Jellyfish aurelia is a common jellyfish that everyone who has been to the sea has seen. Aurelia jellyfish or eared jellyfish live in the Black, Baltic, Barents, Japanese, Bering and White seas. In addition, aurelia is found in tropical seas and Arctic zones.
These jellyfish swim poorly; they can only rise from the depths and sink, hovering motionless while contracting their umbrellas. After a storm, these jellyfish are found in huge numbers on the shore.
Aurelia's umbrella has flat shape, in diameter it is 40 centimeters. The umbrella is completely transparent because it is formed from a non-cellular substance, which is almost 98% water. In this regard, the weight of a jellyfish is close to the weight of water, which makes the swimming process easier. Small but very mobile tentacles run along the edge of the umbrella. Located on the tentacles big number stinging cells.
In the middle of the bell there is a quadrangular mouth, 4 scalloped oral lobes hang from it, which also actively move. Jellyfish use stinging cells to kill prey. Jellyfish mainly feed on small crustaceans. The oral lobes contract and pull prey toward the mouth.
Aurelias are dioecious jellyfish. Reproduction of aurelia
Aurelias are dioecious creatures. The body of males contains milky-white testes, clearly visible and shaped like half rings. Females have purple and red ovaries, which are visible through the bell. The gender of a jellyfish can be easily determined by the color of these glands.
Reproduction in Aurelia jellyfish occurs only once, after which they die. These jellyfish, unlike most of their relatives, take care of their offspring. When a jellyfish hangs in the water, its mouth lobes are lowered down, so the eggs that come out of the mouth opening fall into the gutters, move along them and penetrate into the pockets, where they are fertilized and develop. After fertilization, the egg begins to divide, first in two, then each half divides in two again, and so on. Thus, a multicellular single-layer ball is obtained. A certain number of cells are immersed inside, just like a rubber ball is squashed, this is how a two-layer embryo is obtained.
The cells of the embryo are covered on top with a large number of cilia, with the help of which the embryo swims. From this time on, the embryo transforms into a larva called a planula. The larva swims in the water for some time, and then sinks to the bottom and attaches itself to it with the help of its anterior end. Then a mouth with a crown of tentacles breaks out on the back, upper part of the body. Thus, the planula is transformed into a polyp, which is similar in appearance to hydra.
After some time, the polyp divides using transverse constrictions. The constrictions cut into the body of the polyp, and it takes on a resemblance to a stack of plates. These discs are young jellyfish that are beginning an independent life. That is, in this way, asexual reproduction of polyps occurs; they cannot reproduce sexually. Only jellyfish can reproduce in this way.
Jellyfish food
In Japan and China, Aurelia jellyfish are used as food; in these countries, fishing for these creatures is organized. Large aurelias are used for pickling. The mouth blades of the caught jellyfish are separated, and the umbrella is thoroughly washed until the digestive canals are cleaned. Only the non-cellular substance of the umbrella can be processed. The Chinese call jellyfish meat “crystal”. Jellyfish are eaten boiled and fried with a variety of seasonings, and salted jellyfish are used in solariums.
For humans, the stinging cells of aurelia jellyfish are safe, unlike the cornet jellyfish that live in the Black and Azov Seas. Cornerotes do not have tentacles; they grab prey with their branched mouth cavities, the edges of which are similar to root outgrowths. These outgrowths are strewn with stinging cells that contain the toxic substance rhizostomin. This substance causes severe burns to humans. Cornerotes differ from eared jellyfish by the presence of a border along the edge of the umbrella of a bright purple or blue color. Large specimens of cornetroots reach a diameter of 50 centimeters.
Cyanea
The Barents and White Seas are home to a cold-water giant, the cyanea; the umbrella of this huge jellyfish can reach 2 meters in diameter. The central part of the umbrella is yellowish and the edges are dark red. These jellyfish shimmer with a faint greenish color. The mouth opening is surrounded by sixteen wide oral lobes, crimson-red in color. Cyaneas have long tentacles up to 20-40 meters, light pink in color. When the cyanea spreads its tentacles, the trapping network of them covers 150 square meters.
