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What kind of water do jellyfish swim in? Jellyfish facts: poisonous, luminous, the largest jellyfish in the world. Jellyfish in the Black Sea

Pollution of coastal waters, fishing, and a host of other factors have led to the fact that coastal waters There are more jellyfish in general, and extremely dangerous ones for humans in particular.

Today there is no such beach (Thailand, Spain, Türkiye, Maldives, Hawaii, etc.) where a tourist would not encounter poisonous jellyfish. And if you are not an expert in marine fauna, then it is unlikely that at one glance you will be able to distinguish the degree of danger that a jellyfish poses. Therefore, remember once and for all:

ALL JELLYFISHES ARE DANGEROUS!

Jellyfish do not have a brain, instead of a brain they have a network of nerve cells and their entire existence is based on the usual reflexes of feeding, reproduction and self-defense. Within the framework of these principles of life, they exist, because their behavior is predictable - they often move in schools, they swim near the surface, they are found in masses of plankton, they can be thrown ashore by a storm, they will not touch you unless you become a threat to them.

Is it possible to avoid meeting a jellyfish?

It is impossible to completely prevent such a meeting, but there are several techniques that will reduce the risk of a meeting to the level of an unpredictable accident:

Jellyfish feed on plankton, fish eggs and other small things, so at night, when the water cools, they come closer to the shore in search of food. The same reasons apply when it rains.

In general, the possibility of encountering some kind of nasty thing in the dark night and muddy rainwater is simply colossal. Therefore, think three times whether the pleasure of night or rain bathing is worth the risk that is associated with it.

2. Purple flag!!!

The movement of jellyfish is monitored by specially trained teams, who report the presence of jellyfish in the beach area to rescue services, lifeguards, police, and local traders. They, in turn, raise a purple flag in prominent places and rescue booths.

For tourists, messages about the danger of the presence of jellyfish are also posted on boards on the beaches, so checking the beach for the presence of warning boards will not be amiss. If there is no shield or flag, ask the nearest rescuer or merchant how the situation with jellyfish is:

Tell me, is the jellyfish in the water? [pliz, tel mi, is se jellyfish in se vote?]

If the answer is “Yes!”, then you still shouldn’t get into the water or be very careful.

3. You cannot swim in unequipped places!!!

If there is no lifeguard on the beach, then:

You will not see a warning that you are in danger;

In the event of an accident, you may be denied payment for your insurance;

You may not be saved because there will be no one to save you!

4. Behavior of local residents!!!

A clear indicator of the possibility of swimming on a public beach - local residents who splash in the water next to tourists - they know better than anyone the nature of their country and the time when the beach is safe. If locals wander along the beach and don’t get close to the water, then you should wait too.

5. Jellyfish season!!!

Each beach has a season known as "jellyfish season". Try to find out about the jellyfish season before choosing a tour so that you don’t get an unpleasant surprise when you only have access to the pool. For example, in Sardinia in the summer there is only 1(!) week of the season when the beaches are clear of jellyfish.

6. Do not touch the jellyfish that lie on the beach!!!

Jellyfish washed ashore are no less dangerous than jellyfish in the water - for another 3 days after the death of a jellyfish, its stings are toxic. Notify rescuers or police about the find - the jellyfish will be removed immediately.

There are families of jellyfish that swim extremely fast or almost instantly shoot out tentacles or shoot stinging cells towards danger. Your touch is a danger and the jellyfish will definitely react to it. Therefore, for those who snorkel or scuba dive, the main rule is to stay as far as possible from any jellyfish, especially giant ones. No spectacular shot is worth the risk of getting a fatal burn.

8. You shouldn’t rely on a suit, but it’s preferable to swim in clothes!!!

Yes, Crocs on your feet, breeches instead of swimming trunks, a T-shirt and, oddly enough, women's tights can prevent or reduce the level of burns, at least if they are quickly removed, you can avoid touching the threads of tentacles that stick to the victim and penetrate the skin .

Yes, a 3 mm thick neoprene diver's suit is almost impenetrable to jellyfish.

But! Even in a diver's suit there are areas where the body is exposed - either there are no gloves, or socks are missing, or there is an area near the mask. Remember that sometimes all it takes is a momentary contact for a big toxic blow.

