Deadly jellyfish
In calm calm weather sea water so pure that it can be seen on great depth... At this time, one can see how in its thickness, like shadows, some strange, almost transparent creatures. By outward appearance they resemble a bell or umbrella. This is jellyfish who got their scary name not by chance.
V ancient greek mythology Medusa (serpentine maiden) was named one of the sisters of the gorgons, winged monsters capable of turning living creatures into stone with a glance. There were snakes on Medusa's head instead of hair.
People gave such a terrible name to the fragile inhabitants of the depths, not only because tentacles fluttering around the edges of their bodies, resembling curving reptiles, but also because with their poison they can inflict defeat on a person, sometimes leading to death.
The poisonous apparatus in all representatives of coelenterates consists of stinging capsules - nematocysts, located mainly on their tentacles in the outer layer. From the outer surface of the stinging capsule, a bristle process - cnidocyle protrudes. In the cavity of the nematocyst filled with poison, there is a thinnest tube coiled into a spiral - a stinging thread.
Touching the cnidocil irritates the nematocyst, the stinging thread unfolds and instantly pierces the victim's skin. At the same time, a toxin is injected through the filament channel. The amount of poison contained in one nematocyst is so small that it can not cause significant harm, but the victim usually touches a large area and receives thousands of tiny "injections". All this leads to local "burns" or general poisoning.
The composition of the poison depends on the species and family of coelenterates. It may include highly toxic compounds (thalassin, congestin, hypnotoxin), as well as substances that are physiologically active for humans (serotonin, histamine).
The most frequent and severe poisoning in humans is caused by poisonous intestinal cavities: physalia and jellyfish chironex (sea wasp), chiropsalmus, gonionema and pelagia.
Guinness book record holder
But first, let's dwell on cyane. According to the well-known Guinness Records, this is the largest coelenterate animal on the planet.
In 1870 gigantic arctic jellyfish (Suanea capillata arctica) - arctic cyanea- was carried by waves ashore in Massachusetts Bay (USA) from North Atlantic... Its bell was 2.28 m in diameter, and its tentacles were 36.5 m long!
She dwells in northern parts Atlantic and Pacific oceans: from south coast New England before Arctic Ocean; from the coast of France to the north of Russia; in the Baltic Sea; from Alaska to Pyogend Sound, Japan and China.
One of the eyewitnesses happened to meet such an unusual creature in the Sea of Japan in 1970.
When I first saw her under water in front of the glass of the underwater mask, I just could not believe my eyes. Red jellyfish! She swam unusually fast, which made her very different from her slow and passive Black Sea counterparts, smoothly and gracefully "working" with her whole body. Approaching this amazing creature, I examined it in detail.
Yes, from a distance I, perhaps, slightly confused with the color. The jellyfish was dark crimson rather than red. Its parachute is yellowish in the center, and the edges are framed with a figured cut light border. From the animal's mouth in the form of wide crimson-red curtains descended oral cavity... The ruby tentacles stretched fifteen meters deep. Such a beauty not only can burn with her tentacles, I thought, she is capable of swallowing a person whole.
But the desire to certainly show such a miracle to his comrades who remained on the shore helped to overcome the fear. And what, in fact, be afraid - I am in a neoprene diving suit and gloves, it is simply impossible to get burns. Pushing the jelly-like inhabitant with his hands in front of him, he began to transport the "beauty" to the shore.
True, it was not possible to avoid troubles. Several times, despite all the precautions, the tentacles of the qianxi touched my chin. The impression was as if nettles had been lashed at him. Finally, my captive is at the shore, and my friends, having gone knee-deep into the water, are looking with curiosity at this unusual sea monster.
“What a wonderful specimen,” said Nikolai, a biologist by profession. - I have encountered cyanea more than once during underwater research, but I have never seen such a large one.
- It's OK. The poison of this jellyfish is weak, and all the troubles will soon pass.
My comrades, wearing wetsuits and rubber gloves, towed unusual creature to the depth. And then everyone admired this poisonous miracle floating away into the open sea for a long time.
Nikolay was right: the burning sensation and redness on the skin of the face completely disappeared without treatment after a few hours.
In Western Europe, cyanea has become a bad name. Many experts consider it extremely poisonous. In particular, American specialist in the field of marine biotoxins, Bruce Halstead included this animal in his book Dangerous Marine Animals. Perhaps specimens from the Atlantic do indeed have a potent poison, but those that live in our seas - White, Baltic, in the seas Of the Far East are not that scary at all.
According to the authoritative Russian scientist D. Naumov, the author of the well-known work "Scyphoid jellyfish of the seas of the USSR", the pathogenic effect of cyane toxin is negligible. It can cause only slight reddening of the skin and short-term mild itching.
