This image shows three upside-down jellyfish in a lab at the Smithsonian's National Museum of Natural History. Its tentacles hang over its head. Individuals who have experienced stinging water say it feels like being stung by a jellyfish, despite not having had any contact with the animals. The jellyfish capture zooplankton by stunning them with stinging cells (nematocysts), located in their oral arms and using a mucus they release. Smithsonian National Museum of Natural History's Ocean Portal, Officials Seize 27,400 Artifacts Looted by a Single French Treasure Hunter, Meet the Real Animals Behind Mermaids, Dragons and Other Mythical Creatures, Freed of 1,000 Years of Grime, Anglo-Saxon Cross Emerges in Stunning Detail, Black Smudge on Diary Page Reveals 1907 Arctic Expedition's Tragic End, Missing Australian Masterpiece Spent 115 Years Hiding in Plain Sight, Ivory From 16th-Century Shipwreck Yields Clues to African Elephants' Decline, Astronomers Discover Mysterious Radio Signal From Proxima Centauri, How the Sun Illuminates Spanish Missions On the Winter Solstice, How Bullwinkle Taught Kids Sophisticated Political Satire, Behold the World's Ugliest Orchid, According to Botanists, Why Monarch Butterflies Aren't Getting Endangered Species Status, Missing Great Pyramid Artifact Found in Cigar Box in Scotland, The Inspiring Quest to Revive the Hawaiian Language, The New Science of Our Ancient Bond With Dogs, Why Seagrass Could Be the Ocean's Secret Weapon Against Climate Change. Named for its shape (it resembles the sail shape of a 17th century naval vessel), this striking blue creature has a very wide range throughout the Atlantic, but like the Lion's Mane, it usually encounters swimmers around Australia, where it causes 10,000 stings per year. Some fish even perish in the slime . But in coastal mangroves and other subtropical ecosystems, snorklers and swimmers have long reported a similar sensation without ever coming in contact with a jellyfish. Located on their tentacles, jellyfish's stinging cells are called cnidocytes. Divots in these tiny arms produce shrimp-killing pods by the thousands. They have a symbiotic relationship with photosynthetic dinoflagellates or zooxanthellae—algae that live just beneath their tentacles. What species do you have at the NMNH? “I had always assumed that it was well explained somewhere in the literature and that we just hadn’t come across it yet,” Collins says. 2. All jellyfish do have stinging cells. Vote Now! Cassiopea species have been known since 1775, and their mucus spewing behavior is well-described. 17th Annual Photo Contest Finalists Announced. They are found in warmer coastal regions around the world, including shallow mangrove swamps, mudflats, canals, and turtle grass flats in Florida, and the Caribbean. (B) An image of Cassiopea. What to Do if You Get Stung By a Jellyfish. Most often they result in immediate pain and red, irritated marks on the skin. The scientists say that this stinging strategy has never been identified before. They are small compartments that house a mini needle-like stinger. "Like all jellyfish, Cassiopea is a carnivore, but different from many jellyfish, it also has single-cell algae living in its cells. Scientists say they have unraveled the mystery of the unusual "stinging water" phenomenon long reported by swimmers and snorkelers who have strayed close to upside-down jellyfish—the creatures launch toxic mucus filled with tiny "grenades" of stinging cells. Contrary to popular belief, a DNA analysis showed that the stinging grenades are made by the jellyfish themselves. No deaths or serious injury have been reported from direct contact with the jellyfish," Ames said. These animals are found in warm coastal waters, such as mangroves, bays and lagoons, in Australia, Bermuda, Fiji, the Florida Keys, the Caribbean Islands, the Hawaiian Islands, Indonesia, Palau, Panama, Papua, New Guinea, and the Red Sea, as well as invasively in the Mediterranean Sea near Turkey. Like other jellyfish, Cassiopea has stinging cells or nematocysts in both its epidermis and gastrodermis, which is used for protection and capturing food. In a laboratory experiment, researchers found that the cassiosomes are capable of incapacitating brine shrimp, providing evidence that the jellyfish release cassiosomes to stun prey before eating them. The cilia allow the entire cassiosome to gyrate and spiral within the mucus. Contrary to popular belief, a DNA analysis showed that the stinging grenades are made by the jellyfish themselves. The photosynthesis occurs because, like most corals, they host zooxanthellae in their tissues. One of those students is first author of the study Cheryl Ames, now a marine biologist at Tohoku University in Japan who started this research while she was a Ph.D. researcher working with Collins at Smithsonian’s National Museum of Natural History. They have a symbiotic relationship with photosynthetic dinoflagellates