Greek heroes turned to stone under the gaze of the mythical witch Medusa the Gorgon. Will the real and largest jellyfish in the world, the Arctic cyanea, make you freeze in shock? This floating nightmare has a bell two meters in diameter and extends its tentacles up to 30 meters! Find out the truth about giant jellyfish, their size and lifestyle, and your chances of encountering them in the wild.
First place: Arctic cyanide - the longest animal on the planet
The owner of the longest body prefers the cold waters of the White, Kara and Barents Seas, although he often descends to the latitudes of Boston and northern Portugal. In 1870, residents of one of the villages on the shores of Massachusetts Bay went out to collect fish left on the sand after a storm and discovered a gigantic jellyfish thrown up by the sea.
Animal measurements showed:
- 7.5 feet (2.3 m) - bell span;
- 120 feet (36.6 m) - length of tentacles;
- 121.4 feet (37 m) - total length from crown to tentacle tips.
Even the blue whale does not reach the cyanea record of 3.5 m!
What does a giant jellyfish look like and what does it eat?
The dome of the cyanide, shimmering with a greenish light, is colored burgundy closer to the edges and is divided into 16 lobes. Numerous tentacles of the animal stretch behind the dome in a sloppy pink trail. Thanks to them, the jellyfish received a second name - hairy.
For a person, an encounter with the Arctic giant is fraught with painful burns. National geographical society The United States considers cyanea potentially fatal, although death from its poison has only been recorded once.
Second place: Nomura Bell - the yellow giant from the Yellow Sea
Kanihi Nomura, a zoologist and at the same time director of fisheries in the Japanese prefecture of Fukui, puzzled by the clogging of nets with jellyfish, found and described this species in 1921. The animal resembles a lump of tangled fibers from the central part of a pumpkin fruit, hanging from a two-meter bell. The second name of the giant is lion's mane.
Nomura's tentacles are small, but the mass of one specimen reaches 200 kg. In 2009, a fishing boat capsized off the coast of Japan while the crew was struggling with nomura that had filled the net. The efforts of fishermen to throw the lion's mane out of the nets end sadly: numerous tentacles always find a small strip of exposed skin, even on a person dressed in a marine robe.
How the bell burns Nomura and his brothers
Jellyfish are slow and clumsy, and it is difficult for them to hold on to their caught prey. So you have to act with paralyzing poison, grow stinging cells with a coiled harpoon thread inside. When a crustacean or fish touches a tiny protrusion near such a cell, the thread instantly shoots out, pierces the side and injects poison.
Jellyfish toxins have been little studied, but it has been established that one of their components is histamine, which is responsible for a severe allergic reaction. Other substances in the poison affect nervous system, paralyzing planktonic fines and causing severe pain in marine mammals and man.
Third place: Chrysaora – a gentle and fiery beauty
Chrysaora has chosen the eastern and western shelves of the North American continent. Its dome reaches a meter in diameter and is sand-colored with dark radial stripes. 24 thin stinging tentacles up to 5 m long hang from the edges of the dome. Around the mouth, located on the underside of the dome, 4 more tentacles grow, lush, like a feather boa. All together it resembles a lady's hat with ribbons.
The second name of the underwater beauty is sea nettle. Like the plant of the same name, chrysaora burns sharply and painfully, but not for long. Within an hour, the burning and itching stop, and the next day the redness goes away.
How chrysaors migrate
There is an opinion that jellyfish swim only with the flow. However, they easily move wherever they want, collecting water under the dome and throwing it out with strong pushes. This method of movement is called reactive.
Chrysaors make multi-day sea voyages in search of prey: comb jellyfish and plankton. Sometimes they gather in clusters of tens of thousands of individuals - zoologists call this phenomenon a “swarm” or “bloom”. Why chrysaors behave this way remains to be studied.
Fourth place: purple striped jellyfish
This rare creature lives off the coast of California. The diameter of its bell reaches 70 cm, the length of its thin marginal tentacles is 2 m. In its youth, the jellyfish is colorless, it is decorated with barely visible dark stripes and an edging along the edge of the dome. As they age, the stripes turn bright brown, and the jellyfish itself takes on a rich blueberry color.