The question arises, is it plausible then the story of Arthur Conan Doyle "The Lion's Mane", which he wrote under the impression of a conversation with his friend, the famous English zoologist R. Lancaster? (In the story, as you know, cyanea kills the teacher Markferson with its poison.) Most likely not. There have not yet been any reliable deaths from contact with cyanide. So the conclusion that the poison of this jellyfish is "especially strong and can be fatal to humans" has not yet been confirmed.
On the horizon "Portuguese boat"
One day famous traveler Yuri Senkevich spoke about the meeting with dangerous jellyfish — « portuguese boat"When, while sailing across the Atlantic on the papyrus ship Ra, one of Heyerdahl's sailors fell into the tentacles of this huge, many-meter creature. So the word famous TV presenter Yu Senkevich.
"During the expedition with Heyerdahl on the boat" Ra "with the American Norman Baker, there was quite a funny story... There is such a sea animal, physalia, something like a brush rises above the water, and threads up to 20 m long go down. This "baby" secretes nerve poison. This very physalia, along with the wave, hit Norman's chest. All my attempts to clean off the "jellyfish" that hugged my friend were unsuccessful. And then Heyerdahl remembered that ammonia was used in such cases. I instantly realized that we could give Norman the ammonia preparation immediately and all at once. They took a coconut shell, let it go in a circle and carried out an effective urine therapy, pouring it over with this international medicine. Physalia lagged behind Norman. "
Physalia (Physalia physalis) got its name from Dr. Marie Physalix, who discovered and described it. Inhabits it strange creature on the border of water and air.
Above the sea surface, a towering brightly colored air bubble is clearly visible, casting blue, purple, in places with bright red colors. Driven by a favorable wind, this colorful ball travels long distances like a sailing ship.
It is interesting to note that the physalia bubble is also a complex hydrostatic apparatus, which, depending on the conditions, changes its specific gravity.
As soon as the excitement intensifies, the excess gas is immediately removed from the bubble, and the physalia goes on to dive.
As soon as the sea calms down, special glandular cells fill the empty containers with gas, and the animal floats to the surface, sparkling with its amazingly bright colors.
This color was the reason why the physalia was called the "Portuguese battleship" ("Portuguese man-of-war"). It is known that in the Middle Ages the Portuguese painted their caravels in all the colors of the rainbow.
The shape of the bladder in physals living in the North and Southern hemispheres, is different, and they never enter "foreign territory". This feature helps the siphonophore to resist the Earth's rotation force, the Coriolis force, and provides the "northern" individuals with movement to the left, and the "southern" ones - to the right. This is another prime example of natural selection.
In the water, under the bladder, there are bottle-shaped polyps with the mouth openings facing downward. Each such polyp is equipped with a long tentacle - an ar-canchik, seated along its entire length with special stinging cells that hit the victim. The air bubble reaches a length of 30 cm, and the lasso stretches down to 30 m.
Physalia poison in its nerve-paralytic effect resembles the venom of a cobra. Touching the body of a person, the tentacles of the siphonophore burn strongly, the victim feels acute pain, may lose consciousness and drown.
Physalia lives in the tropical Atlantic, to the north it reaches the Bay of Fundy, the Hebrides and the Mediterranean Sea. A closely related species occurs in Hawaiian Islands and in southern Japan.
Invisible killer
For the fourth year, the flames of World War II blazed over the Pacific Ocean. Ships destroyed by torpedoes were sinking. Planes fell into the sea, leaving a smoky plume. People struck by bullets disappeared without a trace in the waves.
And suddenly, both belligerent powers - the United States and Japan - suddenly had a common enemy. He horrified soldiers, sailors and officers.
People fleeing from sinking ships and wrecked planes ended up in the water. From time to time, one of the floating suddenly screamed wildly and immediately hid under the waves. The surviving eyewitnesses swore that often there were no sharks in the area of the tragedy, the victims of which were the unfortunate in other cases. Long time the cause of death of people remained an absolute mystery. There were no wounds on the removed bodies, only in some places red stripes were observed, as if from a blow with a whip.
Finally, after a long search, the Australian zoologist Southcott found a mysterious killer. It turned out to be the box jellyfish chironex, or "sea wasp" (Chironex fleckeri). In 1944, 100 deaths were officially recorded off the coast of the Green Continent alone, the culprit of which was this jellyfish.
By the way, even today Australians fear her more than sharks. The fear is fully justified. Exactly this poisonous creature living in the oceans. The poison of one jellyfish is enough to kill 60 people! Doctors believe that the pain from the "burn" of this animal surpasses any other that only falls to the lot of a person.