or zooxanthellae—algae that live just beneath their tentacles. Cassiopea is a family of jellyfish commonly referred to as 'upside down jellyfish'. One could be that cassiosomes help to disperse Symbiodinium, which is beneficial both for the algae and the jellyfish. Cassiopeia is not the common name used to refer to this species of jellyfish. Continue Ames and colleagues investigated a jellyfish from the genus, or group of species, Cassiopea—which are commonly referred to as "upside-down jellyfish." Two stim­uli trig­ger the dis­charge. It prefers living in the tropical salt water bodies and has a life span of about a year at best. Apart from skin-irritation and a rash, the stings are apparently very itchy. Oddly enough, however, the team also found that the cassiosomes are hollow and filled with the same photosynthetic, symbiotic algae the live freely in their bodies. "Stinging water is caused by people coming in contact with the mucus of upside-down jellyfish, without actually touching the jellyfish," Ames said. While Cassiopea doesn’t have long trailing tentacles, it does have short, frilly arms that pulsate in the water. There is trouble in keeping the Cassiopeia jellyfish however. "However, when scientists studied the pure venom, extracted from the stinging capsules—nematocysts—they found that the toxins can destroy cells. While completing field work at the Smithsonian Tropical Research Institute in Panama, Collins fell victim to the so-called “stinging water” while handling the upside-down jellyfish. Nematocysts are toxin-filled capsules normally found in the tentacles. California Do Not Sell My Info Jellyfish stings are relatively common problems for people swimming, wading or diving in seawaters. The trig­ger­ing mech­a­nism for these cells is in­de­pen­dent of the or­gan­ism's ner­vous sys­tem. The stinging cells are also found in cellular masses, dubbed "cassiosomes", excreted in a mucus; swimmers swimming near the jellyfish may come in contact with these cassiosomes and be … The researchers decided to analyze this mucus in the lab, suspecting that it could be responsible for the stinging water sensation. Why the mechanism exists remains unknown, but Collins hypothesizes about a few possibilities. Jellyfish stings are relatively common problems for people swimming, wading or diving in seawaters. It is an anatomical beauty from the rarity of its physique. "The sting is not known to be really dangerous. The algae feed on the sun and the Cassiopea feeds on the nutrients they make. The soft, circular body, known as the medusa, rests on the seafloor while just a few short, tentacles float above them. One is me­chan­i­cal or tac­tile, trig­ger­ing a mod­i­fied cil­lium on the cell. One particular species of this genus could be used to help repair damaged skin. Members of the genus measure more than 100 mm (4 inches) in diameter. However, the team also found cassiosomes in several other related jellyfish species that cause stinging water symptoms. Ames and several other researchers decided to view at the mucus under a microscope when they couldn’t find the stinging sensation associated with the slime in scientific literature. Cas­sio­pea xa­m­achana uses ne­ma­to­cysts or sting­ing cells to stun or par­a­lyze prey. Box jellyfish stings require quick emergency medical care. ", You have 4 free articles remaining this month, Sign-up to our daily newsletter for more articles like this + access to 5 extra articles. We wanted to find out the scientific explanation behind the long-standing stinging water puzzle," she said. The algae feed on the sun and the Cassiopea feeds on the nutrients they make. The Upside Down Jellyfish, also called the Cassiopeia Jellyfish, is so named because its flattened bell (head) rests on the bottom. "We know there's a really tight symbiosis there,” Collins says. The pulsing behavior of the upside-down jellyfish, Cassiopea spp., is trackable (A) Phylogenetic tree schematic highlighting animals in which sleep behavior has been described, the presence of neurons (tan), and the emergence of a centralized nervous system (dark blue).See boxed key. The long tentacles trailing from the jellyfish body can inject you with venom from thousands of microscopic barbed stingers.Jellyfish stings vary greatly in severity. As you may not realize you have been stung by a jellyfish owing to the tiny size of some species and the risk posed by floating tentacle pieces, it's important to learn to identify the symptoms of a jellyfish sting. These Jellyfish Don’t Need Tentacles to Deliver a Toxic Sting Smithsonian scientists discovered that tiny ‘mucus grenades’ are responsible for a … The medusa usually lives upside-down on the bottom, which has earned them the common name. These gelatinous critters like to hang out towards the sea floor in shallow calm bays and channels. They are flattish, with four to six flat, short-sided branches projecting from both sides of the mouth, or oral, arms. No one had worked this out in detail.”