Jellyfish facts: poisonous, luminous, the largest jellyfish in the world. Interesting facts about jellyfish Why jellyfish
Over the past few years, Tunisia has become extremely popular among Russian tourists. This is explained by the fact that holidays in Tunisia are quite inexpensive and can compete even with the resorts of Egypt and Turkey in terms of prices and variety of entertainment infrastructure. In addition, on the territory of this African country there are a great many natural, cultural and historical monuments.
Basically, the climate of Tunisia is mild, even in winter, so you can feel comfortable here at any time of the year. Holiday seasons in Tunisia are conventionally divided into two periods - summer and winter. In summer, when the air temperature is about 25-30ºС and the water temperature is 26-28ºС, travelers go to the coast. In winter, when the air warms up no more than 12ºС, and the water - no more than 15ºС, lovers of the famous thalassotherapy, spa treatments and Tunisian hammams come to the country.
If you still prefer to bask in the hot rays of the sun and swim in the warm sea, then before planning a trip to the resorts of Tunisia, you should pay attention to such an unpleasant fact as the jellyfish season in Tunisia.
Features of the jellyfish season in Tunisia
As a rule, the largest concentration of jellyfish off the coast of beaches is observed around mid-August and lasts about a couple of weeks. However, the jellyfish season in Tunisia does not happen every year, and in to a greater extent depends on weather conditions. The more the water near the shore warms up, the more likely it is that in the near future the entrance to the sea will become quite unpleasant for swimmers.
Some hotels in Tunisia that have their own beach often fence it with a special net that traps jellyfish and prevents them from ruining the holiday of swimmers.
Is the jellyfish season dangerous in Tunisia?
In general, jellyfish are not dangerous to human life, but their burns can cause some trouble for people with sensitive skin, as well as for those who are susceptible to various allergic reactions. Despite the fact that even representatives of local population, nevertheless, when going to Tunisia during the jellyfish season, you should always have special medications from burns. It is not always possible to quickly find a pharmacy, even near the best beaches in Tunisia.
If you are unlucky enough to get stung by a jellyfish, never wash the affected skin with water or scratch it. It is best to wipe the area with vinegar, alcohol, or alcohol-based medicinal products, and then apply a gel or ointment that relieves swelling and itching. If such remedies are not available, apply a tomato slice to the bite site. If an allergic reaction occurs (most often this happens in young children), you should immediately consult a doctor.
The jellyfish season in Tunisia is most dangerous in the areas of Hammamet, Monastir and Sousse - the highest concentration of jellyfish is observed here during this period. Found off the coast of Tunisia the following types jellyfish: cotylorhiza, charibra, chryozora, pink sea anemone and black jellyfish. The last two species are the most poisonous, but also the least common. In general these sea creatures can be found not only in August-September. Single specimens periodically appear off the coast, regardless of what sea in Tunisia is on at the moment- cool or warm.
How to avoid meeting jellyfish in Tunisia?
When is the best time to go to Tunisia so as not to spoil your beach holiday?
The jellyfish season in Tunisia is a non-periodic phenomenon, but it is best to choose June, July and early August, then the second half of September and early October. If your trip is scheduled for the end of summer - beginning of autumn, be careful when swimming and exercise maximum caution so that you do not spend the remaining days before the end of your vacation on the shore, or, even worse, in a hotel room or local hospital.
Have a nice holiday in Tunisia!
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Jellyfish of the Sea of Azov
In the seas of our country there are two types of jellyfish that can leave burns. , or eared jellyfish, can grow up to 40 cm in diameter. These are round jellyfish with four rings in the center of the cap. Burns from this jellyfish are very mild, but if the toxins get into the eyes (usually through the hands), they will cause a burn to the eye that will take several days to resolve. more poisonous jellyfish. It has large tentacles, and the rim of the cap is colored purple or blue. A meeting with her always ends in burns. Irritation usually goes away in 1-3 days.
Medusa is one of the most ancient inhabitants of the Earth. Having appeared more than 650 million years ago, they have changed little. Almost all jellyfish are jelly-like organisms containing more than 95% water. Only muscle fibers make the jellyfish a complete organism. Jellyfish lack the organs found in many other organisms. But there is a stomach directly connected to the mouth. The mouth opening, in turn, is also a waste outlet. In many jellyfish, the mouth opening and stomach serve not only digestive function, but also the movement function. The jellyfish fills its stomach with water and pushes it out. Thus, she moves in the direction she needs.