Outwardly, the "sea wasp" looks quite harmless. This creature has a transparent bell-shaped body about the size of a football (sometimes smaller), similar to a rounded cube. From the bottom corners of the cube there are four thick "arms" which are divided into several "fingers". They end in slender bluish or reddish tentacles 4.5 m long. There are usually about 60 tentacles. The main danger lies in them.
"Sea Wasp" is capable of speeds up to two knots! (One knot is a mile per hour). She can emerge from the depths, catch up with a swimming person, "burn" him and hide. That is why the unexpected death of people in the water remained unsolved for a long time.
The chemical composition of the poison of Chironex is not fully understood. It is very persistent and persists for a long time even in dead jellyfish.
The most common "sea wasp" in Australian waters, but often found off the coast West Africa, near the Bahamas, along Atlantic coast North America and the Philippines (almost entirely favorite places rest of tourists, and ours too). The jellyfish usually stays in the darkened places of the coastal strip, so its transparent body is difficult to see even for a person with good eyesight.
A person who accidentally touches the "wasp" literally immediately feels a burning pain, which within two or three minutes becomes so strong that he loses consciousness and drowns. No other animal on the globe produces a poison that can kill for such a short time... Death from the "burn" of this killer can occur within 30 seconds.
If it was possible to immediately pull out of the water a person who had bumped into a jellyfish, then he usually had a weakening pulse and shortness of breath. And the end was always the same. Autopsy revealed that the airways were clogged with foamy mucus, and some of the victims had cerebral hemorrhage. Experts believe that the cause of death is painful shock and respiratory distress.
In 1971, Australian scientists received an antidote for " sea wasp»From the blood of a sheep, which was injected with a non-lethal dose of poison. Today, in the coastal regions of the Northern Territory and North Queensland, doctors are supplied with this antidote. If you introduce it to the victim immediately after the "burn", then it is very effective: almost immediately it normalizes breathing and quickly relieves pain.
A close relative of the "sea wasp", the jellyfish chiropsalmus (Chiropsalmus quadrigatus), is also very dangerous. She lives in the Atlantic - from Brazil to North Carolina, in Indian Ocean and at north coast Australia. Death of the strongest and healthy person from a "burn" by this jellyfish can come in 3-8 minutes. Its poison quickly affects the central nervous system and leads to paralysis of the heart.
"Kiss" of the gonionema
“Where is Australia and where are we? Now, if only these "wasps" were found here! " - the reader might think. But, firstly, more and more Russians travel around the world, and secondly, we also have something similar. This is a small jellyfish gonionema, she is "cross". This is the most dangerous animal of our seas. She lives in the waters of Primorye, in temperate latitudes the northern part of the Pacific Ocean, in the Sea of Japan, the Amur Bay, in the Tatar Strait off the coast of South Sakhalin, in the region of the Kuril Islands and Japan.
The body of the jellyfish is a flattened bell with a diameter of only a patch. It clearly shows four cross-shaped glands of brown-red color. By this "cross", gonionema can be easily distinguished from other species. The edges of the mini-bell are framed by up to 80 tentacles with suction cups. Touching them to the skin is perceived as a nettle burn. But God forbid you get burned like that!
The skin turns red, covered with small white blisters. After 15-20 minutes, the torment begins - a feeling of suffocation, pain in the lower back and joints. The disease is difficult, the acute period usually lasts 4-6 days. However, even after recovery, people can suffer from pain for a month.
The poison of the "cross" often causes anaphylaxis - increased sensitivity to re-introduction of even very small doses of the same toxin. This means that already the second meeting with the gonionema may end in death!
About 30 years ago, one of the victims had to experience all the "beauty of kissing" a gonionema - it was on the Japanese mors in the Peter the Great Bay.
I swam with a mask, fins and a snorkel near the shore. A thicket of seaweed and sea grass appeared below. Above them hovered two tiny jellyfish with a diameter of a ten-kopeck coin. Catching up with each other, transparent creatures rapidly moved in the water column. One of them, having done an incredible somersault, sucked to my chest. Throwing it away, I felt a slight burning sensation, but did not attach any importance to it. On the shore, when I was taking off my equipment, there was a slight dizziness, terrible pain in the lower back and limbs. I had to undergo medical treatment. Only two weeks later I was discharged from the hospital.
Poisoning with gonionema poison is also massive. In 1970, for example, during one day, while swimming in the Amur Bay, 1360 bathers suffered from contact with gonionem, of which 116 were hospitalized in a serious condition.
It is not so easy to get rid of gonionema in water. As if afraid to miss the victim, she firmly clings to the body.
In recent years, Pelagia noctiluca (Pelagia noctiluca) has become a big problem for people. This is a jellyfish with an umbrella diameter of about 5-6 cm, with 8 whip-like red tentacles up to 50 cm long. It is painted in a delicate purple-red color and glows in the dark, for which it received the second name "night light". Found in the Great Barrier Reef off the coast of Australia.