The burns caused by the purple striped jellyfish are not fatal, but unpleasant, like a lash. In 2012, 130 beachgoers on Monterey Bay were injured after encountering a large group of young, and therefore difficult to see, animals in the water.
Why is the body of a jellyfish transparent?
The jellyfish does not have a single internal organ. Their flesh consists of two rows of cells, between them there is a thick layer of gelatinous substance, which is 98% water. The jellyfish seems to be made of liquid glass.
Cells share all the work of the body among themselves. Some produce toxins, others digest prey, and others are responsible for sensitivity. There are cells whose responsibilities include the prompt restoration of body parts bitten off by turtles and other predators. But since there are only two layers of cells, the general outlines of objects can be seen through the jellyfish.
Fifth place: Black Sea Cornerot
For the Mediterranean and Black Seas, this is the largest representative of jellyfish. The diameter of the bell reaches 60 cm, weight – 10 kg. Kornerot does not have the long hunting tentacles characteristic of Chrysaora or Cyanea. There are small oral lobes that resemble young roots of well-fed seedlings.
Cornerotes are hardly noticeable, since on their transparent, colorless body there is only one colored area - the purple edging of the dome. Bathers discover the jellyfish when they touch the floating jelly. For most people, this animal is safe, and only severe allergy sufferers react to its soft touch with a scattering of hives.
Can a jellyfish feel?
Sight, hearing, taste - this is not about jellyfish. The nervous system is too primitive. However, sailors have long noticed that before a storm, cornermouths disappear, moving away from the shore.
It turned out that along the edges of the dome the animals carry tubes with lime crystals. In response to infrasounds that appear in the sea 10-15 hours before the storm, the crystals begin to move and touch microscopic sensitive tubercles.
The signal about this is received by nerve cells. Now sailors are armed with the “jellyfish ear” device, which notifies in advance of the approach of bad weather.
The world's largest jellyfish, the cyanea jellyfish, and its smaller sisters are some of the most beautiful inhabitants of the ocean. They have been dancing slowly and mysteriously in the salt water for hundreds of millions of years. During this time, they acquired delicate colors, burning poisons and the finest hearing. But zoologists are sure that not all the secrets of transparent beauties have been revealed.
“Crystal meat” is how Chinese residents figuratively and poetically call jellyfish.
In China and South Korea, if a fish restaurant does not have jellyfish dishes on its menu, this does not give it the right to receive the highest category.
Jellyfish fishing is developed mainly in countries South-East Asia: China, Japan, Korea, Thailand, Malaysia, Indonesia and the Philippines. Among the edible jellyfish in these countries, the most popular are Rhopilema and Aurelia. The cost of one ton of salted jellyfish can reach 5-8 thousand US dollars.
In China, where jellyfish have long been considered a favorite delicacy, the mouth blades of captured jellyfish are separated and the umbrella is washed until completely removed. internal organs from mucus. Thus, essentially only the jelly-like mass of the umbrella goes into further processing. There is a very complex - from 3 to 6 stages - and long - from 20 to 40 days - procedure for soaking jellyfish umbrellas in a mixed solution of table salt and alum (or juice and leaves of tanning plant species). The dehydrated and hardened product - “crystal meat” - is subsequently used to prepare a wide variety of dishes. Salted jellyfish are added to salads, and also eaten boiled and fried, seasoned with pepper, cinnamon and nutmeg. Jellyfish itself is tasteless, so it is advisable to add various spices when cooking.
In Japan, where jellyfish is also considered a delicacy, the product undergoes no less thorough processing. The jellyfish umbrella is separated from the tentacles, dried and salted, and the salted jellyfish is desalinated immediately before cooking.
Jellyfish is extremely healthy; it contains various vitamins and minerals (manganese, iron, chromium, copper, 17 amino acids). The Japanese believe that jellyfish promote longevity. The Chinese call jellyfish “crystal meat”; they treat tracheitis and regulate blood pressure.
Jellyfish are placed in salads and desserts, made into sushi and rolls, and even used in hot dishes. In total, several dozen culinary masterpieces are created from jellyfish in China and Japan. The main conditions for a successful dish are a professional chef and a fresh product. Frozen jellyfish is absolutely impossible - after defrosting, it turns into a nasty slimy slurry. Therefore, jellyfish are not exported, and it is impossible to taste this delicacy far from its habitat.
