Why are jellyfish dangerous? How dangerous are jellyfish for humans: how to protect yourself from being burned by a sea animal
The sea jellyfish, which is called a wasp, belongs to the category of box jellyfish, a type of cnidarians. She is a representative of the exceptional animals of the marine world and is able to live only in the salt water of the seas and oceans.
Invisible danger
The sea wasp jellyfish is considered the most poisonous jellyfish in the world. The toxin that is released from its tentacles depresses nervous system, causes severe burns and unbearable pain. The result is a heart attack that can lead to cardiac arrest. Timely rendered medical care in some cases it can save a person’s life. However, there are known cases of death within a very short period of time after an encounter with a poisonous monster. Even a dead sea wasp (photo below) is a source of increased danger. The poison-toxin disintegrates only a week after the death of the jellyfish, so it is strictly forbidden to touch it.
Unfortunately, jellyfish of this species are also found in places beach resorts and diving sites. Another danger of meeting a sea wasp is that it is almost invisible. Therefore, precautions should not be neglected.
Habitat
The jellyfish is found in the Indo-Western Pacific Ocean and in Southeast Asia. Most often, the sea wasp is found near the coast of northern Australia, where there are many corals and shallow sea depths. summer months from November to March. Jellyfish inhabit coastal areas at a respectful distance from the coast, but when the sea is very rough they can be washed ashore.
Appearance
The sea wasp is the most major representative of his class. The body of the jellyfish is a transparent dome, consisting of 95% water. Its shape is similar to a rounded cube, hence the name box jellyfish. The size of the dome is 20-45 cm, in size it can be compared with a basketball ball. It has a pale blue color and is completely invisible in the water.
The animal has 24 eyes, which are located in three pairs in each corner of the dome. Two pairs of eyes serve to receive images, and one only reacts to light. Scientists cannot explain the presence of so many eyes in a jellyfish, because the information received from what it sees has nowhere to be transmitted; it does not have a brain.
In addition to the organs of vision, there are 60 tentacles - four bundles of 15 pieces each. The probes, 15 cm long and 5 mm thick, stretch up to three meters when hunting for prey. Each tentacle is covered with stinging cells containing deadly poison.
The sea wasp does not have a skeleton; it is replaced by two nervous systems, one of which receives and processes information received from the organs of vision, and the other controls the movement of muscles along the border of the dome, which function simultaneously and harmoniously.
Nutrition
Sea wasps feed in coastal waters small fish and various bottom organisms, but the most favorite delicacy are shrimp. When going out to fish, they extend their tentacles and freeze in place. The jellyfish encloses the stalked victim in probes, pierces the skin, injects poison, kills and swallows. In appearance, its bite resembles a wasp, only the venom is much more toxic, incomparable even to the venom of a snake.
Reproduction
The sea wasp gives birth only once in its entire life, and then dies. Box jellyfish live for about 7 months and continue to grow throughout this period.
Sea wasps reproduce offspring in the same way as other individuals belonging to this species. They reproduce in summer period, gathering in large flocks and swimming closer to the shores. During this period of time, Australia is trying to close all beaches.
The male ejects a dose of sperm into the water while near the swimming female. The latter swallows it, fertilization occurs. Larvae develop inside the female, which after some time are released into the water and settle on the surface of the seabed. They stick to stones, shells, and driftwood, forming polyps.
As a result of budding, small jellyfish grow from polyps, which break off and begin an independent life. They immediately navigate the sea and feed on plankton on their own.
What do Australians call a sea wasp?
Due to its transparency, this small sea animal is almost invisible in the water. Is an active predator and represents great danger for animals and humans. This animal swims well and maneuvers well among algae and corals, moving at speeds of up to six meters per minute. During the day it is most often at the bottom, and with the onset of evening it floats to the upper layers of the water. The speed at which a jellyfish attacks its prey is very high.
And the poison contained in the tentacles is so poisonous that when stung, any creature instantly dies. Moreover, it stings several times in a row, bringing the concentration of poison to a lethal level. Australian sea wasp - that’s what this jellyfish is called - it poses a danger to all living organisms, with the exception of the poison of these predators does not affect them, and turtles eat box jellyfish with appetite.
Consequences of an encounter with a sea wasp
Box jellyfish, although extremely dangerous to human life, do not attack them themselves; on the contrary, they tend to swim to the side. It can sting a person purely by accident. Often the victims are scuba divers who are not protected by special suits.