In 1976, pelagia appeared in the Mediterranean. Contact with her caused burning pain in the swimmers, sometimes accompanied by shock. The defeat was often massive. In 1978 alone, over 250 thousand cases of her burns on the beaches of the Adriatic were noted.
Forewarned is armed
If you suddenly decide to swim in places where poisonous jellyfish live, remember that protective clothing, for example, a wetsuit covering the entire body, is best saved from their toxins. When there is none, ordinary tights will help.
Do not wonder. In the West, participants in surfing competitions (boarding on a wave) pull as many as two pairs! One covers the legs, and the second is worn over the head on the hands. Such a suit "a la Fantômas" protects against the stinging cells of jellyfish: their stings are too short to reach the skin.
Without protective clothing, contact with the "sea jelly" is difficult to avoid, because transparent creatures in the water are not easy to see. Swimming in the sea after a storm, you can get "burns" not even from jellyfish, but from floating fragments of their tentacles.
But if, nevertheless, misfortune has occurred, they will come to the rescue modern achievements medicine. As it became known recently, Israeli scientists have invented a universal remedy against jellyfish "burns", from which about 130 million people worldwide suffer every year.
Jellyfish appeared a long time ago. Due to their shapeless appearance, these animals were called jellyfish. By name, they drew an analogy with Medusa the Gorgon - the Greek mythical goddess. They were tied by tentacles, which were on the Gorgon's head in the form of snake hair, which, like jellyfish, were poisonous.
Where do they live?
Jellyfish are found all over the world and are found in salty seas. Jellyfish differ by place of residence. Each body of water in the World Ocean contains a separate species that does not spread beyond its boundaries. There is only one type of jellyfish in the whole world, which can be found in every freshwater body of water.
Also, in the same sea or ocean, there can be such different jellyfish as:
- cold water (warm water);
- deep water (shallow water, or those that stick to the surface).
However, even those that are at the top of the reservoir at night sink to the bottom during the day, this is due to the search for food. Everything is clear with vertical movement, but let's talk about horizontal movements in more detail. While swimming, they actively push water out from under their umbrella, thanks to the contraction of muscle fibers that are located along the edge of the jellyfish's dome.
But still, the speed of movement is small and it accelerates only because of the current. In a relaxed state, it sinks to the bottom. Jellyfish are so primitive animals that they do not even interact with each other, that is, they are solitary in life.
Nutrition
Jellyfish are predators. They grab the victim and eat it. They feed on small marine life - fish roe, small fish, and fish, smaller jellyfish, zooplankton. The size of the food depends on the size of the jellyfish itself, i.e. something that she can swallow whole.
Jellyfish appearance
All jellyfish have a primitive structure, so they are similar internally and have a uniform physiology. Jellyfish can be distinguished by their radial symmetry of organs. Also, a distinctive feature can be called the fact that the number of organs is always a multiple of four (8 blades on an umbrella).
Jellyfish spends all the time in water, and it itself is 95% water. The jellyfish has no bones and therefore, as soon as it hits the land, it immediately loses its ability to move and dries up instantly. The consistency of jellyfish is similar to jelly, which is why it is attractive.
The body size of a jellyfish in diameter is from 2mm to 2.2 meters. She has no eyes, but there are special organs located along the edge of the umbrella. They determine the location (bottom or top), react to lighting. With their help, jellyfish know when it is day and when it is night.
In the water, jellyfish are almost invisible, they are transparent. This is great disguise and protection. There are stinging cells on the tentacles and other parts of the body that secrete poison. This poison can cause death or severe burns. Almost all jellyfish living in cold seas white... Jellyfish tropical warm waters brightly colored.
Jellyfish tissue structure
The fabric consists of two layers, bonded together with adhesives. It is the tissues that are responsible for the functions that the jellyfish's body can perform. Which functions we will consider in the form of a list:
- The outer part of the jellyfish. The cells located here are responsible for " locomotor apparatus", Genus extension. This part looks smooth and is convex;
- The inside of the jellyfish. The cells that are located in this layer are intended only for digestion. This part looks like a bag.
- The mouth is located at the bottom of the dome. It is he who is hallmark each type of jellyfish, since, being in the middle, it is very different in structure;
- Special attention should be paid to the consideration of the umbrella, or rather its surroundings. Here are the tentacles, which are also varied in appearance. They can be thick and long or short and thin, long and thin, almost threadlike, etc.
Scientists do not give an unambiguous answer to the question of how long jellyfish live. Many agree that life cycle these animals are short-lived and the life span of most species is from two to six months.