Source otvet mail ru
In the cuisine of some eastern peoples, jellyfish fried in oil is an everyday dish. The bluish-green jellyfish, the bell of which reaches 60-70 cm, is quite suitable for use as food. In the waters of southern Primorye it is found in large quantities in June-August. You can catch it with nets. When processing jellyfish, they usually use an umbrella bell - a substance that resembles dense jelly, sometimes fleshy appendages similar in appearance to cauliflower. The jellyfish bell is thoroughly washed in sea water and then placed on clean sheets of plywood and dried in the sun.
Jellyfish can be first salted and then dried in the sun.
Dried jellyfish contains more than 10% protein, fat and other useful substances.
Here is an example of one of the popular Chinese salads. The jellyfish is soaked in water, salted in concentrated brine, and after three weeks it is removed and washed, but the main thing is not to damage the fragile “body.” Then it is again soaked in water for a quarter of an hour and dipped in boiling water for 10-15 seconds - again time is very important, an extra 3 seconds - and the tender “meat” turns into old rubber. The finished jellyfish is cut into strips, mixed with shrimp, garlic, soy sauce and sesame oil. The Japanese marinate jellyfish, and then also cut them into strips and mix them with stewed vegetables and herbs, and they are also added to fruit jellies and marmalades.
Source lifecity com ua
Jellyfish are very amazing creatures that evoke an extraordinary attitude towards them. Jellyfish can be found in every sea, in every ocean, on the surface of the water or at a depth of many kilometers.
Jellyfish are the oldest animals on the planet, their history goes back at least 600 million years. There is an incredible number of different species in nature, but even now the emergence of new ones, previously unknown to scientists, is being recorded.
Jellyfish (Polypomedusae) are one of the phases life cycle cnidarians Medusozoa, which are usually divided into three types: hydroid, scyphoid and box jellyfish. Jellyfish reproduce sexually. There are males who produce sperm and females who produce eggs. As a result of their fusion, the so-called planula is formed - a jellyfish larva. The planula settles to the bottom, where over time it turns into a polyp (asexual generation of jellyfish). Having reached full maturity, the polyp begins to bud off a young generation of jellyfish, often completely different from the adults. U scyphoid jellyfish the newly separated specimen is called ether.
The body of jellyfish is a jelly-like dome, which, through contractions, allows them to move in the water column. Tentacles equipped with stinging cells (cnidocytes) with a burning poison are designed for hunting and capturing prey.
The term "jellyfish" was first used by Carl Linnaeus in 1752, as an allusion to the animal's resemblance to the head of the Gorgon Medusa. Becoming popular around 1796, the name began to be used to identify other medusoid species of animals, such as ctenophores.
A little interesting facts about jellyfish:
The world's largest jellyfish can reach up to 2.5 meters in diameter and have tentacles more than 40 meters long.
Jellyfish are capable of reproducing both sexually and by budding and fission.
The Australian wasp jellyfish is the most dangerous poisonous animal in the world's oceans. The venom of a sea wasp is enough to kill 60 people.
Even after the death of a jellyfish, its tentacles can sting for more than two weeks.
Jellyfish do not stop growing throughout their lives.
Large concentrations of jellyfish are called “swarms” or “blooms.”
Some species of jellyfish are eaten in East Asia, considered a “delicacy.”
Jellyfish don't have a brain respiratory system, circulatory, nervous and excretory systems.
The rainy season significantly reduces the number of jellyfish living in salt water bodies.
Some female jellyfish can produce up to 45,000 larvae (planulae) per day.
Pink jellyfish from the Scyphozoan family was discovered quite recently, a little over 10 years ago, in the waters of the Gulf of Mexico and the Caribbean. Some individuals of this species reach up to 70 cm in diameter. Pink jellyfish can cause serious and painful burns, especially if a swimmer inadvertently ends up among a large concentration of these creatures.
Antarctic Diplulmaris- one of the species of jellyfish of the Ulmaridae family. This jellyfish was recently discovered in Antarctica, in the waters of the continental shelf. The Antarctic Diplulmaris is only 4 cm in diameter.