9. Use waterproof lotion!!!

Of course, this will not protect you from all jellyfish, but the lotion is very effective against some. The lotion can be purchased at any pharmacy near the beach. It is applied an hour before swimming. Helps protect not only from jellyfish, but also from water lice, algae and other unpleasant sensations. The trick with the lotion is that it not only protects you from... solar radiation, but actually masks secretions from your skin that may be attractive to jellyfish. The lotion costs around $15, and it seems that this is not the highest price for protection.

10. Dive only with a mask!!!

Try to swim without the water touching your face. And diving is only with a mask. This simple technique will protect the particularly sensitive area around the eyes and a significant part of the face.

Good day, dear readers!

Surely many of us, on these hot August days, have already been or are still going to the sea, and some to the ocean, and this is wonderful. In general, rest is a wonderful thing, just like swimming. But there are representatives of the fauna in this world who can ruin your mood with their behavior. And one of these God's creations is jellyfish.

Anyone who has not been burned by a jellyfish is lucky, although burns come in varying degrees. However, there are cases when a jellyfish sting is so strong that a person, in addition to first aid, also needs further treatment.

Today's article will be about jellyfish - the most poisonous types of jellyfish and what to do if they sting a person.

What is a jellyfish?

Jellyfish– represents one of the phases life cycle Cnidarians (aquatic multicellular animals). The body of a jellyfish is 98% water and is shaped like an umbrella. Thanks to the structure, mainly from connective tissue, the reactive movement of a jellyfish is produced by contracting its muscles and cap. The weight of a jellyfish can range from tens of grams to several hundred kilograms, and the diameter of the cap can reach more than a meter; however, despite its size, the localization and movement of jellyfish directly depends on the current.

The food of jellyfish is zooplankton, however, some types of jellyfish are themselves used in cooking. Also, these slimy-watery creatures can serve as food for various fish, for example, adult tuna.

Some types of jellyfish are dangerous to humans. The fact is that jellyfish are not only a kind of “cleaners”, but also predators. The tentacles of the jellyfish contain stinging cells that contain poison used for hunting. Depending on the type of jellyfish, contact with human skin can cause a burn, an allergic reaction, and possibly even anaphylactic shock and death.

Jellyfish in the Black Sea can rarely cause complications such as anaphylactic shock; they are more likely to leave allergic redness, pain, burning, and itching on human skin. Jellyfish in the Mediterranean Sea and ocean waters are more dangerous - contact with them can result not only in anaphylactic shock, but also paralysis of the nervous system, suffocation and death.

In fact, if you are bitten by a jellyfish, the symptoms and consequences largely depend on the person’s primary health condition, his predisposition to allergic reactions, the type of jellyfish and the duration of contact with it.

Types of jellyfish

Jellyfish in the Black Sea:

Aurelia (lat. Aurelia)- low-hazard representatives of jellyfish that practically do not sting humans.

Cornerots (lat. Rhizostomeae)– this species has a characteristic purple color and can leave a burn on contact. Depending on the location, the burn may go away painlessly within a few minutes, or, conversely, leave redness that requires treatment. medical care. This is due to the fact that in some places the skin is more delicate. In children, a jellyfish sting can trigger the development of an allergic reaction.

The most dangerous and poisonous jellyfish in the world:

Box jellyfish (lat. Cubozoa)- the most dangerous and poisonous class of jellyfish, consisting of about 20 species living in tropical and warm seas With oceanic salinity. It is characterized by a rectangular bell (cap), on the edges of which there are tentacles.

If we talk about more specific poisonous jellyfish, we can highlight the following:

sea ​​wasp(Chironex fleckeri)- the largest and poisonous species box jellyfish, living in the waters of Australia, Indonesia and Oceania, mainly in shallow waters. The venom of one “sea wasp” can cause the death of up to 60 men. The size of the bell can reach 40 cm in diameter, but due to its pale blue, almost transparent color, it is very difficult to notice in sea waters. Each of the corners of the bell has 6 eyes and one bunch of 15 tentacles, completely covered with poisonous stinging cells (nematocytes). The size of the tentacles during swimming is about 15 cm in length and about 5 mm in thickness, however, during its hunting, the tentacles can stretch up to 3 m in length. An interesting point is that Chironex fleckeri is food for sea ​​turtle, which are not affected by their poison.

The burn of the Sea Wasp jellyfish causes severe excruciating pain, and the poison can kill a person within 3 minutes, which is why some scientists consider it the most dangerous representative fauna in the world.