Recently, zoologists have discovered that among the representatives of this species there are specimens that never die and are always reborn. Therefore, the jellyfish Turitopsis Nutrikula is considered to be the only immortal creature on the planet.
Who are jellyfish
Zoologists, speaking of jellyfish, usually mean all mobile forms of coelenterates creeping animals (a group of multicellular invertebrates of the animal world), which catch and kill their victims with the help of tentacles.
These amazing animals live only in salt water, and therefore they can be found in all oceans and seas of our planet (except inland), sometimes in closed lagoons or lakes with salt water on coral islands. Among the representatives of this class there are both thermophilic animals and those preferring cold waters, species that live only near the surface of the water, and those that live only at the bottom of the ocean.
Jellyfish are solitary animals, since they do not communicate with each other in any way, even if the currents knock them together, thus forming a colony.
These creatures got their modern name in the middle of the 18th century thanks to Karl Lineus, who hinted at the mythical head of Medusa the Gorgon, the resemblance to which he noticed in these representatives of the animal world. This name is not without reason, since these animals are similar to her.
This amazing animal is 98% water, and therefore has a transparent body with a slight tint, which in appearance resembles a jelly-like bell, umbrella or disc, moving by contraction of the bell wall muscles.
Tentacles are located along the edges of the body, the appearance of which directly depends on which species it belongs to: in some they are short and thick, in others they are long and thin. Their number can range from four to several hundred (but at the same time it is always a multiple of four, since the representatives of this class of animals are characterized by radial symmetry).
These tentacles are composed of string cells, which contain poison, and therefore are directly intended for hunting. Interestingly, even after death, jellyfish are able to sting for another half a month. Some species can be deadly, even to humans. For example, the animal known as the "Sea Wasp" is considered the most dangerous poisonous animal in the world's oceans: scientists say that its poison is enough to poison sixty people in a few minutes.
The outer part of the body is smooth and convex, while the lower part resembles a bag. In the center of the lower part there is a mouth: in some jellyfish it looks like a tube, in others it is short and wide, in others it resembles short clubs. This hole also serves to remove food debris.
These animals grow throughout their life, and their size largely depends on the species: among them there are very small ones, no more than a few millimeters, and there are also huge ones, the body size of which exceeds two meters, and together with the tentacles - all thirty ( for example, the largest jellyfish in the world ocean, Cyanea, which lives in the Northwest Atlantic, has a body size of more than 2 m, and with tentacles - almost forty).
Despite the fact that these marine animals lack brains and sensory organs, they have light-sensitive cells that act as eyes, thanks to which these organisms are able to distinguish between darkness and light (they, however, cannot see objects). Interestingly, some specimens glow in the dark, while in species living on great depth, the light is red, while those that live closer to the surface are blue.
Since these animals are primitive organisms, they consist of only two layers, which are connected thanks to a special adhesive substance - mesoglia:
- external (ectoderm) - a kind of analogue of skin and muscles. Here, too, are the rudiments of the nervous system and germ cells;
- internal (endoderm) - performs only one function: it digests food.
Modes of movement
Since all representatives of this class (even the largest individuals, whose weight exceeds several centners) are almost unable to resist sea currents, scientists consider jellyfish as representatives of plankton.
Most species water streams still do not give in completely and, albeit slowly, they move, using the current and thin muscle fibers their body: contracting, they fold the body of the jellyfish like an umbrella - and the water that is in the lower part of the animal is sharply pushed out.
As a result, a strong stream is formed that pushes the animal forward. Therefore these sea creatures always move in the direction opposite to the mouth. Where exactly they need to move, they are helped to determine the organs of balance located on the tentacles.
Regeneration
One more interesting feature of these creatures is their ability to restore the lost parts of the body - absolutely all the cells of these animals are interchangeable: even if this animal is divided into parts, it will restore them, thus forming two new individuals! If this is done with an adult jellyfish, an adult copy will appear, from a jellyfish larva - a larva.
Reproduction
Looking at these amazing translucent creatures, many ask themselves the question of how jellyfish reproduce. Reproduction of jellyfish is an interesting and unusual process.
Answering the question of how jellyfish reproduce, it is worth noting that in this case, it is possible both sexual (they are of different sexes) and vegetative reproduction. The first involves several stages:
- In these animals, the sex cells mature in the sex glands;
- After the eggs and spermatozoa mature, they go out through the mouth opening and fertilize, resulting in a jellyfish larva - planula;
- After some time, the planula settles to the bottom and is fixed on something, after which a polyp appears on the basis of the planula, which multiplies by the budding method: on it, layering on top of each other, daughter organisms are formed;
- After some time, they exfoliate and float away, representing a newly born jellyfish.
