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Staurozoa
Staurozoa is a class of Medusozoa (or jellyfish). 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 highly speculative. This extinct order is largely unknown and described as a possibly cnidarian clade of marine life with shell-like structures. Staurozoans are small animals () that live in marine environments, usually attached to seaweeds, rocks, or gravel.Collins, A. G. (n.d.). Staurozoa. ''AccessScience''. doi:10.1036/1097-8542.652700 They have a large antitropical distribution, a majority found in boreal or polar, near-shore, and shallow waters. Few staurozoans are found in warmer tropical and subtropical water environments of the Atlantic, Indian, and Pacific Ocean basins, but most are known from the Northern Hemisphere. Over the years the number of discovered species has increased, with an estimated 50 species currently recognized. Information ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cnidaria
Cnidaria ( ) is a phylum under kingdom Animalia containing over 11,000 species of aquatic invertebrates found both in fresh water, freshwater and marine environments (predominantly the latter), including jellyfish, hydroid (zoology), hydroids, sea anemones, corals and some of the smallest marine parasites. Their distinguishing features are an uncentralized nervous system distributed throughout a gelatinous body and the presence of cnidocytes or cnidoblasts, specialized cells with ejectable flagella used mainly for envenomation and capturing prey. Their bodies consist of mesoglea, a non-living, jelly-like substance, sandwiched between two layers of epithelium that are mostly one cell (biology), cell thick. Cnidarians are also some of the few animals that can reproduce both sexually and asexually. Cnidarians mostly have two basic body forms: swimming medusa (biology), medusae and sessility (motility), sessile polyp (zoology), polyps, both of which are radially symmetrical with mou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Medusozoa
Medusozoa is a clade in the phylum Cnidaria, and is often considered a subphylum. It includes the classes Hydrozoa, Scyphozoa, Staurozoa and Box jellyfish, Cubozoa, and possibly the parasitic Polypodium (animal), Polypodiozoa. Medusozoans are distinguished by having a medusa stage in their often complex life cycle, a medusa typically being an umbrella-shaped body with stinging tentacles around the edge. With the exception of some Hydrozoa (and Polypodiozoa), all are called jellyfish in their free-swimming Jellyfish#Life history and behavior, medusa phase. Evolution The phylum Cnidaria is widely accepted as being Monophyly, monophyletic and consisting of two clades, Anthozoa and Medusozoa. Anthozoa includes the Class (biology), classes Hexacorallia, the hard corals, and Octocorallia, the soft corals, as well as Tube-dwelling anemone, Ceriantharia, the tube-dwelling anemones. There is strong support for this group having been the first to branch off from the ancestral line. Meduso ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jellyfish
Jellyfish, also known as sea jellies or simply jellies, are the #Life cycle, medusa-phase of certain gelatinous members of the subphylum Medusozoa, which is a major part of the phylum Cnidaria. Jellyfish are mainly free-swimming marine animals, although a few are anchored to the seabed by stalks rather than being motile. They are made of an umbrella-shaped main body made of mesoglea, known as the ''bell'', and a collection of trailing tentacles on the underside. Via pulsating contractions, the bell can provide propulsion for animal locomotion, locomotion through open water. The tentacles are armed with cnidocyte, stinging cells and may be used to capture prey or to defend against predators. Jellyfish have a complex biological life cycle, life cycle, and the medusa is normally the sexual phase, which produces planula larvae. These then disperse widely and enter a sedentary #Life cycle, polyp phase which may include asexual budding before reaching sexual maturity. Jellyfish ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 ('' Phyllospadix''). A variety of colour morphs can be found ranging from yellow-green to red. ''Haliclystus sanjuanensis'' was formally described as a distinct species in 2023, following sequence data establishing it as a distinct taxon. Gallery Colour morphs of ''Haliclystus sanjuanensis'': File: Green subum.jpg , Green File: Grorange subum.jpg , Green-orange File: Orange exum 3.jpg , Orange File: Red exum.jpg , Red File: Inverted Hali stretched mesoglea maybe - buckling of flesh 2.tif , Juvenile ''H. sanjuanensis'' with peach colouring File: Peachy Haliclystus 7b.jpg , Juvenile ''H. sanjuanensis'' with peach colouring References Haliclystidae {{Staurozoa-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stauromedusae
