| Lychnorhiza lucerna | |
|---|---|
 | |
Scientific classification  | |
| Kingdom: | Animalia |
| Phylum: | Cnidaria |
| Class: | Scyphozoa |
| Order: | Rhizostomeae |
| Family: | Lychnorhizidae |
| Genus: | Lychnorhiza |
| Species: | L. lucerna |
| Binomial name | |
| Lychnorhiza lucerna | |
Lychnorhiza lucerna is a species of jellyfish in the order Rhizostomeae. It is found off the Atlantic coasts of South America.
When small, Lychnorhiza lucerna has a hemispherical bell, but this becomes flattened into a saucer shape as the jellyfish grows. Very large specimens have been known to reach 45 centimetres (18 in) in diameter and are dish-shaped. The upper surface is flexible and thin and is covered in low conical projections. Round the periphery are many small, triangular lappets. Hanging under the bell there are four pairs of oral tentacles, about two thirds as long as the diameter of the bell. The upper halves of these are somewhat flattened and the lower halves divide into three vanes which have multiple, inrolled edges. Among these are suctorial mouthlets leading to the interior of the bell and various thick dangling filaments. There is no central mouth. The stomach occupies most of the interior of the bell and there are a ring of small cream or white gonads round its edge. The colouration of this jellyfish varies, but in general, the bell is translucent and colourless or a pale shade of buff, sometimes with irregular streaks of light brown. The dangling lappets round the edge of the bell are darker brown and the lower parts of the oral tentacles may be brown as well, the upper parts being colourless. [2]
Lychnorhiza lucerna is found in tropical waters in the western Atlantic Ocean. Its range extends from French Guiana to Buenos Aires Province in Argentina. It occurs in shallow coastal habitats and estuaries and is the most abundant jellyfish in its order (Rhizostomeae) in these waters. It often becomes stranded on beaches. [3]
Lychnorhiza lucerna has a complex life cycle with an alternation of sexual and asexual stages. An adult jellyfish is known as a medusa and is gonochoristic, which means that it is either male or female. The fertilized eggs hatch into planula larvae. These soon settle and undergo metamorphosis into sessile polyps, known as a scyphistomae, with four tentacles. These grow larger, and after a series of moults have twenty-two tentacles. They develop cysts from which new polyps known as ephyrae grow. These develop transverse constrictions and separate from the original polyp by strobilation. The scyphistomae can strobilate several times and in a study it was estimated that one founder polyp could produce up to sixty ephyrae in a period of four months. Ephyrae develop into juvenile medusae after a further fifteen days or so. [3]
Lychnorhiza lucerna has associations with the parasitic flatworm Dibothriorhynchus dinoi, shrimps Periclimenes spp, the Atlantic bumper fish, Chloroscombrus chrysurus and the bluntnose jack, Hemicaranx amblyrhynchus . [3] Young spider crabs, Libinia ferreirae and Libinia spinosa , use the inside of the bell as a nursery where they are safe from predation. [4]
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-shaped bells and trailing tentacles, although a few are anchored to the seabed by stalks rather than being mobile. The bell can pulsate to provide propulsion for highly efficient locomotion. The tentacles are armed with stinging cells and may be used to capture prey and defend against predators. Jellyfish have a complex life cycle; the medusa is normally the sexual phase, which produces planula larva that disperse widely and enter a sedentary polyp phase before reaching sexual maturity.
The Scyphozoa are an exclusively marine class of the phylum Cnidaria, referred to as the true jellyfish.
The lion's mane jellyfish, also known as the giant jellyfish, arctic red jellyfish, or the hair jelly, is one of the largest known species of jellyfish. Its range is confined to cold, boreal waters of the Arctic, northern Atlantic, and northern Pacific Oceans. It is common in the English Channel, Irish Sea, North Sea, and in western Scandinavian waters south to Kattegat and Øresund. It may also drift into the southwestern part of the Baltic Sea. Similar jellyfish – which may be the same species – are known to inhabit seas near Australia and New Zealand. The largest recorded specimen was measured off the coast of Massachusetts in 1870 and had a bell with a diameter of 210 centimetres and tentacles around 36.6 m (120 ft) long. Lion's mane jellyfish have been observed below 42°N latitude for some time in the larger bays of the east coast of the United States.