The reproduction of some species is somewhat different from this scheme. For example, the pelagic jellyfish does not have a polyp stage at all - cubs appear directly from the larva. But bougainvillea jellyfish, one might say, are born, since polyps are formed directly in the gonads, without separating from adults, without any intermediate stages.
Nutrition
These amazing animals are the most numerous predators on our planet. They feed mainly on plankton: fry, small crustaceans, fish caviar. Larger specimens often catch small fish and smaller relatives.
So, jellyfish see almost nothing and do not have any sense organs, they hunt with string tentacles, which, having caught the touch of edible food, instantly inject poison into it, which paralyzes the victim, after which the jellyfish eats it. There are two more options for catching food (here a lot depends on the type of jellyfish): the first - the prey sticks to the tentacles, the second - gets entangled in them.
Classification
Exists the following types jellyfish, differing from each other in structure.
Hydromedusa
Hydroid jellyfish are transparent, small in size (from 1 mm to 3 cm), four tentacles and a long, tube-shaped mouth are attached to the body. Among prominent representatives hydromedusa - jellyfish Turritopsis nutricula: The only creature discovered by humans that scientists have declared is immortal.
Having reached maturity, it sinks to the bottom of the sea, transforming into a polyp, on which new formations are formed, from which new jellyfish subsequently arise.
This process is repeated more than once, which means that it is constantly being reborn, and can die only if some predator eats it. Like these ones Interesting Facts scientists recently told the world about jellyfish.
Scyphomedusa
Scyphoid jellyfish have a more complex structure in comparison with hydro-jellyfish: they are larger than representatives of other species - the largest jellyfish in the world, the Cyaneus jellyfish, belongs to this class. This giant jellyfish about 37 meters long, it is one of the longest animals on Earth. Therefore, she eats a lot: during her life, the largest jellyfish eats about 15 thousand fish.
Scyphomedusa have a more developed nervous and muscular system, the mouth is surrounded by huge amount stinging and tactile cells, and the stomach is divided into chambers.
Like all jellyfish, these animals are predators, but deep-sea ones also feed on dead organisms. The touch of a scyphoid jellyfish to a person is quite painful (the feeling if a wasp had bitten), and a trace resembling a burn often remains at the point of contact. Her bite can also cause an allergic reaction or even painful shock. Having seen this animal, it is advisable not to take risks and, while swimming by, do not touch it.
One of the brightest specimens of this species, in addition to the Cyanea jellyfish, is also the Aurelia jellyfish (the most typical representative) and the Golden jellyfish, an animal that can only be seen in the archipelago. Rocky islands in Palau.
The golden jellyfish is notable for the fact that, unlike its relatives living only in the seas, it lives in Lake Jellyfish, which connects to the ocean. underground tunnels and filled with slightly salted water. Representatives of this species differ from marine individuals also in that they have no age spots, no stinging tentacles, and no tentacles that surround the mouth.
Although the golden jellyfish belongs to scyphomedusa, over the years it has turned into a completely different species that does not pose a danger to humans, since it has significantly lost its stinging ability. An interesting fact is that the Golden Jellyfish began to grow on its body green algae from which it receives part of the food. The Golden Jellyfish, like its marine relatives, feeds on plankton and has not lost the ability to migrate - in the morning it swims to the east coast, in the evening it swims to the west.
Box jellyfish
Box jellyfish have a more perfect nervous system in comparison with other representatives of the class of creepers. They are the fastest of all jellyfish (capable of speeds up to 6 m / min.) And can easily change the direction of their movement. They are also the most dangerous representatives jellyfish for humans: the bites of some representatives of box jellyfish are fatal.
The most poisonous jellyfish in the world belongs to this very species, lives near the Australian coast and is called Box Jellyfish or Sea Wasp: its poison can kill a person in just a few minutes. This wasp is almost transparent, of a pale blue hue, which is why it is difficult to notice on the water, which means that it is easier to stumble upon it.
The Sea Wasp is the largest jellyfish in its class - its body is the size of a basketball. When the sea wasp simply swims, its tentacles contract to 15 cm in length and are almost invisible. But when the animal hunts, they stretch out to three meters... Sea Wasps feed mainly on shrimps and small fish, and they themselves are caught and eaten sea turtles Are the only animals on our planet that are insensitive to the poison of some of the most dangerous creatures on the ground.
The marine jellyfish, which is called the wasp, belongs to the category of box jellyfish, a type of flying jellyfish. 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 released from its tentacles depresses the nervous system, causes severe burns and unbearable pain. As a result, it develops heart attack, which can lead to cardiac arrest. Timely provided health care in some cases, it can save a person's life. However, there are cases lethal outcome within a very short period of time after meeting a poisonous monster. Even a dead sea wasp (photo below) is a source increased danger... The poison-toxin disintegrates only a week after the death of the jellyfish, therefore it is absolutely impossible to touch it.