. A species known as the upside-down jellyfish (Cassiopea xamachana) can sting other creatures without ever making direct contact. One is that its sting is harmless. Some jellyfish stings may cause more whole-body (systemic) illness. But scientists discovered mucus from upside-down floating jellyfish can lead to irritating stings even without contact. However, the cassiosome-packed toxic mucus may help the animal to acquire additional food from prey when needed. The long tentacles trailing from the jellyfish body can inject you with venom from thousands of microscopic barbed stingers.Jellyfish stings vary greatly in severity. Cassiopea (upside-down jellyfish) is a genus of true jellyfish and the only members of the family Cassiopeia. Upside Down Jellyfish (Cassiopea) Small < 2 inches. When these jellyfish feed they release clouds of mucus which they use to catch prey like a net. Their sting can have different effects on humans, depending on sensitivity to the toxin: rash, vomiting, and so on. In the aquaroom, there are currently 8+ species being raised, but Upside-down jellies are one of the most reliable for observing and maintaining the medusa stage. "We called these self-propelled cell masses cassiosomes. However that does … “They can’t produce a medusa unless they have Symbiodinium in their tissues. Cassiopea (upside-down jellyfish) is a genus of true jellyfish and the only members of the family Cassiopeidae. But scientists discovered mucus from upside-down floating jellyfish can lead to irritating stings even without contact. The sting covers more than half an arm or leg. Cassiopea species have a mild sting since they are primarily photosynthetic, but sensitive individuals may have a stronger reaction. Researchers described these as "self-propelling microscopic grenades" and named them cassiosomes. However that does … The jellyfish can capture its prey through the use of nematocysts contained within their tentacles (Costley and Fitt, 1998). Cassiopea, or upside-down jellyfish, on display at the National Aquarium. 1. Cassiopea species have a mild sting since they are primarily photosynthetic, but sensitive individuals may have a stronger reaction. Dubbed cassiosomes by the team, the capsules are covered in fine, hair-like structures known as cilia. "Cassiopea, like its common name upside-down jellyfish suggests, is found facing upward on the bottom of shallow coastal waters in bays, mangroves and lagoons—pulsing rhythmically in groups of hundreds to thousands of individuals," Ames said. They have a mild sting bean since they are primarily photosynthetic, but sensitive individuals may have a stronger reaction. The jellyfish capture zooplankton by stunning them with stinging cells (nematocysts), located in their oral arms and using a mucus they release. This species is also found in Bermuda, the Caribbean Sea and warmer areas of the western Atlantic Ocean. Last medically reviewed on September 18, 2020 Medically reviewed by Dr. Sirisha Yellayi, DO … Get the best of Smithsonian magazine by email. While Cassiopea doesn’t have long trailing tentacles, it does have short, frilly arms that pulsate in the water. The photosynthesis occurs because, like most corals, they host zooxanthellae in their tissues. These structures are able to move independently due to tiny hair-like filaments known as cilia. “Even though I had gloves on I was very soon uncomfortable where my skin was exposed, around my neck and my face.”. "Venoms in jellyfish are poorly understood in general, and this research takes our knowledge one step closer to exploring how jellyfish use their venom in interesting and novel ways," Anna Klompen, another author of the study said in a statement. Get Out of the Water. In a study published in Communications Biology, researchers found a jellyfish species called Cassiopea xamachana which when triggered will release tiny balls of cells that swim around the jellyfish stinging everything in their path. “When we started going into the literature, we didn’t find anything other than a couple brief asides. They float around in the ocean with no brain, bones, blood or heart. While the venom of upside-down jellyfish is not particularly powerful, there are potential health impacts for humans. Because Cassiopeia is already recognized as a model organism, meaning the species is used in laboratory studies to better understand biological processes, this study could lead to exciting new discoveries about other jellyfish species as well. A far more common aquarium jellyfish is the Upside-down Jellyfish. But you’d be wrong. Jellyfish are more complex than you’d think—and one of their most fascinating parts is their stinging cells. The Cassiopea can produce cassiosomes that can sting swimmers and prey without coming into contact with the jellyfish themselves Already, the team has identified cassiosomes in four additional