Irukandji (Alatina mordens, Alatina moseri, Carukia barnesi, Carukia shinju, Malo kingi, etc.)- a species of box jellyfish, a resident of sea waters mainly in Australia and Oceania. Irukandji is a small but very poisonous jellyfish - a transparent whitish bell adult has a size of only about 12 * 25 mm, from which 4 thin, almost imperceptible tentacles emerge, up to 1 m long.

Irukandji is characterized by approachable, almost imperceptible bites, which a person does not always pay attention to and therefore does not always consult a doctor in a timely manner. At this time, the poison spreads throughout the body, causing the so-called. Irukandji syndrome, which is accompanied by symptoms of intoxication (nausea, vomiting), pain in the back, abdomen and pelvis, disruption of the nervous system (severe, dizziness, excessive sweating, paralysis), increased tachycardia and possibly pulmonary edema. Deaths small, but there is enough chance of becoming disabled. As a preventative measure, small nets are stretched on Australian beaches to prevent holidaymakers from being bitten.

Physalia (Portuguese man-of-war)– extraordinary beautiful representative jellyfish, the cap of which is similar to a dome, painted in different colors. Natural habitat habitats are the waters of the Mediterranean Sea, as well as the Indian and Pacific oceans. As in the case of Irukandji, a physalia bite is not very painful and is not always noticed by a person, but at this time the poison enters the blood and, along with its current, spreads throughout the body, causing symptoms in the victim such as convulsions, dizziness, malfunction respiratory organs and paralysis. Taken together, such symptoms contribute to the possibility of the victim drowning.

Cyanea (lat. Cyanea arctica, Cyanea capillata) - a type of scyphoid jellyfish that lives in Northern waters Atlantic and Pacific oceans, closer to the surface. Cyanea is one of the most large species jellyfish in the world. Its cap in most cases reaches a diameter of 60 cm, however, there are individuals, especially the Arctic cyanea, whose bell can reach more than 2 m, and elongated tentacles 36.5 m! The color of cyanide varies, but with a predominance of reddish-yellowish and brown shades.
The consequences of a cyanea bite, despite its size, are predominantly allergic reactions, pain, nausea, general malaise, and swelling of the mucous membranes.

Cross jellyfish (gonionema, lat. Gonionemus vertens)- poisonous hydromedusa, swimming mainly in the shallow waters of the Northern part Pacific Ocean, from California (USA) to China, as well as the Western part Atlantic Ocean. Crusaders especially love to swim in thickets of zostera (sea grass). The diameter of the transparent bell with a cross pattern is only 25-40 mm. The color of the crosspiece is given by painted internal organs– gonads. At the edges of the cap there are about 60 thin tentacles with thickenings consisting of stinging poisonous cells.

A jellyfish sting is not life-threatening in normal health, but the burn is extremely painful.

Important! Remember, a jellyfish lying on the shore can also sting, so avoid all contact with it!

Jellyfish sting - symptoms

The main symptoms of a jellyfish sting:

  • – the main symptom of a jellyfish sting on the Black Sea, accompanied by pain, a burning sensation, and the appearance of a red spot ();
  • Sharp pain, which may intensify as the poison spreads, causing general pain;
  • Rash - the formation of small red rashes at the site of the bite, which can then be filled with liquid;
  • Formation of blisters, sometimes with bruising;
  • Symptoms of intoxication develop when poison spreads throughout the body and are accompanied by loss of appetite and malaise.

Complications from a jellyfish sting

  • Severe pain syndrome;
  • Severe headache, loss of consciousness;
  • Convulsions, paralysis;
  • Lethal outcome.

Important! For symptoms of anaphylactic shock (swelling of the tongue, convulsions, spontaneous urination and defecation, hyperemia or panic), call immediately ambulance or take the person to a medical facility, otherwise he may die suddenly.

If stung by a jellyfish, with obvious symptoms, the victim should be given first aid, and, if necessary, further treatment.

If you are stung by a jellyfish - first aid

1. Get out of the water. If you feel slight pain, you need to get out of the water, because... further bathing and wasted time may enhance the final result of the bite. The fact is that in water the consequences of a bite are not so noticeable or perceptible, but the poison still acts at this time and continues to affect the skin, and then seep into circulatory system, spreading throughout the body. Moreover, swimming is physical activity, in which blood circulation is faster than at rest, which is why the jellyfish venom can spread throughout the body much faster. But that’s not all - after a bite, a severe allergic reaction may occur, convulsions and dizziness may appear, so if you do not get out of the water, there is a risk of drowning.