Flower cap jellyfish(lat. Olindias Formosa) is one of the types of hydroid jellyfish from the order Limnomedusae. Basically, these cute creatures live off the southern coast of Japan. Feature- motionless hovering near the bottom in shallow water. The diameter of the “flower cap” usually does not exceed 7.5 cm. The tentacles of the jellyfish are located not only along the edge of the dome, but also over its entire surface, which is not at all typical for other species. A flower cap burn is not fatal, but is quite painful and can lead to severe allergic reactions.
Purple striped jellyfish(lat. Chrysaora Colorata) from the class Scyphozoa is found only near the coast of California. This rather large jellyfish reaches 70 cm in diameter, the length of the tentacles is about 5 meters. A characteristic feature is the striped pattern on the dome. In adults it has a bright purple color, in juveniles it is pink. Purple-striped jellyfish usually live alone or in small groups, unlike most other species of jellyfish, which often form huge colonies. The Chrysaora Colorata burn is quite painful, but not fatal to humans.
Giant Nomura jellyfish(Latin: Nemopilema nomurai) is a species of scyphoid jellyfish from the order Cornerotae. This species predominantly inhabits the East China and Yellow Seas. The size of individuals of this species is truly impressive! They can reach up to 2 meters in diameter and weigh about 200 kg. The name of the species was given in honor of Mr. Kan'ichi Nomura, director general of fisheries in Fukui Prefecture. In early 1921, Mr. Nomura first collected and studied a previously unknown species of jellyfish. Currently, the number of Nomura jellyfish in the world is growing. Possible reasons population growth, scientists believe climate change, overexploitation water resources and pollution environment. In 2009, a 10-ton fishing trawler capsized in Tokyo Bay with three crew members trying to remove nets overflowing with dozens of Nomura jellyfish.
Tiburonia granrojo- a little-studied species of jellyfish from the Ulmáridos family, discovered by MBARI (Monterey Bay Aquarium Research Institute) only in 2003. It lives at depths between 600 and 1500 meters in Hawaii, the Gulf of California and Japan. Thanks to its rich dark red color, this species of jellyfish has earned the nickname Big Red. The big red jellyfish is one of the most large species jellyfish, its diameter ranges from 60 to 90 cm. Currently, only 23 individuals of this red giant have been found and studied.
Pacific sea nettle(lat. Chrysaora fuscescens) - has a bright characteristic golden-brown color, due to which it is often kept in captivity (aquariums and oceanariums). The name of the jellyfish genus Chrysaora goes back to Greek mythology. Chrysaor is the son of Poseidon and Medusa the Gorgon; his name translated means “he who has golden weapons.” IN wildlife Sea nettles are found in the Pacific Ocean from Canada to Mexico. The diameter of the jellyfish's dome can reach more than 1 meter, but more often no more than 50 cm, the length of the tentacles is 3-4 meters. The tentacles of the jellyfish are very thin, so the burn looks like a bright red welt, similar to a blow from a whip. Although victims experience severe pain and burning, going to a medical facility is usually not required. You can neutralize the effects of jellyfish toxins and relieve pain with vinegar or citric acid.
Portuguese man of war(lat. Physalia physalis) is a bright and very toxic representative of colonial hydroids from the order of siphonophores. It is most common in tropical and subtropical regions of the Pacific and Indian Oceans and the North Atlantic Ocean. Recently, there has been a significant increase in the number of this species. Since 1989, physalia has appeared in the Mediterranean Sea, for the first time off the coast of Africa, then Corsica, and in 2010 it was discovered off the coast of Malta. In the period 2009-2010, cases of physalia appearing off the coasts of Ireland and Florida were recorded. Entire flotillas of Portuguese man-of-war can now be found off the coast of Guyana, Colombia, Jamaica, Venezuela, Australia and New Zealand. In fact, the Portuguese man-of-war is not a single jellyfish, since it is a whole colony of polypoid and medusoid individuals united under one “roof”. The tentacles of this unusual organism, when extended, can reach up to 50 meters in length. A Man of Portugal burn is comparable in toxicity to a poisonous snake bite. For burns, it is necessary to treat the affected area with 3-5% vinegar in order to prevent the release of poison from the stinging cells remaining in the wound. Only in rare cases do physalia burns lead to death. The Man of Portugal is especially dangerous for children, the elderly and allergy sufferers. Be extremely careful with this type of jellyfish.