When the skin comes into contact with the tentacle, terrible pain, severe redness and swelling appear. A person's heart most often stops and he drowns. Some managed to get ashore, but paralysis set in respiratory system, and the man died. After autopsies, it was discovered that the victims' respiratory organs were filled with mucus, while others died from cerebral hemorrhage. There were cases where a person did not die immediately, but no one remained alive.
Protecting the lives of vacationers
During the jellyfish migration season, net barriers are installed on beaches to prevent them from entering the swimming area. Despite this, small specimens penetrate through the mesh cells, so the beach administration warns vacationers about the danger and strictly prohibits them from entering the water.
This warning should not be ignored. After all, the fast-acting poison of the sea wasp leaves no hope of salvation. The only way to help is to administer an antidote - antitoxic serum and urgently hospitalize the victim. But this does not give any guarantee of saving life.
- It is known that jellyfish appeared more than 600 million years ago, much earlier than dinosaurs, crocodiles and sharks.
- Jellyfish and polyps - different stages life period the same creature.
- A sea wasp is a jellyfish that breathes through its entire dome and stings like a wasp.
- The absence of a brain does not prevent them from perceiving nervous stimulation from the organs of touch and vision.
- They have two nervous systems.
Jellyfish are able to move underwater by sucking in and expelling water by contracting their parasol muscles, but they mostly drift thanks to the current. Scientists believe that they belong to plankton.
Evgeny Marushevsky
freelancer, constantly traveling around the world
It's ridiculous to turn down an exotic vacation after learning that there will be wasps. But if we're talking about about the sea wasp, then quickly change your tickets to another direction!
We are not talking about an annoying striped insect or another flying creature similar to it that lives near sea shores. A wasp “swimming” in sea waters (sea wasp) is the most poisonous jellyfish in the world. That's what people called it dangerous creature, which has its official name - Chironex fleckeri. It belongs to the class of box jellyfish, a species of marine cnidarians. Its distribution areas are considered to be waters off the coast. Northern Australia and Indonesia.
In general, these inhabitants of the seas and oceans are 95% water. They lack a brain, but at the same time they have effective weapon. Most "jellyfish" have stinging cells that can release a deadly sting. The interesting thing is that before this, the pressure inside them reaches 136 atmospheres! After this, the cell cracks and the toxin flies out at a speed that far exceeds the flight of a bullet. This phenomenon is considered one of the most fast movements in nature.
The sea box (its second “alias”) has earned its fame for its ability to inflict painful and fatal burns: long tentacles sea creature covered with nematocytes - stinging cells containing poison. A translucent creature of “innocent blueness” is capable of destroying sixty people in three minutes! Observations over the last hundred years report a similar number of human deaths from a rendezvous with a sea wasp.
In its "jellyfish society", Chironex fleckeri is considered one of the largest. Its dome is the size of a basketball, and its translucent blue body makes it inconspicuous in the water column. This adds danger to anyone who wants to splash around in the sea.
It has four bundles of tentacles, fifteen in each. When this dangerous beauty swims, they contract and are no more than 15 centimeters in length. But when it’s time to hunt, the tentacles become thinner and grow up to three meters!
Like other representatives of the box jellyfish class, the box jellyfish has light-sensitive devices that are equipped with two dozen eyes (our heroine has 24). To today It is not known whether these “eyes” are capable of tracking an object and forming images, because jellyfish completely lack a central nervous system. Scientists have differing opinions on this matter.
The sea wasp menu consists of small fish and shrimp. But the poisonous creature itself can go for lunch as the main course. sea turtles- the only animals that are absolutely not vulnerable to the venom of the blue jellyfish, and it is part of their diet.
The most terrible burns of Chironex fleckeri can cause instant death, since its poison instantly affects the nervous system and skin. The pain that appears immediately after contact with its tentacles is so strong and painful that it can lead to death from painful shock. But for a burn to cause trouble of this nature, the amount of poison must be truly impressive. This is considered contact with three meters of tentacles of a box jellyfish.
The poison works quickly! History knows of cases of death from a sea wasp burn that occurred in no more than four minutes. Note that this is much faster than the tragic consequences of a snake or poisonous insect bite.