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 that they do not have an alternation of polyp and medusa life cycle phases, but are instead interpreted as an attached medusa 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. Stauromedusae usually has eight marginal arms at the top of the calyx. They reach their adult sizes within several weeks, typically 1 to 4 centimeters in length. Members of this class are commonly found in relatively cold waters, close to the shoreline. However, there are a few known species that inhabit tropical and subtropical waters as referenced in the Stauromedusae article by Claudia E. Mills and Yayoi M. Hiran ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 '' M. gwilliami'' have also been recovered at depths of >10 metres. This may reflect that intertidal specimens represent the fringes of a population that is typically more commonly found in the subtidal zone. Description ''Manania handi'' reaches a length of up to 4 cm, but the diameter of the bell at the oral end is relatively narrow at approximately 2 cm in fully-grown specimens. Distinctive pigment bands along the calyx and the relatively short stalk (or peduncle) distinguish it from related '' Manania'' species. ''Manania handi'' is also described typically as green with cream coloured gonads and vivid white nematocyst vesicles. However the colour patterns of M. handi can vary from brownish-yellow to vivid green. The nam ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Haliclystus Antarcticus
''Haliclystus antarcticus'' is a Stauromedusae, stalked jellyfish which lives on rocky shore lines in the Southern hemisphere. Description The original type specimens for this species have been lost. however the species was re-described in 2009. Individuals vary in colour from red-orange with light red gonads (individuals found at King George Island (Antarctica), King George Island, Antarctica) to red and/or green (individuals found in Valdivia, Chile). ''Haliclystus antarcticus'' has a 'stalk' (peduncle) which is a half to two thirds the length of its Calyx (anatomy), calyx. The inside of the peduncle is divided into four chambers. The calyx itself is about 3.5–16.2 mm tall and 4.1–23.4 mm wide. It is cone shaped and semi-translucent with a smooth outer surface. The animal has eight arms arranged in pairs which radiate out from a central four sided mouth. The arms are 0.3–6.0 mm in length. Each arm is tipped by clusters of up to roughly 200 tentacles wh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Haootia
''Haootia quadriformis'' is an extinct animal belonging to the Ediacaran biota. Estimated to be about 560 million years old, ''H. quadriformis'' is identified as a cnidarian polyp, and represents the earliest known evidence for muscle tissue in an animal. Discovered in 2008 from Newfoundland in eastern Canada, it was formally described in 2014. It is the first Ediacaran organism discovered to show fossils of muscle fibres. Structural examination of the muscles and morphology indicate that the animal is a cnidarian, though, which class ''H. quadriformis'' belongs to was undetermined until a 2024 study found it to be a staurozoan. Discovery and name The first fossil of ''Haootia'' was discovered from lower Fermeuse Formation of Back Cove, Bonavista Peninsula in Newfoundland. It was originally unearthed by Martin D. Brasier of the University of Oxford in 2008. However, the specimen was not allowed to be removed according to provincial law in Newfoundland, so that only a pl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mamsetia
''Mamsetia manunis'' is an extinct cnidarian from the late Ediacaran. Estimated to be about 565 million years old, ''M. manunis'' is identified as a cnidarian polyp, and represents some of the earliest known evidence for muscle tissue in an animal. Its fossil was discovered in 2014 from Newfoundland in eastern Canada, and was formally described in 2024 as a staurozoan based on examination of its overall morphology and structure. Discovery and name The now-holotype fossil of ''Mamsetia'' was originally the paratype fossil for ''Haootia'' from the Trepassey Formation of Green Island, Bonavista Peninsula in Newfoundland. However, with the publication of a new paper in 2024 placing ''Haootia'' as a staurozoan, it was discovered that the paratype had enough differences in its morphology to that of ''Haootia'' to erect a new genus. The generic name ''Mamsetia'' is derived from the Beothuk word ''Mamset'', meaning "living". The specific name ''manunis'' is derived from the Beothu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Conulariida
Conulariida are an extinct group of medusozoan cnidarians known from fossils spanning from the latest Ediacaran up until the Late Triassic. They are almost exclusively known from their hard external structures (alternatively referred to as a theca, periderm or test), which were pyramidal in shape and made up of numerous lamellae (thin layers). They are thought to have been sessile animals that grew with the narrower tip anchored to the seafloor, with the wider end bearing an array of tentacles used to ensnare prey. Structure The conulariids are fossils preserved as shell-like structures made up of rows of calcium phosphate rods, resembling an ice-cream cone with fourfold symmetry, usually four prominently-grooved corners. New rods were added as the organism grew in length; the rod-based growth falsely gives the fossils a segmented appearance. Exceptional soft-part preservation has revealed that soft tentacles protruded from the wider end of the cone, and a holdfast from the p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