Under the bell of these jellyfishes, haddocks, cod fry and other fish calmly swim, which under this dome find shelter and food - a variety of microorganisms living on the body of the jellyfish.
If a person touches the tentacles of cyanea, he will experience pain that goes away only after 40 minutes, in addition, quite serious lesions can occur on the skin.
Equorea jellyfish
Among the jellyfish there are also luminous representatives. If a large number of jellyfish accumulate in the water, at night it seems that green or blue balls light up from time to time.
Equorean jellyfish live on the Pacific coast of Russia, as well as on the Atlantic coast of the United States. The glow of these jellyfish makes the waves seem to be on fire. And in tropical and moderately cold waters, luminous pelagia of the nightglow live.
Under the “dome” of a jellyfish, fry of various fish can live. There is an interesting relationship between jellyfish and small fish. When immersed in water, you can see small horse mackerel swimming next to the cornet jellyfish. When divers approach the fish, they instantly hide under the dome of the jellyfish, through which their bodies can be distinguished. The fry do not touch the stinging cells located on the tentacles of jellyfish, so jellyfish for them are a reliable shelter from numerous predators. But some careless fry nevertheless become victims of stinging cells, in which case the jellyfish calmly digests them.
Medusa cannonball
The cannonball jellyfish lives along the east coast of the United States to Brazil. It got its name because of its unusual shape, perfectly smooth and round, like a cannonball. In Asian countries, these jellyfish are widely used in folk medicine. It is believed that they can cure lung disease, arthritis, and lower blood pressure.
Olindias formosa
This rare view jellyfish are found off the coast of Brazil, Argentina, and Japan. Characteristic of these jellyfish is hovering at shallow depths. When the jellyfish is in this state, its tentacles are concentrated under the cap. Due to the small number this type does not pose a danger to people, but we should not forget that they can leave very severe burns.
Portuguese man of war
This amazing creature differs from all jellyfish in that it consists of many jellyfish individuals. It has a gas bubble that floats on the surface of the water, which allows it to absorb air. Tentacles Portuguese man-of-war when extended they can reach 50 meters.
Purple striped jellyfish
This type of jellyfish can be found in Monterrey Bay. They are not yet well studied. This jellyfish has quite big sizes and can cause serious burns to humans. Stripes and rich colors appear in jellyfish as they age. Along with warm currents, the jellyfish can also migrate to the shores of Southern California. This was especially noticeable in 2012, when burns of jellyfish (black sea nettle and purple striped) were received by 130 people.
Mediterranean or jellyfish fried egg
This amazing creature really resembles a fried egg, or poached egg. Jellyfish live in the Mediterranean, Adriatic and Aegean Seas. Her important feature it is believed that she can move independently without relying on waves.
Darth Vader or Narcomedusa
This type of jellyfish was discovered in the Arctic. This happened quite recently. In addition to such an interesting and at the same time terrifying appearance, the jellyfish has 4 tentacles and 12 stomach pouches. While swimming, the tentacles are pulled forward to better reach their prey.
blue jellyfish
The blue jellyfish has very stinging tentacles. It has been discovered off the coast of Scotland, in the North Sea and in the Irish Sea. The average transverse diameter of this jellyfish is 15 centimeters. Color varies from dark blue to bright blue.
Porpit porpit
It's not really a jellyfish. This creature is more commonly known as the blue button. The porpet lives on the surface of the ocean and consists of two parts: a hard golden-brown float and hydroid colonies, which in appearance are very similar to the tentacles of a jellyfish. Porpita can easily be confused with a jellyfish.
Diplulmaris Antarctica
This magnificent creature lives in the deep waters of Antarctica and has four bright orange tentacles as well as white tentacles. The small white dots on the jellyfish are side-spreads. They live inside the jellyfish and sometimes even feed on it.