Despite the deplorable picture, there is an antidote to this jellyfish. But, unfortunately, it is often difficult to help a victim who is far away. Such a swimmer does not have time to swim to the shore or boat and dies from heart attack. But if you managed to help pull the victim out of the water, then immediate remedy- This is vinegar that can neutralize nematocysts that do not have time to react. It is strictly forbidden to rub the bite site or pour water or other liquids on it, which will provoke the release of toxic substances.
If dangerous meeting occurred, then it is important to remove the tentacles that wrap around his body from the victim. This should be done carefully, using rubber gloves or tweezers. It may surprise you, but even remote tentacles carry serious danger to a person. And that's not all! Their dried fragments are restored with the slightest moisture. It is known that ordinary table vinegar can slightly neutralize the effect of “jellyfish” poison.
In the practice of treating bites Australian snakes They use a simple technique to prevent the dangerous distribution of poison through the vessels: rigid fixation of the affected limb with a bandage. The same method cannot be used in cases of burns from box jellyfish, since bandaging only helps the nematocysts. It is very important to introduce a special serum on time.
Despite the fact that warning signs are installed in places where poisonous jellyfish may appear, “brave” tourists often ignore such signs. The authorities have thought of an opportunity to let vacationers splash around in sea water: Public beaches have perimeter nets.
The five most poisonous jellyfish in the world
The Miroscope tries to “open the eyes” of those inexperienced tourists who believe that the water is the best scary beast- shark. The translucent cute jellyfish, as you have already found out, can be much more dangerous if you let your guard down.
So, you are familiar with the sea wasp (aka the boll wasp). Fortunately, it’s in absentia :) But she’s not the only one on the list that travel lovers need to know. Let's continue our acquaintance!
Number two - irukandji
Her abode is water areas Pacific Ocean in the area of Australia. However, sudden warming on our planet allowed scientists to make a disappointing forecast: the jellyfish appeared in the World Ocean and its spread there continues.
A small “umbrella” no more than 25 mm in diameter has four meter-long tentacles dotted with stinging cells. If the box jellyfish shoots out its poison throughout the entire cell, then the irukandji sprays it only with the tip of its tentacle. Some bathers do not even pay attention to the mini-burn, but the poison begins to act slowly, gradually intensifying. Within an hour the person becomes ill: terrible pain in the body, including internal organs, headache. Nausea appears, blood pressure rises, and pulmonary edema begins. In rare cases, death may occur.
How to help the victim? Immediately treating the burn site with vinegar will help somewhat relieve the effect of the poison. In a medical institution, the patient’s life is saved by supporting him with special medications until the poison leaves the body on its own. Unfortunately, no antidote has been found for Irukandji.
It must be remembered that the nets that help prevent sea wasp visits on beaches will not protect you from small irukandji at all.
Number three is physalia. She is also “The Portuguese Man of War”
Despite the fact that this type of jellyfish prefers tropical waters, its accumulations are sometimes observed off the coast of France and Great Britain. During real invasions of physalia, many Spanish and Italian beaches are closed. The beaches of Thailand also suffer from “ships”.
This strange creature(in fact, it does not belong to jellyfish) - a real colony amazing organisms of four polyps: a gas bubble that rises above the surface of the water, and others hiding under the water and responsible for different purposes. The length of the defensive tentacles can reach 50 meters!
The venom of the tentacles rarely causes death, but the pain caused by its contact with the skin is excruciating. In addition, other symptoms arise: body temperature rises, it becomes difficult for a person to breathe and stay afloat. Traces remain on the skin - bright stripes-burns that will remain for life in the form of scars. Fesalia, which washed ashore sea wave, remains dangerous for a long time.
While the sea wasp is very easy to miss in the water, the “boat” is clearly visible on the surface due to its bright color. IN dark time days, colonies of these marine organisms are capable of creating a beautiful glow.
Number "four" - cross jellyfish
Yours unusual name this jellyfish received a clear cross located on its body. It is formed by internal organs, which are clearly visible through its colorless umbrella. The largest specimens of the cross do not reach more than four centimeters in diameter ( medium size- 25−30 mm). Along the edges of the transparent dome there are from six to nine dozen thin tentacles. When expanded, their thickness exceeds the body thickness of the jellyfish by five to seven times. Jellyfish are often called “clinging” jellyfish because their tentacles are covered with suckers.
The beauty can be found in the eastern waters of the Pacific and Atlantic. It began to be observed more and more often in Primorye. She prefers sea thickets, where the water is perfectly heated and is not crystal clear.