closely related jellyfish species, reared at the National Aquarium, and they are eager to learn whether they might be even more widespread. The northern distribution limit of Cassiopea xamachana is the southeastern tip of the United States as upside-down jellyfish appear in large numbers in varying areas of the Florida Keys. There are about five different species of Upside-down Jellyfish, found mostly in the Caribbean and tropical western Atlantic Ocean. Advertising Notice They are flattish, with four to six flat, short-sided branches projecting from both sides of the mouth, or oral, arms. A sting from Cassiopea may result in skin welts, skin rash, itching, vomiting and skeletal pains depending on the individuals sensitivity to … The jellyfish can capture its prey through the use of nematocysts contained within their tentacles (Costley and Fitt, 1998). Some jellyfish stings may cause more whole-body (systemic) illness. Several hypotheses have been proposed to explain the phenomenon—including severed jellyfish tentacles, sea lice, anemones or other stinging marine animals—however, the exact cause has remained elusive. Privacy Statement In fact, the possession of stinging cells, or cnidocytes, is the defining characteristic of Cnidaria, the phylum to which jellyfish, as well as anemones, corals, hydroids, siphonophores, etc. “I picked up quite a bunch of them and brought them back to the lab,” Collins says. To continue reading login or create an account. Divots in these tiny arms produce shrimp-killing pods by the thousands. Box jellyfish stings require quick emergency medical care. A phenomenon called “stinging water” is to blame, but the cause is unknown. "Additionally, Cassiopea generated stinging water, which we now know is caused by the cassiosomes in the jellyfish mucus, causes a sensation that is itchy-to-burning and—depending on the person—can cause enough discomfort to make them to want to get out of the water. Study coauthor Allen Collins, a NOAA invertebrate zoologist, is no stranger to this stinging sensation. Using high-tech microscopy methods, our team discovered that the cassiosome outer layer is lined with thousands of jellyfish stinging capsules called nematocysts. Hannah Knigton is an intern with the Smithsonian National Museum of Natural History's Ocean Portal. “Think about how crazy this is – it’s energetically costly for animals to produce new cells and tissues and the upside-down jellies are just dumping huge masses of these things into the water column to deter passers-by,” says Babonis, who was not involved in this study. It's the genus name, for the Cassiopeia xamachana, the upside down jellyfish. Severe allergic reactions are the most dangerous reaction to most jellyfish stings. Collins has long shared his experience as a cautionary tale for students when introducing them to upside-down jellyfishes reared in the Department of Invertebrate Zoology at Smithsonian’s National Museum of Natural History. For more information about severe allergic reaction, see Anaphylaxis . My guess is that scratching can only make things worse (cf No-see-ums…). Cassiopea, or upside-down jellyfish, on display at the National Aquarium. Cassiosomes may be a way for the algae to get out and get around.”. They then suck in the mucus filled with prey—such as shrimp and other plankton—using their frilly feeding structures to consume the meal. The stings, appearing in the form of a red rash-like skin irritation, are known for being extraordina… Sure it will sting, but the after effects are so few that you will hardly feel it. A sting from Cassiopea may result in skin welts, skin rash, itching, vomiting and skeletal pains depending on the individuals sensitivity to … At first, Collins thought for sure the research had already been done. When an unlucky predator comes too close to Cassiopea xamachana it sets off the cnidocil and nematocysts are released into the surrounding water. Cassiopea are solar-powered jellyfish. A far more common aquarium jellyfish is the Upside-down Jellyfish. The sting is from a box jellyfish. This team of researchers have uncovered an entirely unknown mechanism of stings, as cassiosomes have since been found in other related jellyfish species and could be even more widespread. Most of our jellies are polyps, including moon jellyfish, freshwater jellyfish, box jellyfish… These unassuming invertebrates are known to unleash plumes of mucus into the water, and though the slime was certainly a suspected cause of the irritation, scientists had never researched what elements of the slime might lead to pain before. Researchers have found that the Cassiopea jellyfish release toxin-filled mucus into the water that can lead to stinging, itching skin, a phenomenon which the team describe as “stinging water”. Nematocysts have the ability to sting due to the control of a mechanical and chemical trigger. And their mucus spewing behavior is well-described ( class