Cephea cephea or the so-called “soft” jellyfish is widespread throughout the Indo-Pacific region, including the Red Sea. This large jellyfish can reach up to 50 cm in diameter.
Aurelia eared(lat. Aurelia aurita) is a scyphoid jellyfish from the order of discomedusae. Widely distributed in the coastal waters of tropical and temperate seas. In particular, the Mediterranean and Black Seas. The diameter of the aurelia dome can reach up to 40 cm. The color is pinkish-violet, the body is almost transparent. Until recently, this type of jellyfish was not considered dangerous to humans. However, there have been several recent cases of severe burns in the Gulf of Mexico. It is believed that in the waters of the Black Sea, aurelia does not pose a serious danger to humans.
Australian jellyfish or sea wasp (lat. Chironex fleckeri) from the class of box jellyfish - the most dangerous deadly animal in the world's oceans. The main habitats are the coasts of northern Australia and Indonesia. The sea wasp is one of the largest species of box jellyfish; the diameter of its dome can reach up to 20-30 cm. Its pale blue color and almost complete transparency make it especially dangerous for swimmers, since it is not easy to notice in the water. The tentacles of a jellyfish are densely covered with stinging cells containing extremely strong poison. Burns caused by box jellyfish cause severe excruciating pain and in some cases can lead to rapid death. Sea wasp venom simultaneously affects the heart, nervous system and skin. Moreover, the neurotoxic venom of a jellyfish acts much faster than the venom of any snake or spider. Cases have been recorded where death occurred within 4 minutes of contact. First aid for a sea wasp burn consists of immediately treating the affected area with vinegar, removing tentacles stuck to the skin (remove only with protected hands or tweezers!) and immediate treatment medical institution, as administration of antitoxic serum may be required. The Australian jellyfish is the most dangerous jellyfish in the world!
Ctenophores(Latin Ctenophora) are jellyfish-like organisms that live in sea waters almost all over the world. Distinctive feature of all ctenophores - a kind of “combs”, groups of fins-cilia, used by this species for swimming. The sizes of Ctenophora range from a few millimeters to 1.5 meters. Among ctenophores, there are many deep-sea species capable of bioluminescence.
Aequorea Victoria or "crystal" jellyfish - a bioluminescent jellyfish from the order of hydromedusae. Widely distributed along the North American western Pacific coast, from the Bering Sea to Southern California.
Australian spotted jellyfish(lat. Phyllorhiza punctata) belongs to the family of pelagic jellyfish. Its main habitat is the southern Pacific Ocean. The usual size of the dome of the spotted Australian jellyfish is up to 40 cm, but in the waters of the Persian and Mexican Gulfs it reaches 70 cm. The Australian jellyfish is not dangerous to humans. However, to neutralize the poison, you should resort to a proven method - treat the skin with vinegar or citric acid in order to prevent possible allergic reactions. Recently, a massive proliferation of Australian jellyfish has been recorded, which can pose a serious threat to commercial fish populations. Feeding on eggs and fry, they pass up to 15,000 liters of water per day through their tentacles and swallow huge amounts of plankton and other marine life.
Mediterranean jellyfish Cassiopeia can reach up to 30 cm in diameter. Spends most of its time in shallow water, basking in the sun's rays.
Hairy cyanea or Lion's mane jellyfish (lat. Cyanea capillata, Cyanea arctica) is a large jellyfish from the order of disc jellyfish. The species is distributed in all northern seas of the Pacific and Atlantic oceans, living near the coast in surface layers of water. The bell of the Arctic cyanea (a subspecies of the hairy cyanea) can reach up to 2 meters in diameter, and the length of the tentacles is up to 33 meters. Lion's mane is generally considered a moderately stinging jellyfish. The burns it inflicts are quite painful, and the toxins contained in the poison can cause a severe allergic reaction. However, the poison of this jellyfish is not fatal to humans.
Jellyfish Chrysaora Achlyos- one of the largest species of scyphoid jellyfish. The bell size is approximately 1 m in diameter, the tentacles can reach up to 6 m in length. It has the ability of a chameleon - changing color from bright red to black.