Rhopalia are small sensory structures of certain Scyphozoan and Cubozoan species.
Rhizostomae or 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.
Pelagia noctiluca is a jellyfish in the family Pelagiidae and the only currently recognized species in its genus. 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 means 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.
Atolla wyvillei, also known as the Atolla jellyfish or Coronate medusa, is a species of deep-sea crown jellyfish. It lives in oceans around the world. Like many species of mid-water animals, it is deep red in color. This species was named in honor of Sir Charles Wyville Thomson, chief scientist on the Challenger expedition.
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 scyphozoan jellyfish, commonly called moon jellies. There are currently 25 accepted species and many that are still not formally described.
Drymonema is a genus of true jellyfish, placed in its own family, the Drymonematidae. There are three species: Drymonema dalmatinum, Drymonema gorgo, and Drymonema larsoni, which are found in the Gulf of Mexico, Atlantic Ocean and Mediterranean Sea.
Libinia ferreirae is a species of tropical spider crab in the family Epialtidae. It is found on the seabed in shallow waters off the Atlantic coast of South America.
Hemicaranx amblyrhynchus is a tropical marine fish in the jack family (Carangidae). It is found in shallow parts of the western Atlantic Ocean.
Copula is a monotypic genus of box jellyfish in the family Tripedaliidae of the phylum Cnidaria. The only species in the genus is Copula sivickisi, a very small gelatinous, bell-shaped organism with four tentacles that is active only at night. It is unusual among box jellyfish in having a mating ritual and internal fertilisation. The specific name honours the Lithuanian zoologist Pranciškus Baltrus Šivickis.
Rhopilema verrilli, or mushroom cap jellyfish, is a species of jellyfish in the family Rhizostomatidae. They are cnidarian invertebrates distinguished by their mushroom-shaped medusae. The species does not have any tentacles; however, they still have stinging cells, called nematocysts, within their bells, which can produce mild stings to humans.
Sanderia malayensis is a species of jellyfish in the family Pelagiidae, native to the tropical Indo-Pacific. It has a complex life cycle and is thought to be venomous and to have caused injuries to humans.
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.
Cassiopea ornata are one of many Cnidarian species called the upside-down jellyfish. This pelagic jellyfish primarily lives in tropical waters, off the coast of Australia in shallow lagoons and around mangrove trees. The name "upside-down jellyfish" comes from the fact that it appears to be upside-down in its natural state—resting on its bell. Its bell is a golden/brown color and the tentacles vary with different shades of yellow. While the sighting of this particular species is rare, it is usually mistaken for vegetation like the other species in genus Cassiopea.
Cephea cephea, the crowned jellyfish, is a species of jellyfish in the family Cepheidae. It occurs in the tropical waters of the western Indo-Pacific to Northern Australia. The species was first described by Peter Forsskål in 1775 and originally given the name Medusa cephea. It inhabits the pelagic zone of tropical and sub-tropical waters and is most commonly found in the Indo-West Pacific, eastern Atlantic and the Red Sea. Although this species is among the most venomous jellyfish, it is not harmful to humans and is eaten as a delicacy and used for medical purposes in China and Japan. The species can achieve a diameter of up to 60 cm.
Desmonema is a genus of jellyfish under the Cyaneidae family found in colder waters near the Antarctic region and off of the coast of Argentina. They have a bell diameter that can extend over 1 meter and wide tentacles that are grouped together in clusters. They share similar anatomical and physiological structures to the genus Cyanea. Their sophisticated structures like the thick tentacles, sensory systems, and gastrovascular system allow Desmonema to easily capture and extracellularly digest their prey. In recent years, Desmonema were reported to have a commensal relationship with fishes under the Trachurus genus and a parasitic relationship with specimens of the Hyperia genus.