2. Remove any remaining jellyfish from the surface of the skin. This is due to the fact that in its tentacles, as we have already said, there are poisonous stinging cells, and if they are not scraped off, an additional portion of poison may enter the body. Just remember to touch bare hands tentacles are not allowed, use a third-party object for this purpose.

3. Neutralize the poison. Immediately after the bite, apply something cold to this area, which will slow down the absorption of the poison into the blood and its further spread throughout the body. And as soon as you have an antiseptic at hand ( salt water, hydrogen peroxide, “Chlorhexidine”, etc.), treat the bite site with it.

4. Reduce swelling and neutralize the allergic reaction (if any). To reduce swelling and relieve an allergic reaction, take an antihistamine - “Diazolin”, “”, “”, “”. Additionally, to relieve swelling, apply a cool compress to the affected area; you can treat the skin locally with a corticosteroid-based ointment (hormonal ointment). If you have a severe allergic reaction or the onset of anaphylactic shock, read:

5. Remove any remaining poison from the body. For this purpose, a cloth soaked in a soda solution can be applied to the affected skin area. apple cider vinegar or ammonia. Very effective means is a soda paste with added salt, which is applied to the wound and removed after drying. For symptoms of nausea and dizziness, take a sorbent, for example Atoxil. It is also recommended to drink plenty of fluids, preferably with added sugar - sweet tea, compote.

6. Rest. First aid for a jellyfish sting is carried out while the victim is at rest, preferably in the shade.

Treatment of jellyfish burn

For removal prevention or removal inflammatory process(redness, swelling, blistering and other signs of a burn), itching of the bite site can be treated with anti-inflammatory drugs - Afloderm, Bepanten, Dermovate, Panthenol, Trimistin.

Important! If the symptoms after first aid do not bring the desired result within 1-2 weeks, or symptoms of intoxication of the body appear (dizziness, nausea, vomiting), it is necessary to continue treatment, so consult a doctor.

To relieve an allergic reaction, “Diprospan”, “Citrine”, “Trexil”, “Fenistil”, “Eden” are used.

In case of a severe allergic reaction (Quincke's edema, anaphylaxis - with symptoms of suffocation, swelling of the tongue, larynx), "Medopred", "Dexamethasone",

For muscle spasms, together with antihistamines, you can give an injection with an antispasmodic drug - “No-Shpa”.

What not to do after a jellyfish sting

1. Treat the wound with running water;

2. Treat the wound with brilliant green or iodine, since they can only increase the size of the site of inflammation;

3. Treat the wound with oil (butter or sunscreen, it doesn’t matter), alcohol or alcoholic beverages;

4. Drink alcoholic beverages during treatment;

5. Rub or scratch the bite area with a dry cloth;

6. Leave the burn exposed to sunlight.

Preventing jellyfish sting

Preventing a jellyfish sting includes following the following safety rules:

  • Avoid contact with jellyfish, especially their tentacles, especially jellyfish that have a certain color - purple, blue, brown and others;
  • If there are tentacles of a jellyfish lying on the shore or swimming in the sea, do not touch it, because... its surface is covered with a large number of poisonous cells, which can be active even separately from the main body;
  • Swim in the sea on specially equipped beaches, especially in the seas and oceans of the tropical regions of the Earth where swimming greatest number poisonous jellyfish;
  • If you are a diving enthusiast, try to avoid contact with residents seabed, which may resemble corals or various bushes, because they may be a form of jellyfish.

Many of those who vacationed at sea encountered jellyfish. This helped to realize the fact that they cannot be called ordinary and harmless creatures. Let's look at some interesting facts about jellyfish.

What does science know about jellyfish?

Researchers believe that jellyfish have been around for about 650 million years. They are found in all layers of each ocean. Various live in both salt and fresh water. Their primitive nervous system, which is located on the epidermis, allows you to perceive only smells and light. The nerve networks of jellyfish help them detect another organism through touch. These "animal plants" essentially do not have a brain or sensory organs. They do not have a developed respiratory system, and breathe through thin skin, which absorbs oxygen directly from the water.

While exploring interesting facts about jellyfish, scientists noticed that these creatures are able to positively influence people experiencing stress. For example, in Japan they breed jellyfish in special aquariums. Their smooth and measured movements act as a sedative. Although such pleasure is expensive and causes additional troubles, in general it is justified.