A new species of transparent jellyfish discovered in Antarctica. Its diameter is about 2.5 cm
Jellyfish feeding
A predatory jellyfish captures food with its tentacles and digests it in the body cavity with the help of enzymes in the digestive cells.
Movement of jellyfish:
The movement of jellyfish is carried out by “stepping” and “tumbling”.
Irritability
Irritability is produced due to nerve cells, scattered throughout the body.
Meaning:
· Consumed as food
Some jellyfish are deadly and poisonous to humans. For example, when bitten by a cornet, significant burns can occur. When bitten by a cross, the activity of all systems of the human body is disrupted. The first encounter with a cross is not dangerous, the second is fraught with consequences due to the development of anophiloxia. The bite of a tropical jellyfish is fatal, but the bite of an ordinary jellyfish goes away in 3 days and does not have any consequences.
Jellyfish help fight stress! In Japan, jellyfish are bred in aquariums. The smooth, leisurely movements of jellyfish calm people, although keeping jellyfish is very troublesome and expensive.
The first robotic jellyfish appeared in Japan. Unlike real jellyfish, they not only swim smoothly and beautifully, but if the owner wishes, they can “dance” to music.
A certain type of jellyfish is caught off the coast of China and eaten! Their tentacles are removed, and the “carcasses” are kept in a special marinade, which turns the jellyfish into a translucent cake of delicate thin cartilage. In the form of such cakes, jellyfish are brought to Japan, where they are carefully selected for size, color and quality. For one of the salads, the jellyfish cake is cut into thin strips about 3-4 mm wide, mixed with stewed vegetables and herbs and poured with sauce.
Jellyfish go through quite a long development path. Fertilized eggs develop into larvae that float freely in the water. These larvae then attach to the seabed and grow into polyps. As a result of division, small jellyfish can bud from the polyp. They grow to adult size and reproduce. This process is called "alternation of generations." Almost all jellyfish live in seawater. However, there are also several freshwater species. In Europe it is freshwater jellyfish Craspedakusta with a diameter of only 2 cm, living in ponds and shallow lakes. Now it has become a rarity.
Jellyfish can be round like a ball, flat like a plate, elongated like a transparent airship, very small, like a sea wasp, and huge, like the giant of the Arctic waters, the fiery red lion's mane, whose domed body grows up to two and a half meters in height. diameter, and bundles of wriggling thread-like tentacles, reaching 30 m in length, can cover a five-story building.
Much more modest in size, the pelagia jellyfish, or nocturnal jellyfish, amazes experienced sailors bright light in the middle of the night in the waters of the Mediterranean Sea.
Not everyone knows that the beauty of most types of jellyfish can be very deceptive. After all, to a greater or lesser extent, all jellyfish are poisonous. The only difference is that some species are practically not dangerous to humans, others sting like nettles, and a painful burning sensation can be felt for several days, and others cause paralysis that can lead to death.
There are also jellyfish that are completely harmless to humans. This is the well-known glassy-white “eared” jellyfish - Aurelia. It lives in all tropical and moderately warm seas, including here in the Black Sea. These are summer animals. Autumn storms bring death to them, so they have adapted, so to speak, to “put off” their offspring for the winter. On the eve of cold weather, small, slightly more than a centimeter, lumps of living tissue, carriers of the Aurelia genetic code, settle to the bottom of the sea. They are not afraid of storms or cold snaps, and with the arrival of spring, tiny discs separate from them, which grow into adults in one summer.
By the way, if you rub the body of Aurelia into human skin, it becomes immune to “stinging” jellyfish, such as, for example, the same Black Sea rosistoma, otherwise known as corneros.
The most dangerous of all existing jellyfish are sea wasps. They are found in the warm waters of the Indian and Pacific Oceans. It's hard to believe that this little blob of living mucus is actually a real killer. And meeting him is almost more dangerous than meeting a shark. The venom of the sea wasp is so strong that if it enters the bloodstream, it can stop a person’s heart in a few minutes. In search of food, such as bottom-dwelling shrimp, these deadly creatures sometimes come very close to the shore. And as a result, in the coastal waters of Australia, the poison of these little killers last years More than fifty people died.