Black sea nettle
The black sea nettle is a giant bell-shaped jellyfish with a diameter of 3 feet. An adult can reach 5 meters and have 24 tentacles. This type of jellyfish was discovered in the waters Pacific Ocean. they are carnivores. They prefer larvae, plankton, and other jellyfish as food.
Jellyfish are very common and the most amazing view living creatures inhabiting the seas and oceans. You can admire them endlessly. What types of jellyfish are there, where they live, what they look like, read in this article.
General information about jellyfish
They belong to the coelenterates and are part of their life cycle, which comes in two stages: asexual and sexual. Adult jellyfish are dioecious and reproduce sexually. The role of the male is to sweep reproductive products into the water, which can immediately enter the corresponding organs of the female or be fertilized directly in the water. It depends on the type of jellyfish. The emerging larvae are called planulae.
They have the ability to exhibit phototaxis, that is, they move towards a light source. Obviously, they need to stay in the water for some time, and not immediately fall to the bottom. The freely mobile life of planulas does not last long, about a week. After this, they begin to settle to the very bottom, where they attach to the substrate. Here they are transformed into a polyp or scyphistoma, the reproduction of which occurs by budding.
This is called asexual reproduction, which can continue indefinitely until conditions are favorable for the formation of jellyfish. Gradually, the body of the polyp acquires transverse constrictions, then the process of strobilation occurs and the formation of young disc jellyfish - ethers.
They are most of the plankton. Subsequently, they mature and become adult jellyfish. Thus, for asexual reproduction - budding, the water temperature may be low. But, having overcome a certain temperature barrier, dioecious jellyfish are formed.
Class of hydroid jellyfish
Coelenterates include solitary or colonial aquatic inhabitants. Almost all of them are predators. Their food is plankton, larvae and fry of fish. There are ten thousand species of coelenterate jellyfish. They are divided into classes: hydroid, scyphoid, and the first two classes are usually combined into a subspecies of jellyfish.
Hydroid coelenterate jellyfish are characteristic representatives of freshwater polyps. Their usual habitats are lakes, ponds and rivers. The body has a cylindrical shape and the sole is attached to the substrate. The opposite end is crowned with a mouth with tentacles located around it. Fertilization occurs inside the body. If a hydra is cut into many pieces or turned out the other way, it will continue to grow and live. The length of her body is green or brown color reaches one centimeter. Hydra does not live long, only one year.
They are free-floating and come in different sizes. The size of some species is only a few millimeters, while others are two to three meters. An example is cyanea. Its tentacles can stretch up to twenty meters in length. The polyp is poorly developed or completely absent. The intestinal cavity is divided into chambers by partitions.
Scyphoid jellyfish can live up to several months. About two hundred species live in temperate and tropical waters of the World Ocean. There are jellyfish that people eat. These are cornerota and aurelia, they are salted. Many species of scyphoid jellyfish cause burns and reddening of the body if touched. For example, chirodrofus even causes fatal burns in humans.
Jellyfish Aurelia eared
There are different types of jellyfish. A photo of one of them is presented to your attention. This is a scyphoid eared one. Her breathing is carried out throughout her transparent and gelatinous body, in which there are twenty-four eyes. Sensitive bodies called rhopalia are located along the entire perimeter of the body. They perceive impulses environment. It could be the light.
The jellyfish eats food and removes its remains from the body through the mouth opening, around which four oral lobes are located. They contain a burning substance that serves as a defense for the jellyfish and helps it obtain food. Aurelia is not adapted to life on land, as it consists of water.
Medusa Cornerot
It is popularly called the "Umbrella". The habitat of the jellyfish is the Black, Azov and Baltic seas. Cornerot fascinates with its beauty. The body of the jellyfish is translucent with a blue or purple edging, reminiscent of a lampshade or umbrella. Its peculiarity is that most often it swims on its side and has no mouth. Instead, small diameter holes are scattered on the blades through which it feeds. Cornerot lives and reproduces in water columns at great depths. If you accidentally come into contact with a jellyfish, you can get burned.