Jellyfish are more than 90 percent water. The venom from their tentacles is used as a raw material for drugs that regulate blood pressure and to treat respiratory diseases.

It was called the “Portuguese man-of-war” by some 18th-century sailors who liked to tell others about the jellyfish floating like a Portuguese warship of the Middle Ages. In fact, her body is very similar to this vessel.

Her official name- physalia, but this is not one organism. It's about about a colony of jellyfish and polyps in different modifications, which interact very closely, and therefore look like one creature. The poison of some species of physalia is deadly to humans. Most often, the habitats of the Portuguese man-of-war are limited to the subtropical parts of the Indian and Pacific Oceans, as well as the northern bays of the Atlantic Ocean. In more rare cases, they are carried away by currents into the waters of the Caribbean and Mediterranean seas, to the shores of France and Great Britain, to the Hawaiian Islands and the Japanese archipelago.

These jellyfish often swim in huge groups of several thousand individuals in warm waters. The transparent and shiny jellyfish body rises above the water by about 15 centimeters and moves along a chaotic trajectory regardless of the wind. Those individuals that swim near the shore are often thrown onto land by powerful winds. IN warm time year, the physalia swims away from the shore, it moves with the current towards one of the earth's poles.

Distinctive features of physalia

Other interesting facts about this type of jellyfish concern their unique features. Physalia is one of two biological species, capable of glowing red. The Portuguese warship also uses its air bag filled with nitrogen, carbon dioxide and oxygen as a sail. If a storm approaches, the jellyfish releases its bubble and goes under water. Small perches like to swim near its tentacles; they do not sense a toxic environment and have serious protection from enemies, as well as food particles. Perches attract other fish with their appearance, which become food for these invertebrates. This is such a symbiosis.

There are a considerable number of species known today as physalia. In the Mediterranean Sea alone, researchers have discovered about 20 species of Portuguese man-of-war.

Physalia jellyfish, interesting facts about reproduction

It is not known exactly how this jellyfish reproduces. However scientific research showed that they reproduce asexually, and in each colony there are polyps that are responsible for reproduction. In fact, they are the ones who create new colonies. Portuguese man-of-war They differ in that they can reproduce continuously, which is why the number of nascent jellyfish in the waters of the oceans and seas is growing.

Another common version of the reproduction of physalia indicates that, when dying, the jellyfish leaves behind some organisms that exhibit sexual characteristics, after which new individuals are formed. This theory has not yet been proven.

About the tentacles of the Portuguese man-of-war

Regarding the jellyfish tentacles, the interesting facts are that their structure is unique. The “limbs” of jellyfish are equipped with a large number of capsules containing poison, the composition of which is similar to the poisonous substance of a cobra. Each of these small capsules is a hollow, twisted tube with fine hairs. If contact occurs between the tentacles and the fish, the fish will die due to the stinging mechanism. When a person receives a burn from this jellyfish, he experiences sharp pain, develops a feverish state, and has difficulty breathing.

The interesting facts about jellyfish don’t end there. The tentacles of these invertebrates can reach 30 meters in length. In addition, a person who is engaged in swimming, enjoying the process itself, will not always be able to see a bright blue-red bubble on the water and realize the danger that threatens him.

Irukandji jellyfish: interesting facts about the danger posed by it

This small jellyfish, which lives off the coast of Australia, produces toxic substances that act stronger than poison cobras There are 10 types of Irukandji, 3 of which are deadly. The bite is almost imperceptible, but its consequences are a powerful heart attack, which in some cases can result painful death. And all this can happen in just 20 minutes. Because these invertebrates are so small and practically invisible, they can easily penetrate any barrier network that is designed to big creatures posing a danger to swimmers and vacationers.

There are some other interesting facts about this species of jellyfish. Since fishermen often fell ill with a strange disease after each trip to the sea, they realized that the reason for this was contact with some kind of sea creature. The jellyfish was named after the Irukandji tribe. Over time, thanks to Dr. Barnes, it was finally possible to establish that the cause of the disease was contact with jellyfish. Although its size is quite small, its tentacles reach a length of 1 meter. The pain from the bite is so severe that it forces you to double over, is accompanied by severe sweating and vomiting, and your legs tremble violently.