Jellyfish are an integral part of all more or less salty bodies of water. There are many species of jellyfish, found both in shallow waters and at depths of more than 10,000 meters; both poisonous and completely harmless; both huge and very small; thermophilic and found among the ice of the Arctic.
There are three types of jellyfish in the Black Sea: Aurelia, Cornerot, and Mnemiopsis. All Black Sea jellyfish are not dangerous. But they bring trouble to both vacationers and fishermen.
Rhizostoma pulmo common name
jellyfish cornermouth
Fishermen call it alicon or alikona. This is the most famous Black Sea jellyfish. Not because it occurs more often than others, but because it stings more often than others.
Carnerot can be recognized by its large cap, up to 50 cm in diameter, and large fleshy root-like outgrowths. These are not tentacles. Cornerots have no tentacles; their oral lobes branch, forming numerous folds fused together. The ends of the oral lobes do not form folds, but end in root-like outgrowths.
Cornerot is a predator that prefers small fish, worms, and small crustaceans. With their poison they paralyze their prey and successfully eat it.
This species is widespread in the Black Sea. Especially large number appears on the coast in the second half of summer. This is far from the most pleasant part of the holiday, but it is not dangerous either. The poison of one cornet is not fatal to humans, and the pain after a burn is not much stronger than that of nettles.
Kornerot is sensitive to changing weather conditions. For example, before a storm, jellyfish move away from the shore and go to the bottom.
Aurelia aurita Aurelia, or eared jellyfish
Aurelia jellyfish
The common name is aurelia or eared aurelia. Fishermen call it sherikh.
Aurelia reaches 40 cm in diameter. The “hat” is translucent, most often colorless, sometimes with a slight shade of blue, pink, and purple.
Aurelia is carnivorous. The diet of Aurelia includes mollusks, crustaceans, larval shells, crustaceans, rotifers, protozoa, and diatoms.
Aurelia's habitat is the coast. Optimal temperature for aurelia 9 - 19 C0. , although it can withstand water temperatures down to -30 C0.
Mnemiopsis leidyi
jellyfish Mnemiopsis
Mnemiopsis is a jellyfish that does not have tentacles or stings. It reaches 10 cm in length and 6 cm in width. This organism has the properties of bioluminescence - the ability to glow.
Sexual maturity of both female and male individuals occurs on the 13th day of life. Mneniopsis is capable of fertilizing itself. Spawning occurs only at night. One individual is capable of producing 8,000 eggs. After fertilization, the embryo is fully formed as a jellyfish at the 20th hour of life.
Mnemiopsis feeds mainly on the eggs of small fish (sprat, etc.) and zooplankton. This organism will continue to consume food even after the stomach is completely full. When the stomach is full, the excess food is expelled as a ball of mucus. If there is no food available, Mnemiopsis can survive for up to three weeks.
Mneniopsis is not native to the Black Sea, but comes from the eastern shores of the USA and the West Indies. The invasion of this species in the Black Sea has caused significant damage to fisheries. Currently, measures are being taken to reduce the number of this species.
Hydroid jellyfish
The class Hydroids - Hydrozoa - includes about 2800 species. In the life cycle of most hydroid polyps (Hydrozoa), as well as most coelenterates: scyphozoans (Scyphozoa) and box jellyfish (Cubozoa), the sexual phase of the life cycle, the jellyfish, dominates. This group of jellyfish has its own distinctive features.
The digestive system of hydroids is represented by a gastric cavity that has no partitions. The pharynx is missing. The ectoderm and endoderm meet at the edge of the mouth opening.
Digestive juices are secreted into the intestinal cavity of the hydra by the glandular cells of the endoderm.
Tentacles hang along the edges of the umbrella, maybe 4, 8, 16, rarely more. At the base of the tentacles or between them there are sensory organs. On the inner side of the edge of the umbrella, the ectoderm forms an annular protrusion, the so-called sail or velum.
Reproductive products are formed in the ectoderm. The nervous system is diffuse (scattered throughout the body). Nerve cells - neurons - form nerve networks and plexuses.
The ectoderm of the hydra includes epithelial-muscular, stinging, intermediate, nerve and pigment cells.
When the hydra body regenerates, new cells are formed from unspecialized intermediate cells.