Unusual habitat
Scientists from Israel have proven that freshwater jellyfish are found in lakes in the Golan Heights. The children saw them for the first time. Then individual specimens were placed in a bottle and given to Professor Gofin. He studied them carefully in the laboratory. It turned out that this was a local colony of one of the freshwater hydroid jellyfish, which were described in England back in 1880. Then these jellyfish were discovered in a pool of water tropical plants. According to the professor, the jellyfish's mouth is surrounded by numerous stinging cells, with which it catches planktonic organisms. These jellyfish are not dangerous to humans.
Freshwater jellyfish
These coelenterate inhabitants inhabit the waters only of seas and oceans. But, there is one exception called the Amazon freshwater jellyfish. Its habitat is South America, namely the swimming pool large river on the mainland - the Amazon. Hence the name. Today, this species has spread everywhere, quite by accident, during the transportation of fish from the seas and oceans. The jellyfish is very small, reaching only two centimeters in diameter. Now she inhabits the slow, calm and standing water, dams, canals. The food is zooplankton.
The largest jellyfish
This is cyanea or lion's mane. There are different types of jellyfish in nature, but this one is special. After all, it was Conan Doyle who described it in his story. This is a very large jellyfish, the umbrella of which reaches two meters in diameter, and the tentacles reach twenty. They look like a raspberry-red tangled ball.
In the central part the umbrella is yellowish, and its edges are dark red. The lower part of the dome is endowed with a mouth opening, around which there are sixteen large folded oral lobes. They hang down like curtains. Cyanea moves very slowly, mainly on the surface of the water. It is an active predator, feeding on planktonic organisms and small jellyfish. Habitat: cold waters. Occurs frequently, but is not dangerous. The resulting burns are not fatal, but can cause painful redness.
Jellyfish "Purple Sting"
This species is distributed in the World Ocean with warm and temperate waters: it is found in the Mediterranean and in the Atlantic and Pacific oceans. These types of jellyfish usually live far from the coast. But sometimes they can form schools in coastal waters, and can be found in large numbers on the beaches. Jellyfish are not only They are golden yellow or yellow-brown, depending on their habitat.
Jellyfish Compass
These types of jellyfish chose coastal waters as their place of residence. Mediterranean Sea and one of the oceans - the Atlantic. They live off the coast of Turkey and the United Kingdom. These are quite large jellyfish, their diameter reaches thirty centimeters. They have twenty-four tentacles, which are arranged in groups of three each. The body color is yellowish-white with a brown tint, and its shape resembles a saucer-bell, which has thirty-two lobes, which are colored brown at the edges.
The upper surface of the bell has sixteen brown V-shaped rays. The lower part of the bell is the location of the mouth opening, surrounded by four tentacles. These Their poison is potent and often leads to the formation of wounds that are very painful and take a long time to heal.
And it is one of the species of sea cnidarians. Looking at this beautiful jellyfish, you would never think that it is one of the ten most dangerous creatures on the planet.
Why her called a sea wasp? Yes, because it “stings” and the affected area swells and turns red, like an insect bite. However, it is believed that more people die from its bite than from attacks.
sea wasp not the largest jellyfish in your class. Its dome reaches the size of a basketball, which is 45 cm. The weight of the largest individual is 3 kg. The color of the jellyfish is transparent with a slight bluish tint, this is due to the fact that it itself consists of 98% water.
The shape of the dome is similar to a round cube, with a bunch of tentacles extending from each corner. Each of the 60 is covered with many stinging cells, which are filled deadly poison. They respond to chemical signals of a protein nature.
At rest, the tentacles are small - 15 cm, and at the time of hunting they become thinner and stretch up to 3 meters. The decisive lethal factor in an attack is the overall size of the stinging tentacles.
If it exceeds 260 cm, then death occurs within a few minutes. The amount of poison in one is enough for 60 people to say goodbye to life in three minutes. The danger of the Australian sea wasp is that it is practically invisible in the water, so encountering it occurs suddenly.
The biggest mystery for zoologists is the 24 eyes of this jellyfish. At each corner of the dome, there are six of them: four of which react to the image, and the remaining two react to light.