The largest existing jellyfish is the giant Arctic jellyfish, whose umbrella reaches 2.2 m in diameter; its tentacles are 35 m long. As we see, jellyfish can be gigantic! This giantess, as well as many other jellyfish, paralyze their prey with stinging cells. This poison can be very painful and even dangerous for humans. So some caution will not hurt if you come across a jellyfish with long threads in the sea. On the other hand, you don’t need to think that touching every jellyfish can cause a burn.
Speaking about jellyfish, one cannot help but recall their closest relatives - siphonophores, or, as they are also called, Portuguese man-of-war. The elongated bodies of these animals, similar to air bubbles, sway above the water and in appearance really resemble caravels under sail. Thanks to the obliquely placed comb on its float, the siphonophore goes “in full sail”, always remaining at an acute angle to the wind. And behind it, like a trail, stretch very long (up to 15 meters) and very poisonous tentacles.
The main difference between the Portuguese man-of-war and a jellyfish is that it is not one creature, but a whole community of completely different individuals, each of which has its own task - some control the movement, others catch prey, others paralyze it, and others digest and divide nutrients with all members of the colony.
During the voyage, the Portuguese warship is accompanied by its own “retinue”. These are small nomei fish that hide from predators under reliable protection long tentacles. The poison of the stinging cells of the boats does not affect the nimble escorts.
Jellyfish can be dangerous not only for people, but also for ships. Ship engines are cooled by sea water, which enters through a special hole in the bottom. And if jellyfish get into this hole, they tightly shut off the water supply. The engine overheats and fails until divers clear the live plug.
The hairy cyanea jellyfish, caught in the northwestern part of the Atlantic in 1865, is listed in the Guinness Book of Records. Its cap was 2.28 meters across and its tentacles extended 36.5 meters. That is, if you stretch the tentacles in different directions, the length of such a jellyfish will be 75 meters. This is the longest animal on Earth!
Black Sea jellyfish are the oldest jelly-like organisms without a skeleton or tissue base. They are found only in salt water of varying saturation, they move chaotically, unconsciously. The existence of jellyfish cannot be attributed to any of the evolving categories. In the 650 million years since their appearance, these transparent gelatinous animals have not changed one iota.
Anatomy
The body of a jellyfish is extremely primitive: among the internal organs it has only a stomach, which is connected to the mouth. There is no hole for removing waste; the animal also pushes out all waste food through the mouth. The stomach of most species of jellyfish is used for movement in space. It works on the principle of a jet nozzle, contracting, pushing out the collected water and thereby creating thrust, due to which movement occurs.
Varieties
In total, thousands of species of jellyfish live in the Earth's reservoirs, seas and oceans. Some live in colonies in the form of huge clusters, slowly migrating with the current or under the influence of the wind. Others are, as a rule, quite large specimens, live separately, hunt alone, but do not have housing. Jellyfish do not have a settling reflex, and they never stay in one place.
Stinging jellyfish in the Black Sea are not numerous, there are only three species: Cornerot, Aurelia and Mnemiopsis. These animals have been well studied, but belong to the category of individuals that are under constant observation by scientists.
Population distribution
The largest Black Sea jellyfish is the rhizostoma pulmo. The diameter of its round body can reach half a meter. Cornerot is a well-recognized animal; its difference from other species is the absence of tentacles. Instead, massive branches up to a meter long extend from the dome. Each has spongy thickenings.
How is a corner mouth constructed?
The dome, or umbrella, of the jellyfish is milky white, round, spherical shape, along the edge there is a purple fringed border. Hanging from under the dome are eight fleshy roots with soft growths in which poisonous stinging threads are hidden. When touched by someone else, the jellyfish shoots out stinging arrows and can cause unpleasant sensations similar to a nettle sting. The poison is weak, its effect wears off within a few days.
Cornerot feeds on small fish, sea worms, and small crustaceans. It paralyzes its prey with poison and then eats it. This type of jellyfish is the largest population in the Black Sea. And although there is no benefit from these animals, it is the cornet that has a unique ability, for which Black Sea fishermen value it. This jellyfish is a living barometer; it is sensitive to weather changes; on the eve of a storm, it moves away from the shore and goes into the depths.