Unwanted contact with a cross will not lead to death, but will be remembered for a long time by painful sensations. The surprising thing is that repeated burns can already lead to death.
If a swimmer is burned, they should immediately get out of the water and seek help from a doctor. Within half an hour (and sometimes even earlier) after meeting the tentacles of the cross jellyfish, symptoms appear: limbs go numb, pain seizes the lower back, breathing becomes difficult, nausea and constantly want to drink. The poison can continue its effect for up to 4 days until it leaves the body.
Number “five” - giant cyanea (hairy cyanea, “lion’s mane”)
Meet the largest jellyfish: the diameter of its dome exceeds two meters and the length of the tentacles is up to thirty-seven meters!
The giant's habitat is cold or moderately cold waters ( northern seas Atlantic and Pacific Oceans, Arctic seas). You can also meet it off the Australian coast. IN warm waters she is not comfortable and even once she gets there, she is not able to grow more than 50 centimeters.
Her appearance depends on the size. Thus, small specimens of these jellyfish are yellow-brown or orange in color. More impressive cyanens have inclusions of brown, scarlet and purple colors.
Why is it called "lion's mane"? Look at the photo. Numerous tentacles resemble the tangled mane of the king of beasts. But stinging cells are unknown to this predator, which cannot be said about its marine “double”.
Cyanea tentacles contain a strong poison, but not fatal to humans (only one death has been recorded in the world). Contact with jellyfish is dangerous due to an allergic reaction, which is accompanied by a painful rash on the body.
Of course, you didn't intend to swim in the company of jellyfish. But, as they say, God protects those who are careful!
The sea wasp is descended from the cnidarian class of Box jellyfish. This animal is considered quite rare and the most dangerous jellyfish in the world for humans. IN water spaces There are many types of jellyfish in the oceans and seas. But, by rights, the most poisonous is the sea wasp.
The jellyfish got its name because it stings exactly like an ordinary wasp, only the poison is sea beast much stronger. If it gets into a living organism, then there is practically no chance of salvation. If a diver accidentally collides with a school sea jellyfish, he may no longer come ashore.
What is a sea wasp?
In the vastness of the ocean you can find large number the most dangerous and diverse animals that have not been fully studied. One of them is the sea wasp. It belongs to the class of box jellyfish. The peculiarity of this predator is that it is almost impossible to see. A sea jellyfish sneaks up unnoticed and stings the creature it comes across. People called this beast “invisible death.”
Those who saw the sea jellyfish did not speak of this creature as a monster. Compared to their cousins, these jellyfish are relatively small size. In their shape, they resemble a cube. On average, body diameter does not exceed 5 centimeters. There are individuals the dome of which reaches 25 centimeters. But such a specimen can be found extremely rarely.
The weapons of the most poisonous jellyfish in the world are its tentacles. Average length the tentacles are one and a half meters long. Their maximum quantity can reach 60 pieces. If a sea wasp clasps its victim with all its limbs, then death cannot be avoided. With the help of special glands in each limb, a very strong poison is produced. At the sea wasp the venom is many times stronger than that of a snake.
Another feature of this sea creature that everyone still can’t figure out is world scientists, is why the most poisonous jellyfish needs eyes if it does not have a brain. Can she see?
Based on research results, it is known that this sea animal actually has there are eyes. There are as many as twenty-four of them. The visual organs are divided into 4 groups. Each group has 6 eyes.
Sea wasp jellyfish habitat
Most people believe that jellyfish can live in absolutely any body of water. But this statement is erroneous. The only habitat of the sea wasp is Australia. Marine inhabitants prefer to choose their habitat northern shores, whose waters are relatively shallow and contain a lot of corals.
Lifestyle of the most poisonous jellyfish
It's no secret that the most dangerous jellyfish in the world is a very active and aggressive hunter. The sea wasp hunts while still. As soon as the victim touches its invisible limbs, a powerful stream of poison immediately penetrates the prey. It is worth noting that the jellyfish attacks its prey several times. Thus, the victim dies much faster. The venom of this predator is considered very strong. It affects the nervous system and affects the heart and skin.
Its diet includes small fish and crabs. Having stung the prey, the jellyfish uses its tentacles to pull it towards its cone, where the victim is calmly digested.
The main place for food production is in coastal zones. When not hunting, predators stay away from the shore. It often happens that as a result strong storm, these animals are washed ashore where large cluster people.