Unfortunately, this type of jellyfish is found in places beach resorts and diving sites. The danger of meeting a sea wasp lies in the fact that it is almost invisible. Therefore, precautions should not be neglected.
Habitat
Jellyfish is found in Pacific Indo-western part of it and in South-East Asia... Most often, the sea wasp is found near the coast of northern Australia, where there are many corals and a shallow sea in summer months from November to March. Jellyfish inhabit coastal zones at a respectful distance from the coast, but when the sea is rough, they can be thrown ashore.
Appearance
The sea wasp is the most major representative its class. The body of the jellyfish is a transparent dome, which is 95% water. Its shape is similar to a rounded cube, hence the name box jellyfish. The size of the dome is 20-45 cm, and can be compared in size to 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 the image, and one only reacts to light. Scientists cannot explain the presence of such a number of eyes in a jellyfish, because the information received from what they see 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 each. The probes are 15 cm long and 5 mm thick, when hunting for prey, they extend up to three meters. Each tentacle is covered in stinging cells containing a 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 benthic organisms, but the most favorite delicacy is shrimp. Going out to fish, they stretch out their tentacles and freeze in place. The jellyfish traps the victim in the probes, pierces the skin, injects poison, kills and swallows. By the type of bite, it resembles a wasp, only the poison is much more toxic, incomparable even with 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 throughout this period they continue to grow.
Sea wasps reproduce offspring in the same way as other individuals belonging to this species. They multiply in summer period going in large flocks and swimming closer to the shores. During this period of time, Australia is trying to close all the beaches.
The male spews a dose of sperm into the water while near the swimming female. The latter swallows it, fertilization occurs. Inside the female, larvae develop, which after a while are thrown into the water and settle on the surface of the seabed. They stick to stones, shells, snags, forming polyps.
As a result of budding, small jellyfish grow from the polyps, which break off and begin an independent life. They immediately orient themselves in the sea space and feed on plankton on their own.
Who do the Australians call the sea wasp?
A small marine animal, due to its transparency, is almost invisible in the water. It is an active predator and represents great danger for animals and humans. This animal swims well and maneuvers perfectly among algae and corals, moving at a speed 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 into the upper layers of the water. The speed of the attack of the jellyfish on the victim is very high.
And the poison contained in the tentacles is so poisonous that when stung, any creature instantly dies. Moreover, she stings several times in a row, bringing the concentration of the poison to a lethal value. Australian sea wasp - this is the name of this jellyfish - it is dangerous for all living organisms, with the exception of the poison of these predators does not work on them, and turtles eat box jellyfish with appetite.
The consequences of meeting a sea wasp
Cubomedusas, although extremely dangerous to human life, do not attack him themselves, on the contrary, they tend to swim to the side. She can sting a person purely by accident. Often the victims are scuba divers who are not protected by special suits.
When the skin touches the tentacle, there is a terrible pain, severe redness and swelling. Most often, a person's heart stops and he drowns. Some managed to get ashore, but paralysis came. respiratory system and the man was dying. After autopsy, it was found that the victims' respiratory organs were filled with mucus, while others were dying of cerebral hemorrhage. There were cases that a person did not die immediately, but no one survived.
Protection of the life of vacationers
During the migration season of jellyfish, mesh fences are installed on the beaches to prevent them from entering the swimming area. Despite this, small specimens penetrate the mesh cells, so the beach administration warns vacationers about the danger and categorically 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 introduce an antidote - antitoxic serum and urgently hospitalize the victim. But this does not give any guarantee for the preservation of life.
- It is known that jellyfish appeared more than 600 million years ago, much earlier than dinosaurs, crocodiles and sharks.
- Jellyfish and polyps are different stages in the life span of the same creature.
- The sea wasp is called a jellyfish, which breathes with its entire dome and stings like a wasp.
- The absence of a brain does not prevent them from perceiving nervous stimuli from the organs of touch and vision.
- They have two nervous systems.
Jellyfish are able to move underwater, sucking in and pushing out water as a result of the contraction of the umbrella muscles, but they mostly drift due to the current. Scientists believe they belong to plankton.
Since ancient times, people have known strange shapeless sea animals, which they gave the name "jellyfish" by analogy with the mythological ancient Greek goddess Medusa the Gorgon. The hair of this goddess was a wiggling bundle of serpents. The ancient Greeks found similarities between the evil goddess and sea jellyfish with poisonous tentacles.
The habitat of jellyfish is all the salty seas of the World Ocean. Only one known freshwater species of these marine life... Each species occupies an area limited to one body of water and will never be found in another sea or ocean. Jellyfish are cold-water and thermophilic; deep-sea and those that stay near the surface.