However, not all marine protozoa have such abilities. Other jellyfish of the Black Sea, Aurelia and Mnemiopsis, do not feel the approach of bad weather, remain on the surface and die in the thousands. These two species are less numerous, but their numbers are also significant. Habitat - mainly in shallow water, along the coast of Crimea, around the city of Sudak, the village of Planerskoye and all the way to Kerch. Both species are capable of movement, but their migration is chaotic.
Black Sea jellyfish have long been studied by scientists for their migration. Over many years of observations, only one conclusion was made: there is no pattern in the movements of gelatinous creatures. They are completely left to the elements and resemble autumn leaves: wherever the wind blows, they float. Scientists tried to draw a logical chain, linking the migration of jellyfish with the prevailing winds. However, the jellyfish of the Black Sea did not live up to expectations even in this matter; they simply never strive anywhere. If there is no wind, they stand still; if the wind blows, they move.
Aurelia
Another large jellyfish that lives in the Black Sea is the Aurelia. The diameter of its umbrella, or dome, is about forty centimeters, the body is translucent, usually colorless, but sometimes turns pink, blue or purple tint. At the top of the dome four circles are visible, arranged symmetrically. These are the gonads. Poisonous jellyfish of the Black Sea are unisexual creatures; they fertilize themselves when it is time to reproduce.
Aurelia, or sherikh, as it is also called by fishermen who fish in the Black Sea, feeds on small crustaceans, larvae, and diatoms. Having caught the prey, the jellyfish lulls it with poison and, after the victim is immobilized, slowly eats it. Aurelia lives in the coastal zone, in shallow water, does not swim far into the sea and does not dive to depth. This format of existence is explained by the fact that the jellyfish is afraid of the cold, its living space is limited to warm water.
At the same time, this species is very tenacious. Jellyfish are thermophilic, but can withstand sub-zero temperatures without dying. Such abilities are observed in many invertebrate animals; some tolerate cooling while moving, others fall into suspended animation.
Mnemiopsis
The jellyfish is relatively small in size, up to ten centimeters, and lacks tentacles and stings. It is distinguished by the ability of biological luminescence, that is, it glows in the dark. Once born, Mnemiopsis develops quickly, sexual maturity of both male and female individuals occurs no later than two weeks from the date of birth. The process of fertilization is not fundamental; the jellyfish is capable of self-reproduction. The embryo is formed within twenty hours.
Mnemiopsis feeds only on zooplankton, sometimes eating the eggs of small fish, sprat, sprat, and capelin. The jellyfish is distinguished by the absence of a satiety reflex; it always eats. If the gastric space is completely filled, the excess is discarded and the process continues. At the same time, in the absence of food, a jellyfish can live from two to three weeks.
Mnemiopsis was introduced into the Black Sea from the eastern shores of America by chance, in the holds of ships plying along trade routes. Its appearance in the Black Sea caused significant damage to fishing. Today, measures are being taken to reduce the population of this jellyfish.
Should you be wary of gelatinous organisms?
Whether jellyfish in the Black Sea are dangerous or whether there is no reason for concern is a question that has been studied for a long time. There is still no definite answer. There is, of course, poison in the stinging tentacles of Black Sea jellyfish, but it is weak and can cause a sting like nettle, but no more. However, there were cases when people who suffered from contact with a jellyfish near the coast of Crimea lost consciousness from severe toxic poisoning. In such a situation, the answer to the question of whether jellyfish are dangerous in the Black Sea should be in the affirmative. Therefore, the conclusions of toxicology scientists are still vague, research continues.
So, the question is “Jellyfish in the Black Sea are dangerous or not?” remains open for now. In places where they gather, it is recommended to be careful and touch their umbrellas, and especially their tentacles, as little as possible. In addition, every bather must know which jellyfish in the Black Sea sting and which are absolutely harmless. This information will help you avoid being bitten by a harmless animal unless provoked.
When do jellyfish appear in the Black Sea?
Invertebrates, especially marine ones, have their own “resort season” when they are most comfortable in their native element, warm and have plenty of food. For Black Sea jellyfish, these are three months of the year: July, August and September. At this time, they actively reproduce, swim to the best of their ability, and a person should not disturb harmless creatures during this period; it is better to let them live their lives. The time when jellyfish appear in the Black Sea is not precisely defined, the time is different every year, but approximately it is the end of June - the beginning of July.
