Stauromedusae are the stalked jellyfishes. They are the sole living members of the

class Class or The Class may refer to: Common uses not otherwise categorized * Class (biology), a taxonomic rank * Class (knowledge representation), a collection of individuals or objects * Class (philosophy), an analytical concept used differentl ...

Staurozoa Staurozoa is a class of Medusozoa, jellyfishes and hydrozoans. It has one extant order: Stauromedusae (stalked jellyfishes) with a total of 50 known species. A fossil group called Conulariida has been proposed as a second order, although this is ...

and belong to the

medusozoa Medusozoa is a clade in the phylum Cnidaria, and is often considered a subphylum. It includes the classes Hydrozoa, Scyphozoa, Staurozoa and Cubozoa, and possibly the parasitic Polypodiozoa. Medusozoans are distinguished by having a medusa sta ...

subphylum of

Cnidaria Cnidaria () is a phylum under kingdom Animalia containing over 11,000 species of aquatic animals found both in freshwater and marine environments, predominantly the latter. Their distinguishing feature is cnidocytes, specialized cells that th ...

. They are unique among medusa jellyfish in that they do not have an alternation of polyp and medusa life cycle phases, but are instead interpreted as an attached

medusa In Greek mythology, Medusa (; Ancient Greek: Μέδουσα "guardian, protectress"), also called Gorgo, was one of the three monstrous Gorgons, generally described as winged human females with living venomous snakes in place of hair. Those ...

stage. With a lifestyle more resembling that of polypoid forms. They have a generally trumpet-shaped body, oriented upside-down in comparison with other jellyfish, with the tentacles projecting upwards, and the stalk located in the centre of the umbrella. Members of this class are commonly found in relatively cold waters, close to the shoreline. Sexually mature stauromedusae free-spawn eggs or sperm, which fertilize in the sea and form a creeping, unciliated

planula A planula is the free-swimming, flattened, ciliated, bilaterally symmetric larval form of various cnidarian species and also in some species of Ctenophores. Some groups of Nemerteans also produce larvae that are very similar to the planula, which ...

larva. The larvae crawl across the sea floor and find a suitable place, attaching themselves typically to rock or algae, where they eventually develop into a new, attached stauromedusa. Unlike most scyphozoan

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- ...

that practice strobilation, or the process of dividing themselves into body segments, which become new individuals, nearly all stauromedusae develop directly into the adult form. Its primary source of food is small organisms, such as copepods, chironomid fly larvae, podocopid ostracods, amphipods, etc. The tendency for the amount of prey consumed increases with the size of the medusae.

Gallery

File:Haliclystus stejnegeri 1.jpg, ''Haliclystus sp.'' File:Haliclystus antarcticus 1C.jpg, ''

Haliclystus antarcticus ''Haliclystus'' is a genus of stalked jellyfish Stauromedusae are the stalked jellyfishes. They are the sole living members of the class Staurozoa and belong to the medusozoa subphylum of Cnidaria. They are unique among medusa jellyfish in th ...

'' File: Haliclystus_octoradiatus_-_Becherqualle_an_Seegras.jpg , ''

Haliclystus octoradiatus ''Haliclystus octoradiatus'', common name spotted kaleidoscope jellyfish, is a Stauromedusae, stalked jellyfish in the family Lucernariidae. Description The bell of large specimens may be 25mm in diameter. However, specimens with a 10mm bell is ...

'' File: Green subum.jpg, ''

Haliclystus sanjuanensis ''Haliclystus sanjuanensis'' is a species of small (~4 cm) stalked jellyfish found in the Pacific Ocean along the west coast of North America. This species can be found in shallow waters at low tide on soft substrates such as seagrass (''Phy ...

'' File:6 or-Manania handi.tif, ''

Manania handi ''Manania handi'' is a species of stalked jellyfish found in the Pacific Ocean along the west coast of North America. This species can be found in shallow waters at low tide on soft substrates such as seagrass (''Phyllospadix''), but the related ...

'' File:Stalked jelly1.jpg, '' Depastromorpha africana'' File:Lucernaria quadricornis.jpg, '' Lucernaria quadricornis'' File:Bell stalked jelly1.jpg, '' Lipkea spp.''

References

Bibliography

Introduction to Stauromedusae

* agal, C. J. (2004). Diet of the stauromedusa Haliclystus auricula from southern Chile. Journal of the Marine Biological Association of the United Kingdom, 84(2), 337-340.h1>

External links

Staurozoan: The Stalked Jellyfish , Smithsonian Ocean Portal
{{Taxonbar, from=Q1060589 Staurozoa Ediacaran first appearances Taxa named by Ernst Haeckel