However, such species swim near the surface only at night, and during the day they dive to the depths in search of food. The horizontal movement of jellyfish is passive - they are simply carried by the current, sometimes over long distances. Due to their primitiveness, jellyfish do not contact each other in any way, they are solitary animals. Large clusters jellyfish are explained by the fact that the current brings them to places rich in food.
Due to the highly developed colorless mesoglea, the body of the jellyfish " flower hat"(Olindias formosa) looks almost transparent Varieties of jellyfish
More than 200 species of jellyfish are known in nature. Despite the primitive structure, they are very diverse. Their sizes range from 1 to 200 cm in diameter. The largest jellyfish - lion's mane(cyanea). Some of its specimens can weigh up to 1 ton and with a tentacle length of 35 m.
Jellyfish are shaped like a disc, umbrella or dome. Most jellyfish have a transparent body, sometimes bluish, milky, yellowish. But not all species are so inconspicuous, there are truly beautiful among them, bright colors: red, pink, yellow, purple, speckled and striped. There are no green jellyfish in nature.
Species such as equorrhea, nightlight pelagia, ratkea in the dark can glow, causing a phenomenon called bioluminescence. Deep-sea jellyfish emit red light, while floating near the surface - blue. There is special kind jellyfish (stavromedusa) that hardly move. They are attached to the ground with a long leg.
Jellyfish structure
The internal structure and physiology of jellyfish are uniform and primitive. They have one main distinctive feature- radial symmetry of organs, the number of which is always a multiple of 4. For example, a jellyfish umbrella can have 8 blades. The body of a jellyfish has no skeleton; it is 98% water. Thrown ashore, the jellyfish is unable to move and dries up instantly. In consistency, it resembles jelly, which is why the British called it “jelly fish”.
Body tissues have only two layers, which are interconnected by a sticky substance and perform different functions. The cells of the outer layer (ectoderm) are “responsible” for movement, reproduction, and are analogs of the skin and nerve endings. The cells of the inner layer (endoderm) only digest food.
The outer part of the body in jellyfish is smooth, mostly convex, the inner (lower) shape resembles a bag. The mouth is located at the bottom of the dome. It is located in the middle and is very different in structure from different types jellyfish. The umbrella is surrounded by trapping tentacles, which, depending on the species, can be either thick and short, or thin, threadlike, long.
What jellyfish eat
Jellyfish are predators, they consume only animal food (crustaceans, fry, small fish, eggs). They are blind and have no sense organs. Jellyfish hunt in a passive way, catching with their tentacles what is edible that it brings with the current. The trapping tentacles kill the victim. This is done different ways.
This is the largest jellyfish in the world - cyanea, or lion's mane ( Cyanea capillata), it is her long tentacles that can reach 35 m in length! Some types of jellyfish inject poison into the victim, others stick prey to the tentacles, and still others have sticky threads in which it gets entangled. The tentacles push the paralyzed victim to the mouth, through which undigested debris is then expelled. Interestingly, jellyfish living at depths attract prey with their bright glow.
How jellyfish reproduce
Jellyfish have vegetative (asexual) and sexual reproduction... Outwardly, males are no different from females. Sperm and eggs are excreted through the mouth into the water, where fertilization takes place. After this, a larva (planula) develops. The larvae are not able to feed, they settle to the bottom and a polyp is formed from them. This polyp can multiply by budding. Gradually, the upper parts of the polyp separate and float away; they are actually young jellyfish that will grow and develop.
Some jellyfish species lack the polyp stage. Juveniles are immediately formed from the planula. There are also species in which polyps are already formed in the gonads, from which small jellyfish are born. From each egg in jellyfish, several individuals are formed.
Vitality of jellyfish
Although jellyfish do not live long - from several months to 2-3 years, their numbers recover very quickly even after various cataclysms. Their reproduction rate is very high. Jellyfish quickly restore lost body parts. Even if you cut them in half, two new individuals are formed from the halves.
It is interesting that if such an operation is carried out in different ages jellyfish, then an individual of the corresponding stage of development grows from the tissues. If you divide the larva, then two larvae will grow, and from the adult parts - jellyfish of the corresponding age.
Jellyfish swimming "upside down" Jellyfish and people
Some types of jellyfish are dangerous to humans. They can be roughly divided into two groups. Some cause allergies, while the poison of others affects the nervous system and can cause serious muscle and heart problems, and in some cases, death.
In order not to put yourself in danger, you need to avoid touching jellyfish, both living and dead. In case of burns, rinse the injured area with water, or better with a vinegar solution. If the pain persists and there are complications, you should immediately call a doctor.
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