Conclusions

Although these invertebrate organisms are difficult to see in the water, regardless of their size, you still shouldn’t be careless and inattentive while swimming in the sea or walking along the shore - for the sake of your health. Many types for human health and life.

However, they also do useful features in their habitats, they are used in medicine as raw materials for drugs. And who knows, maybe humanity will be able to get even more benefits from jellyfish.

Photo: Brandon Bourdages/Rusmediabank.ru

In the summer, many people go on vacation to the sea and have the opportunity to meet jellyfish with their own eyes.

I saw them for the first time when our train was transported on a ferry across.

The flat cakes, which were huge in my opinion, swayed nearby on the waves, sometimes they fell under the propellers and flew apart. I felt sorry for them.

There were no them in the sea near the beaches of Evpatoria that year. But on next year There was a whole invasion of jellyfish in Gurzuf. True, they were small. And fortunately, Black Sea jellyfish are not poisonous.

The most amazing thing is that our enterprising people have found use for this seemingly absolutely useless sea ​​creatures. Women caught jellyfish and put them on their feet, thus they treated the bumps on their feet. True, I have not heard of anyone being cured.

They appeared in the world a long time ago; scientists believe that their history goes back at least 600 million years.

Their shapeless appearance with tentacles, apparently, did not predispose ancient people to a friendly perception, so they called these animals jellyfish in honor of the mythical ancient Greek goddess, who was called Medusa the Gorgon. Instead of hair, this “charming lady” had hair moving on her head. poisonous snakes, and jellyfish have tentacles.

The term “jellyfish” was first used in 1752 by Carl Linnaeus.

And starting in 1796, this name began to be used to identify other medusoid species of animals.

Jellyfish, Latin Medusozoa, is an invertebrate marine animal, a lower multicellular creature that belongs to the type of coelenterates.

Among them there are not only free-swimming ones - jellyfish, but also sessile ones - polyps and attached forms - hydra.

We are interested in the jellyfish. By appearance it resembles an umbrella or a bell.

A jellyfish has no brain, circulatory, nervous or excretory systems. She breathes with her whole body. Its body is gelatinous, transparent, has no skeleton and is 98% water.

When a jellyfish is in water, due to its transparency, it is invisible.

Almost all jellyfish living in cold seas white. But the jellyfish are warm tropical seas They are colored bright pink, green, blue, red, yellow, sometimes the color of these jellyfish looks like a pattern.

Jellyfish have tentacles along the edges. They can be short, long, sparse, dense. There may be only four or several hundred.

On the tentacles of jellyfish and on other parts of the body there are stinging cells that secrete poison. This poison can be weak and insignificant, or it can be strong and cause burns or even be fatal.

When thrown ashore, the jellyfish cannot reach the water on its own and dries up.

The British called the jellyfish “jelly fish.”

The tissues of the jellyfish body consist of ectoderm and endoderm, they are connected to each other by an adhesive substance - mesoglea.

Each layer has its own function.
The ectoderm is like “skin” and nerve endings; it is responsible for movement and reproduction.
And the endoderm is responsible for digestive processes.

The hole located in the lower part, in the middle, surrounded by tentacles, serves as a mouth.

The mouth of different types of jellyfish can vary greatly in structure. It may look like a long tube, a proboscis, and there may be lobes or tiny tentacles along its edges. Undigested food remains are excreted through the same hole.

The jellyfish has no eyes, but along the edge of the umbrella there are special organs with the help of which it distinguishes day from night and determines where is up and where is down.

Jellyfish can be small - from 1-2 cm, tiny, 2 mm in diameter and large - up to 2 meters. And the tentacles of giants can reach 35-40 meters in length.

The weight of such giants can reach up to a ton. Interestingly, jellyfish can grow throughout their lives.

Some jellyfish can glow in the dark, glowing red, while those that swim close to the surface of the water glow blue. This phenomenon is called bioluminescence.

Scientists explain that the glow occurs during the decay of a special substance called phosphor.

The number of jellyfish living in salty waters decreases with the beginning of the rainy season.

And there are jellyfish in salty seas all over the world.
They are sometimes found in brackish lakes coral islands and in enclosed lagoons that were once part of the sea.

The only one freshwater species The jellyfish is considered to be the tiny jellyfish Craspedacusta, which lives in the Amazon.

