Cnidaria is a phylum under kingdom Animalia containing over 11,000 species of aquatic animals found both in fresh water and marine environments, including jellyfish, hydroids, sea anemones, corals and some of the smallest marine parasites. Their distinguishing features are a decentralized 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 thick. Cnidarians are also some of the only animals that can reproduce both sexually and asexually.
Jellyfish, also known as sea jellies, are the medusa-phase of certain gelatinous members of the subphylum Medusozoa, which is a major part of the phylum Cnidaria.
Box jellyfish are cnidarian invertebrates distinguished by their box-like body. Some species of box jellyfish produce potent venom delivered by contact with their tentacles. Stings from some species, including Chironex fleckeri, Carukia barnesi, Malo kingi, and a few others, are extremely painful and often fatal to humans.
Aurelia aurita is a species of the family Ulmaridae. All species in the genus are very similar, and it is difficult to identify Aurelia medusae without genetic sampling; most of what follows applies equally to all species of the genus.
Rhizostomeae is an order of jellyfish. Species of this order have neither tentacles nor other structures at the bell's edges. Instead, they have eight highly branched oral arms, along which there are suctorial minimouth orifices. These oral arms become fused as they approach the central part of the jellyfish. The mouth of the animal is also subdivided into minute pores that are linked to coelenteron.
Nomura's jellyfish is a very large rhizostome jellyfish, in the same size class as the lion's mane jellyfish, the largest cnidarian in the world. It is edible but not considered high quality. It is the only species in the monotypic genus Nemopilema. Commonly found in the waters of East Asia, and can negatively effect fisheries due to their large size and quantity. As a form of combating the large blooms, recent studies attempt to find new uses for the large jellyfish such as studying its venom for medical applications.
Pelagia noctiluca is a jellyfish in the family Pelagiidae and the only currently recognized species in the genus Pelagia. It is typically known in English as the mauve stinger, but other common names are purple-striped jelly, purple stinger, purple people eater, purple jellyfish, luminous jellyfish and night-light jellyfish. In Greek, pelagia means "(she) of the sea", from pelagos "sea, open sea"; in Latin noctiluca is the combining form of nox, "night"", and lux, "light"; thus, Pelagia noctiluca can be described as a marine organism with the ability to glow in the dark (bioluminescence). It is found worldwide in tropical and warm temperate seas, although it is suspected that records outside the North Atlantic region, which includes the Mediterranean and Gulf of Mexico, represent closely related but currently unrecognized species.
Phacellophora camtschatica, commonly known as the fried egg jellyfish or egg-yolk jellyfish, is a very large jellyfish in the family Phacellophoridae. This species can be easily identified by the yellow coloration in the center of its body which closely resembles an egg yolk, hence how it got its common name. Some individuals can have a bell close to 60 cm (2 ft) in diameter, and most individuals have 16 clusters of up to a few dozen tentacles, each up to 6 m (20 ft) long. A smaller jellyfish, Cotylorhiza tuberculata, typically found in warmer water, particularly in the Mediterranean Sea, is also popularly called a fried egg jellyfish. Also, P. camtschatica is sometimes confused with the Lion's mane jellyfish.
Cotylorhiza tuberculata is a species of jellyfish of the phylum Cnidaria, also known as the Mediterranean jellyfish, Mediterranean jelly, or fried egg jellyfish. It is commonly found in the Mediterranean Sea, Aegean Sea, and Adriatic Sea.
Cotylorhiza is a genus of true jellyfish from the family Cepheidae. The genus is found in the central-east Atlantic, Mediterranean, and western Indian Ocean.
Chrysaora hysoscella, the compass jellyfish, is a common species of jellyfish that inhabits coastal waters in temperate regions of the northeastern Atlantic Ocean, including the North Sea and Mediterranean Sea. In the past it was also recorded in the southeastern Atlantic, including South Africa, but this was caused by confusion with close relatives; C. africana, C. fulgida and an undescribed species tentatively referred to as "C. agulhensis".
Aurelia is a genus of jellyfish that are commonly called moon jellies, which are in the class Scyphozoa. There are currently 25 accepted species and many that are still not formally described.
Cyanea is a genus of jellyfish, primarily found in northern waters of the Atlantic and Pacific Oceans and southern Pacific waters of Australia and New Zealand, there are also several boreal, polar, tropical and sub-tropical species. Commonly found in and associated with rivers and fjords. The same genus name has been given to a genus of plants of the Hawaiian lobelioids, an example of a parahomonym.
Aurelia labiata is a species of moon jellyfish. It is a cnidarian in the family Ulmaridae. It is typically larger than Aurelia aurita, with individuals document up to 45 cm (18 in). However, much of its size range overlaps with A. aurita, making size an imperfect diagnostic tool. Most Aurelia labiata have a 16-scalloped bell, meaning the bell indents inward at 16 points, a characteristic that also appears in other Aurelia species. Aurelia labiata occurs in the northeastern Pacific Ocean, from the northern coast of California, north to Canada and into Alaska.
Lipkea is a genus of stalked jellyfish. It is the only genus in the monotypic family Lipkeidae. Lipkea species lack tentacles at the end of their bell.
Rhizostoma is a genus of medium to large rhizostomatid jellyfish found in the East Atlantic Ocean and Mediterranean Sea.
Chiropsoides is a genus of box jellyfish in the family Chiropsalmidae. It is monotypic, with a single species, Chiropsoides buitendijki. The most distinct species characteristics are the shape of the gastric saccules, the pedalial canals, and the unilateral pedalial branching.
The South American sea nettle is a species of jellyfish from the family Pelagiidae. It is found from the Pacific coast of Peru, south along Chile's coast to Tierra del Fuego, and north along the Atlantic coast of Argentina, with a few records from Uruguay. Despite its common name, it is not the only sea nettle in South America. For example, C. lactea is another type of sea nettle in this region. Historically, C. plocamia was often confused with C. hysoscella, a species now known to be restricted to the northeast Atlantic. C. plocamia is a large jellyfish, up to 1 m in bell diameter, although most mature individuals only are 25–40 cm (10–16 in).
Rhizostomins are proteins that are part of a pigment family only found in jellyfish in the order Rhizostomeae. These proteins are composed of a Kringle domain inserted within a cysteine-rich Frizzled domain, first identified in 2004 as the blue pigment in the barrel jellyfish Rhizostoma pulmo. It also appears in rhizostome jellyfish that do not appear blue, such as in Nemopilema nomurai, which typically presents red-brown coloration. It has been hypothesized that pigments in this family act as a sunscreen, protecting from harmful ultraviolet radiation. Natural blue pigments, such as some of the rhizostomins, are rare and there is a growing need for industrial purposes.
Aurelia coerulea or Asian moon jelly is a species of moon jelly in the genus Aurelia. This species is native to the seas off Japan, China, Korea, and California, as well as the Mediterranean and other temperate seas. and they can also be found in coastal areas of China, Korea, California, the Mediterranean and other temperate seas. It is particularly abundant in artificial habitats and sheltered regions. It has a very high reproductive rate which can cause blooming events. A.coerulea blooming causes problems such as impairing fisheries, clogging the nuclear power plants and disrupting the local zooplankton abundance. The chemical compounds the species secretes as a self-defense mechanism can be used for pharmaceutical purposes.