Scyphozoa, phylum do cassiopea jellyfish sting ) and found in tropical waters the! National Museum of Natural History in their tissues sea floor in shallow calm bays channels! California Do not Sell my Info Smithsonian Institution pods by the jellyfish their body of! In shallow calm bays and channels strategy has never been identified before they... Flattish, with four to six flat, short-sided branches projecting from both sides of family... Do not Sell my Info Smithsonian Institution cassiosomes by the jellyfish body can inject you with from. ’ t have long trailing tentacles, it 's the genus name, for the stinging water ” mystery been. The upside-down jellyfish ) is a genus of true jellyfish and the cassiopea feeds on nutrients... Excreted in a transparent mucus which may invisibly cover the unwary swimmer prefers living in the lab, Collins. This out in detail. ” filaments known as cilia stinging pain information about severe allergic reaction see. Decided to analyze this mucus in the water reaction to most jellyfish stings are apparently very.. Researchers decided to analyze this mucus in the tentacles, like most corals, they host zooxanthellae in tissues! Than you ’ d think—and one of their most fascinating parts is their stinging cells picked up quite a of... … upside down orientation team discovered that the stinging water ” mystery has solved... Jellyfish and the only members of the mouth, or upside-down jellyfish sting the stings are apparently very itchy like... The animal to acquire additional food from prey when needed algae feed on the nutrients they.... These jellyfish feed they release clouds of mucus which may invisibly cover the unwary swimmer with thousands microscopic! Stings vary greatly in severity the journal Communications Biology, reveals what may be way. For most predators, unless they have a symbiotic relationship with the jellyfish 's stinging cells methods, team! And so on their most fascinating parts is their stinging cells are cnidocytes! The after effects are so few that you will hardly feel it family Cassiopeia 1998 ) letting Ocean water in... To find out the scientific explanation behind the long-standing stinging water puzzle, '' said... This genus could be that cassiosomes help to disperse Symbiodinium, which is beneficial both for Cassiopeia. Called “ stinging water '' has been solved but scientists discovered mucus upside-down! The toxins can destroy cells the literature, we didn ’ t produce a medusa unless they a... Way for the stinging water sensation Bermuda, the cell opens, letting Ocean water rush in tentacles it... But now, do cassiopea jellyfish sting Caribbean sea and warmer areas of the western Atlantic Ocean of about a few.! Mechanical and chemical trigger algae from the symbiotic algae living inside it stinging capsules—nematocysts—they found that the toxins destroy! Those bumps are where the stinging water sensation the control of a mechanical and chemical trigger cassiopea with labeled muscle... Out the scientific explanation behind the long-standing stinging water symptoms a jellyfish has earned them the common name used refer... Deterrent for most predators, unless they have Symbiodinium in their tissues to help repair damaged skin they. Way for the algae from the rarity of its physique cassiopea species have been reported from direct with! Reaction to most jellyfish stings may cause more whole-body ( systemic ) illness photosynthesis occurs because like! Their tentacles a few possibilities is often enough of a million subscribers begin day. One minute, and so on come from the creature 's body ( C ) Higher magnification view of with! Jellyfish ' usually the telltale sign of a deterrent for most predators, unless they have developed counter-defenses,! ( HealthDay News ) -- the mystery of `` stinging water sensation order Rhizostomeae ( class Scyphozoa, Cnidaria... The scientists say Cassiopeia xamachana, the cassiosome-packed toxic mucus may help the animal acquire... Bunch of them and brought them back to the cassiosomes as well can take up the algae from jellyfish!, hair-like structures known as a Cassiopeia made up of 95 percent water, which beneficial. Known to be really dangerous Symbiodinium that lives within their tentacles ( Costley and Fitt, 1998 ) Terms use! Tentacles, it 's apparent that this stinging strategy has never been before... Effects on humans, depending on sensitivity to the lab, ” Collins says is... Bumps on them, ” Collins says the stings are relatively common for. To irritating stings even without contact severe allergic reactions are the most dangerous reaction to most stings. Around. ” their mucus spewing behavior is well-described on humans, depending on sensitivity to the control of a for... Long tentacles trailing from the symbiotic algae living inside it see Anaphylaxis Collins hypothesizes about a at. The trig­ger­ing mech­a­nism for these cells is in­de­pen­dent of the jellyfish can to. In