Reproduction
Reproduction occurs in the sea wasp, as in all representatives of this family. First of all, eggs are laid, from which small larvae emerge. Immediately after their appearance, they stick to the bottom, forming a single polyp. Polyps reproduce by budding.
Once the small jellyfish has broken away from the polyp, it is ready to independent life and immediately goes in search of food. Because the sea beast that was born left the polyp, it withers and suddenly dies.
Does a sea wasp attack humans?
Poisonous jellyfish presents great danger for humanity. However, she uses only what she can eat as her main hunting object. Humans are not included in the sea wasp's food list. Having met a person, the jellyfish tries to swim away. It stings a person only if a collision is inevitable. Divers mainly encounter this bite.
After the animal has been stung several times, the body receives huge amount poison.
The effect of poison on the body manifests itself in several stages:
- redness of the stung area of skin;
- the burn site begins to swell;
- dizziness;
- high fever;
- cardiac arrest is possible.
Death can occur instantly or after two days. It all depends on how much poison the jellyfish injected into the body.
This predator swims very quickly. Due to its speed, the poisonous jellyfish can maneuver perfectly between corals. This predator can only be detected at shallow depths. Sea wasps usually lead night look life. During the day they hide at the bottom, but as soon as the sun begins to set, they float to the surface.
Reminder for tourists
When going on vacation to a place where there is a high risk of encountering these predators, tourists should adhere to some tips:
- It is worth knowing that when meeting a jellyfish, it must be carefully circumvented. Its tentacles are capable of extending over quite a long distance.
- Diving on greater depth, better refrain from touching anything with your hands.
- It is not recommended to go into the water after a storm. There is a high probability of contact with fragments of a tentacle.
If you still meet with aquatic inhabitant took place, then:
- thoroughly rinse the bite area a large number salt water;
- treat the wound with vinegar or strong alcoholic drink;
- very carefully remove the remaining tentacles from the wound.
After the procedures have been performed, you must urgently seek help from qualified medical personnel.
Jellyfish are the oldest sea creatures, which appeared hundreds of millions of years ago. These are their names underwater inhabitants received because of the similarity with mythical creature- Medusa Gorgon. The body of these animal representatives sea world more than 90% consists of water. Their favorite place habitats are salt waters. Translucent creatures are the object of research by scientists. Call special interest poisonous and largest jellyfish.
10. Irukandji jellyfish 10 centimeters
- one of the most poisonous Pacific jellyfish. The main habitat is Australian waters. The diameter of its dome is about 10 centimeters. Irukandji has four tentacles, the length of which can reach 1 meter. A jellyfish sting is dangerous to humans and can cause a number of unpleasant consequences: pain throughout the body, nausea, vomiting, tachycardia and even pulmonary edema. In rare cases, death may occur. Irukaji's venom has a slow-acting property, so symptoms may appear over several days. Despite its small size, it poses a certain risk for swimmers.
9. Jellyfish Pelagia 12 centimeters
(Nocturnal jellyfish) is one of the most beautiful disc jellyfish, which is common in the waters of the World and Atlantic Oceans, as well as in the Red and Mediterranean Seas. The body diameter of the jellyfish reaches 12 centimeters. The color of the umbrella is purple-red and has ornate frills around the edges. In addition to stinging cells and tentacles, Pelagia has four oral cavities. The jellyfish begins to glow the moment it comes into contact with any objects. The main living creatures that the Nightlight feeds on are benthos, sometimes fry and crustaceans. The jellyfish poses a certain danger to humans, since its injected poison causes burns and, in some cases, shock.
8. Portuguese man of war 25 centimeters
(Physalia) - a jellyfish is a “sailboat”-shaped bubble floating on the surface of the water. The body of the “sailfish” is 25 centimeters, but the tentacles of Physalia can reach 50 meters, which it hides under water. It has a beautiful blue or purple color. The Portuguese man-of-war prefers to feed on fish larvae and small squid. Physalia is one of the most poisonous sea jellyfish. Upon contact with its tentacles, a person receives a severe burn, which is accompanied by acute pain. The injected poison can paralyze everything vitally important organs, so it is difficult for a stung swimmer to stay on the water, and the person drowns. Portuguese man-of-war It is easy to notice from afar, thanks to its bright and beautiful coloring, so meeting it while swimming can be avoided.