Sometimes jellyfish migrate in search of food and are carried over long distances by currents. Thin muscle fibers in the umbrella they help the movement of the jellyfish a little with their contractions. In this case, the jellyfish always move in the direction opposite to the mouth. Although they can swim in different directions - up, down, horizontally. In a relaxed state, jellyfish sink to the bottom.

Even the largest jellyfish are unable to withstand sea currents.

Jellyfish are considered solitary animals because they do not communicate with each other.

Although in places rich in food, large concentrations of jellyfish can be observed. Sometimes they fill the entire water space.

The jellyfish is a predatory animal; it captures food with its tentacles, swallows it whole and digests it with the help of enzymes in the digestive cells.

Depending on their type and size, the diet of jellyfish includes: plankton, small crustaceans, fish fry, small fish, fish caviar, smaller jellyfish, just small edible pieces of someone else's prey.

Jellyfish reproduce by budding or transverse division.

But most Jellyfish reproduce sexually. Male and female jellyfish are no different in appearance.

Male jellyfish produce sperm, female jellyfish produce eggs, the reproductive cells of jellyfish mature at any time of the year, eggs and sperm are released into the water through the same mouth, after their fusion a larva is formed - a planula, which is unable to feed or reproduce.

After swimming a little, it settles to the bottom and attaches itself to it. From the planula grows an asexual creature - a polyp. When the polyp reaches maturity, new larvae, similar to small stars, form from it by budding. They swim in the water until they grow up and become jellyfish.

In some species of jellyfish there is no polyp stage; in them, new individuals are formed directly from the planula.

And in jellyfish species such as bougainvillea and campanularia, polyps form directly in the gonads of adult individuals. And the jellyfish, as it were, gives birth to small jellyfish of its own species.

Jellyfish reproduce very quickly; females can produce up to 45,000 larvae - planulae - per day.

Therefore, they quickly restore their population numbers both after the rainy season and after any climate changes.

live different types jellyfish from several months to two years.

All vacationers on the seas need to know that there are jellyfish that are very dangerous to humans. The stinging cells of some types of jellyfish cause serious burns. The poison of some of them does not lose its lethality, even if the jellyfish itself is no longer alive.

The most dangerous of the jellyfish is the “Australian wasp”, which lives in the waters of Australia. This animal has enough poison to kill 60 people.


No less dangerous is the jellyfish from the Pacific Ocean - the Irukandji jellyfish.


People often at first do not attach importance to the bite of this jellyfish due to the fact that it is small, only about 12 cm in diameter, and its bite is almost painless, but the poison begins to act quickly.

Pink jellyfish cause serious and painful burns. It is especially dangerous to be among a cluster of these jellyfish.


Burn of a beautiful "flower cap" jellyfish that lives in shallow waters near south coast Japan may cause a severe allergic reaction.

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There are other types of jellyfish whose bite is not fatal, but very unpleasant.

Therefore you can't touch unknown species, both living and dead jellyfish.

If it was not possible to avoid a burn, then you need to get out of the water as soon as possible and rinse the bite area with plenty of fresh water and consult a doctor who will give the necessary injection.

Recovery after a bite can last 5-7 days.

Some types of fish are also enemies of jellyfish.

The fry of some fish live under the umbrella of a jellyfish, and as they grow up, they gradually eat it.

Some jellyfish were used as a medicinal remedy in ancient times and in the Middle Ages. For example, diuretics and laxatives were made from cornet. Medicines are now made from the venom of some jellyfish to reduce blood pressure and treatment of lung diseases.

And in China and Japan, some species of jellyfish are used in cooking, although jellyfish do not have any nutritional value.

In nature, jellyfish cleanse sea ​​waters from small organic waste, but if there are too many of them, they can clog the water settling tanks in desalination plants.

It's no secret that large number jellyfish can pollute beaches.

Interestingly, there are jellyfish lovers who keep them in aquariums at home.

Jellyfish need clean salt water, so a powerful water purification system is needed. Plus, jellyfish need good lighting.

At home, as a rule, they keep moon jellyfish and cassiopeia jellyfish, which do not exceed 30 cm in diameter. But you need to take into account that although these jellyfish are not life-threatening, their burns can be sensitive.

Jellyfish are fed with live food, which is purchased in specialized stores.

You cannot put fish in the same aquarium with jellyfish; only motionless animals are suitable as neighbors.

The good news is that you can swim in the Black Sea absolutely calmly, as it dangerous jellyfish they just don't exist.