 1883)— three genera, 26 species * Paraphyllinidae (Mass, 1903)— one genus, three species *

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)— four genera, six species Image:Atolla wyvillei (Operation Deep Scope 2004).jpg, ''

Atolla wyvillei ''Atolla wyvillei'', also known as the Atolla jellyfish or Coronate medusa, is a species of deep-sea crown jellyfish (Scyphozoa: Coronatae). It lives in oceans around the world. Like many species of mid-water animals, it is deep red in color. Thi ...

'' Image:Medusae of world-vol03 fig352-353 Nausithoë punctata.jpg, '' Nausithoe punctata'' Image:Haeckel Peromedusae.jpg, ''

Periphylla periphylla The helmet jellyfish (''Periphylla periphylla'') is a luminescent, red-colored jellyfish of the deep sea, belonging to the order Coronatae of the phylum Cnidaria. It is the only species in the monotypic genus ''Periphylla'' and is one of the rare ...

References

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