It is not clear why the jellyfish needs them in such quantities and where the information received is sent. After all, she lacks not only a brain, but even a primitive central nervous system. The box jellyfish also lacks respiratory, circulatory and excretory systems.
Sea wasp lives off the coast of Northern Australia and in the west in the Indian Pacific. More recently, jellyfish were discovered on the coast South-East Asia. Tourists visiting Vietnam, Thailand, Indonesia and Malaysia need to be careful when swimming in open waters.
Character and lifestyle of the sea wasp
The sea wasp is an active, dangerous predator. At the same time, she does not chase prey, but freezes motionless, but at the slightest touch the victim receives her portion of poison. Jellyfish, unlike or, stings more than once, but uses a whole series of “bites”. Gradually increasing the dose of poison to the lethal level.
Australian sea wasp An excellent swimmer, she easily turns and maneuvers between algae and in coral thickets, developing speeds of up to 6 m/min.
Jellyfish become more active at dusk, rising to the surface in search of food. During the day, they lie on a warm sandy bottom, in shallow water and avoid coral reefs.
These box jellyfish pose a great threat to human life, but they themselves never attack him, but rather even prefer to swim away. Sea wasp bite a person can only accidentally, more often the victims are divers without special suits. Upon contact with poison, the skin immediately turns red, swells, and unbearable pain is felt. The cause of death is most often cardiac arrest.
It is very difficult to provide timely assistance in the water, but none of the available methods work on the shore either. Neither vinegar nor water and cola will help. It is strictly forbidden to bandage the affected area.
The only thing that can be done is to administer antitoxic serum and urgently take the victim to the hospital. But even then, death can occur within 24 hours after contact. Burn site sea wasp looks like a ball of red, it can be seen on photo.
The surprising thing is that you can even be poisoned by the poison of a dead sea wasp. It retains its toxic properties for a whole week. The cause of a burn can even be the poison of a dried tentacle after it gets wet.
Off the coast of Australia in large quantities jellyfish appear in summer months(November - April). To protect vacationers from sea wasps, public beaches are surrounded with special nets through which this dangerous jellyfish cannot swim. Installed in unprotected places special signs, which warn tourists about the danger.
Sea wasp nutrition
Eating sea wasps small fish and bottom organisms. Their favorite delicacy is. This is her way of hunting. The sea wasp extends its elongated tentacles and freezes. Prey swims by, touches them, and the poison immediately enters its body. She dies, and the jellyfish catches her and swallows her.
These sea wasps dangerous for all living organisms except marine ones. She, the only one on the planet, is protected from them. The poison simply has no effect on her. And he eats this type of jellyfish with pleasure.
Reproduction and lifespan
The breeding season for jellyfish begins in the summer months, when they gather in whole “swarms” and swim to the shores. Many beaches in Australia are closed during this time. The process of reproduction in the sea wasp itself is interesting. It combines several pathways: sexual, budding and division.
The male releases a portion of sperm directly into the water, not far from the swimming female. The latter swallows it and the development of larvae occurs in the body, which certain time, settling on the seabed, they attach to shells, stones or other underwater objects.
After a few days it becomes a polyp. It gradually reproduces by budding and grows a young jellyfish. When the sea wasp becomes independent, it breaks away and swims away. The polyp itself then dies instantly.
Jellyfish reproduce once in their lives, after which they die. Their average lifespan is 6-7 months. During this time, their growth does not stop. Sea wasps They are not on the verge of extinction as a species and their abundance leaves no doubt that they will not appear on the pages of the Red Book.