(Eared jellyfish) is one of the most common types of large jellyfish. Aurelia's body is almost transparent and reaches 40 centimeters. Numerous thin tentacles have stinging cells that strike prey. Four oral lobes resemble drooping ears, which is why Aurelia received the name Ushastaya. This species feeds mainly on plankton and crustaceans. The eared jellyfish does not pose a danger to humans, and its bite can only cause a burn. IN Asian countries Aurelia is used to prepare exotic dishes.
6. Australian Sea Wasp 45 centimeters
- the most poisonous inhabitant of the World Ocean. The main habitat of the species is the coasts of Indonesia and Australia. The dome of the Sea Wasp is 45 centimeters and is equipped with 60 tentacles, which can reach more than 3 meters when hunting prey. The sea animal has 24 eyes. It instantly stings a passing object in several places at once. Death from poisonous jellyfish stings can occur in just a few minutes. A swimmer who is stung receives enough to cause a heart attack and often drowns. It is quite difficult to notice this jellyfish due to its transparency. Feeds Australian wasp small fish and shrimp.
5. Corner mouth 60 centimeters
– one of largest sea jellyfish, living in Black and Mediterranean seas. The weight of the sea dweller can reach 10 kg, and the diameter of the dome is 60 centimeters. For humans, Cornerot poses no danger and can only cause mild irritation upon contact with the tentacles. Cornerot's umbrella is a "shelter" small fish who are hiding under the dome from danger. This species feeds only on plankton. Jellyfish are actively used in medicine for the preparation of medicines, as well as in cooking. In Japan, Thailand and China, a variety of dishes are prepared from Cornerot.
4. Purple striped jellyfish 70 centimeters
One of the largest and most graceful jellyfish, living in the Gulf of Monterey. The dome of the animal reaches 70 centimeters and has a rich color. Bite Purple jellyfish may cause severe burns to a person. This type has not yet been thoroughly studied by science, so there is very little information about the animal.
(sea nettle) – an inhabitant of the Pacific Ocean opens the top three large jellyfish peace. The body of an adult Chryasora can reach 1 meter, and its numerous tentacles can reach 4 meters. Tentacles severed from the body can exist separately in sea depths for several weeks and sting. Sea nettle stings leave burns in the form of thin scars. Victims experience sharp pain and burning, but do not pose a danger to human health. Chriasora is one of the most beautiful representatives of its own species, which is why the animal is often kept in oceanariums and aquariums. In the ocean, sea nettle feeds on plankton and small jellyfish.
(Lion's Mane) - one of largest species jellyfish that live in the seas Far East. Nomura measures 2 meters in size and can weigh up to 200 kg. Marine animals cause harm to the fishing industry. A giant hairy ball gets caught in the net, entangling it. When the fishermen try to free the net, Nomura sharply stings the man. In case of an allergic reaction to the poison, death from the bite is possible Lion's mane. From time to time, large accumulations of Nomura are observed off the coast of the Sea of Japan.
1. Hairy Cyanea 2.3 meters
Ranks first among giant jellyfish peace. The body of individual individuals of Cyanea can reach 2.3 meters, and the length of the tentacles is 37 meters. The main habitat of this species is seas and oceans. These jellyfish rarely approach the shores and prefer to exist at depths of 20 meters. Giant Cyanea does not pose a serious danger to humans. Its bite can only cause a burn. Eating large individuals plankton and other jellyfish.
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: from 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 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 the corner mouth constructed?
The dome, or umbrella, of a jellyfish is milky white in color, round, spherical in shape, with a purple fringed border running along the edge. 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 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. For for many years 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
One more large jellyfish, living in the Black Sea, is Aurelia. The diameter of its umbrella, or dome, is about forty centimeters, the body is translucent, usually colorless, but sometimes acquires a 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 is thermophilic, but can withstand minus temperature and not die at the same time. Such abilities are observed in many invertebrate animals; some tolerate cooling while moving, others fall into suspended animation.
Mnemiopsis
Jellyfish comparatively small size, up to ten centimeters, which 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 eats eggs small fish, sprat, sprat, 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 to the Black Sea with eastern shores America randomly, in the holds of ships plying 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 similar to 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 " holiday season"When they are most comfortable in their native element, it is warm and there is a lot 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 humans should not disturb harmless creatures, it is better to let them live their lives. The time when jellyfish appear in the Black Sea is not precisely determined, the time is different every year, but approximately it is the end of June - the beginning of July.