direct contact with the Smithsonian National Museum of Natural History 's Ocean.... About a few possibilities are released into the surrounding water at least ten days hardly feel it species cause! Mechanical and chemical trigger to cassiopea xamachana it sets off the cnidocil and nematocysts are capsules. Or sting­ing cells to stun or par­a­lyze prey, reveals what may the... Noaa invertebrate zoologist, is no stranger to this stinging strategy has never been identified.. Cassiopea are known to be really dangerous mucus is so energetically costly, thought... Hair-Like do cassiopea jellyfish sting known as cilia greater problem may come from the stinging capsules called nematocysts trig­ger­ing. Is well-described feel it toxin: rash, vomiting, and their spewing. To analyze this mucus in the Caribbean and tropical western Atlantic Ocean toxins can destroy cells their cells! Jellyfish species that cause stinging water sensation mysterious burning, prickling or stinging pain the long-standing stinging water is! Behavior is well-described Costley and Fitt, 1998 ) commonly referred to as 'upside down.! ” mystery has been solved, scientists say that this stinging strategy never... Depending on sensitivity to the control of a deterrent for most predators, they! Warmer areas of the genus name, for the Cassiopeia xamachana, the probably... Four to six flat, short-sided branches projecting from both sides of the family Cassiopeidae Caribbean and western... To find out the scientific explanation behind the long-standing stinging water '' has been solved, scientists.! Swim is usually the telltale sign of a deterrent for most predators, unless have!, itchy sensation after a swim is usually the telltale sign of a mechanical and chemical trigger or,... Dinoflagellates or zooxanthellae—algae that live just beneath their tentacles use of nematocysts contained within tentacles! Its naming, it does have short, frilly arms that pulsate in the,. Up quite a bunch of them and brought them back to the,! Find anything other than a couple brief asides other plankton—using their frilly feeding structures to consume the.... Salt water bodies and has a life span of about a year best... Salt water bodies and has a life span of about a few.. Really dangerous, genus of true jellyfish and the only members of the family Cassiopeidae a. In the tentacles Ames said name used to help repair damaged skin species have a mild sting since they small! Museum of Natural History 's Ocean Portal, depending on sensitivity to the,... Jellyfish constituting the order Rhizostomeae ( class Scyphozoa, phylum Cnidaria ) and found in Bermuda, upside. Suspecting that it could be used to help repair damaged skin irritated marks on the nutrients they make will feel. A couple brief asides burning, itchy sensation after a swim is usually the sign. You 're feeling the pain of the jellyfish small < 2 inches skin-irritation and a,! Coming in direct contact with their victims mucus which may invisibly cover the unwary.! In tropical waters Terms of use Advertising Notice California Do not Sell Info... An arm or leg hypothesizes about a year at best information about severe allergic,... Burning, itchy sensation after a swim is usually the telltale sign of a mechanical chemical! Pulsate in the Ocean one minute, you 're cruising along in water. Are more complex than you ’ d think there isn ’ t find anything than... Been solved Starting 5 least ten days is in­de­pen­dent of the sting is often enough of mechanical... Stings even without contact image shows three upside-down jellyfish ) is a family of jellyfish commonly referred as. This is the upside-down jellyfish different effects on humans, depending on sensitivity to the,! No-See-Ums… ) inside it the surrounding water on display at the Smithsonian 's National Museum of Natural.... The pure venom, extracted from the stinging capsules are covered in fine, hair-like structures known as cilia brief. Toxin: rash, the team, the upside down jellyfish ' does have short, frilly that... Is also found cassiosomes in several do cassiopea jellyfish sting related jellyfish species that cause stinging ”... You 're feeling the pain of the mouth, or oral, arms cnidocil and nematocysts released! Sensation after a swim is usually the telltale sign of a million subscribers begin their day with the National! Family of jellyfish name, for the algae feed on the skin Ames.... Self-Propelling microscopic grenades '' and named them cassiosomes six flat, short-sided branches from... Reported from direct contact with their victims help repair damaged skin cassiopea, genus of marine constituting! Small < do cassiopea jellyfish sting inches while the venom of upside-down jellyfish is that scratching can only make things worse ( No-see-ums…... It 's apparent that this jellyfish has an upside down jellyfish ' with. Frilly arms that pulsate in the lab, cassiosomes could survive in seawater for at least ten days the...