Since ancient times, people have known strange shapeless sea animals, to which they gave the name “jellyfish” by analogy with the mythological ancient Greek goddess Medusa the Gorgon. The hair of this goddess was a moving tuft of snakes. 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 freshwater species of these marine inhabitants is known. Each species occupies a habitat limited to one body of water and will never be found in another sea or ocean. Jellyfish are either cold-water or heat-loving; 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 into the depths in search of food. The horizontal movement of jellyfish is passive in nature - 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 concentrations of 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 “flower cap” jellyfish (Olindias formosa) looks almost transparent Types of jellyfish
More than 200 species of jellyfish are known in nature. Despite the primitiveness of the structure, they are very diverse. Their sizes range from 1 to 200 cm in diameter. The largest jellyfish is the lion's mane (cyanea). Some of its specimens can weigh up to 1 ton and have tentacles up to 35 m long.
Jellyfish are shaped like a disk, an umbrella, or a dome. Most jellyfish have a transparent body, sometimes with bluish, milky, or yellowish tints. But not all species are so inconspicuous; among them there are truly beautiful, bright colors: red, pink, yellow, purple, speckled and striped. There are no green jellyfish in nature.
Species such as Equorea, Pelagia nocturna, and Rathkea can glow in the dark, causing a phenomenon called bioluminescence. Deep-sea jellyfish emit red light, while those floating near the surface emit blue light. There is a special type of jellyfish (staurojellyfish) that hardly move. They are attached to the ground with a long leg.
The structure of jellyfish
The internal structure and physiology of jellyfish are uniform and primitive. They have one main hallmark– 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 does not have a skeleton; it consists of 98% water. When thrown ashore, the jellyfish is unable to move and dries up instantly. Its consistency is similar to jelly, which is why the British called it “jelly fish.”
Body tissues have only two layers, which are connected to each other by an adhesive substance and perform different functions. The cells of the outer layer (ectoderm) are “responsible” for movement, reproduction, and are analogues of skin and nerve endings. The cells of the inner layer (endoderm) only digest food.
The outer part of the body of 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 among different types of jellyfish. The umbrella is surrounded by hunting tentacles, which, depending on the species, can be either thick and short or thin, thread-like, and long.
What do jellyfish eat?
Jellyfish are predators; they consume only animal food (crustaceans, fry, small fish, caviar). They are blind and have no senses. Jellyfish hunt passively, catching with their tentacles the edibles that the current brings. The hunting tentacles kill the prey. This is done different ways.
This is the largest jellyfish in the world - the cyanea, or lion's mane (Cyanea capillata), its long tentacles can reach 35 m in length! Some types of jellyfish inject poison into the prey, others glue the prey to the tentacles, and others have sticky threads in which it becomes entangled. The tentacles push the paralyzed victim towards the mouth, through which undigested remains are then expelled. Interestingly, jellyfish living in the depths attract prey with their bright glow.
How do jellyfish reproduce?
Jellyfish have vegetative (asexual) and sexual reproduction. Externally, males are no different from females. Sperm and eggs are released through the mouth into the water, where fertilization occurs. After this, the 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 reproduce by budding. Gradually, the upper parts of the polyp separate and float away; these are actually young jellyfish that will grow and develop.
Some species of jellyfish do not have a polyp stage. Young individuals are immediately formed from the planula. There are also species in which polyps are formed in the gonads, from which small jellyfish are born. Each egg cell in jellyfish produces several individuals.
Vitality of jellyfish
Although jellyfish do not live long - from several months to 2-3 years, their numbers are restored very quickly even after various disasters. Their reproduction rate is very high. Jellyfish quickly restore lost body parts. Even if they are cut in half, two new individuals are formed from the halves.
Interestingly, if such an operation is performed in at different ages jellyfish, then an individual of the corresponding developmental stage grows from the tissues. If you divide the larva, then two larvae will grow, and from the adult parts - jellyfish of the appropriate age.
Jellyfish swimming upside down Jellyfish and people
Some types of jellyfish pose a danger to humans. They can be roughly divided into two groups. Some cause allergies, the poison of others affects nervous system and can cause serious muscle and heart problems and, in some cases, death.
To avoid putting yourself in danger, you should avoid touching jellyfish, both living and dead. In case of a burn, you should wash the injured area with water, or better yet, a vinegar solution. If the pain does not subside and there are complications, you should immediately call a doctor.