The hydroid class unites, along with hydras, a large number of species of marine colonial polyps. Marine hydroids lead an attached lifestyle. Their colonies look like small bushes.
The presence of hydrode jellyfish in the Black Sea has not yet been discovered.
Why are jellyfish dangerous?
Jellyfish are considered the most ancient inhabitants of our planet, they are about 650 million years old, and during this time they have undergone virtually no changes and remained in the same form as millions of years ago. Jellyfish are dome-shaped, they consist of 95% water, and the presence muscle fibers makes the jellyfish look like jelly. The jellyfish does not have organs as such, but there is a hole into which food enters and is processed there, and the final result of processing comes out through that same hole. Jellyfish are absolutely perfect different sizes and they live both in shallow water and in great depths, jellyfish can live both in warm waters and in very cold ones, they are even found near the ice of the Arctic.
Why do jellyfish sting?
The body of a jellyfish is covered with special cells that inject toxins into everything they come into contact with. Most of the stinging cells are on the tentacles of the jellyfish and the rim of its cap.
Jellyfish that live in the Black and Azov Seas do not pose a threat to human life. The stung area quickly turns red. Most people just feel uncomfortable because of this. But experts still recommend immediately getting out of the water and onto the shore.
Jellyfish burn
A jellyfish sting can cause painful shock.
For allergy sufferers, children, the elderly, and people with cardiovascular disease, a reaction to a jellyfish sting can be hazardous to health. The stung person feels severe pain, it radiates to the nearest joints, and then spreads to the whole body. Shock may cause a person to stop breathing. In the seas of our country there are jellyfish with such strong toxins no, but in the seas southeast asia there are plenty of them.
First aid
First aid for a jellyfish sting or burn: how to treat burns and jellyfish stings
The stung area must be rid of jellyfish tentacles and poisonous cells (rinse with water). They are not visible to the eye, so prevention should always be carried out. The stung area can be wiped well with a towel or sand.
For burns caused by jellyfish, you need to wash the affected area with salt water. It is not recommended to wash affected areas fresh water, in which burning enzymes can be activated. If you pick up a jellyfish, do not touch your face after that; wash your hands well with soap and water. If your face is burned by a jellyfish, rinse your eyes only with plenty of warm fresh water and consult a doctor for help.
After this, the poison should be neutralized. Burn areas on the body can be wiped with vinegar, this will significantly relieve irritation, you can use a soda solution, ammonia or alcohol.
To speed up recovery, use an anti-inflammatory agent in the form of a gel or ointment (such as lifesaver or others).
The stung area should be protected from sunlight.
Ultraviolet radiation easily burns damaged skin and also causes sunburn.
If a blister appears, an encounter with a jellyfish does not always end only in redness. A jellyfish sting can cause large blisters. First aid will be the same, but be careful not to burst the bubble. To protect the blister from breaking, you should cover it with a bandage.
Sometimes on the beaches you can see how some self-medication enthusiasts rub themselves with jellyfish in the hope of getting rid of rheumatism, radiculitis, and neuralgia. Such “treatment” is unacceptable; it can lead to unpredictable consequences, since the venom of jellyfish has not yet been studied enough.
How to treat a jellyfish burn at home
Tablets and injections for jellyfish stings
Fenistil.
This is a first generation antihistamine. It is recommended to take the capsule and apply a gel of the same name to the burn. This drug simply blocks the body's response to irritants. need three times a day for a week.
Eden.
This is a syrup with a pleasant taste. The drug is a new generation antihistamine. Differs in small amount side effects, which allows patients to use old age and with heart disease.
Diazolin.
This is the most inexpensive antihistamine, which has a large number of side effects. The medicine belongs to the first generation, therefore, it should not be taken by people with heart problems and small children.
Suprastin.
They are classified as first generation antihistamines. This too effective remedy for allergies, with an impressive list of side effects.
Citrine.
Refers to third-generation drugs that do not cause drowsiness and do not in any way affect the state of the cardiovascular system. Analogs of Citrine are Erius, Trexil, Loratadine. These medications can be taken for several months.
Diprospan.
This drug is used by emergency medical technicians to suppress allergic reactions. This is a glucocorticosteroid, which, when administered intramuscularly, quickly enters the bloodstream and immediately relieves all allergy symptoms. This is an emergency drug, so you should not use it yourself.
No-Shpa.
Medopred.
A corticosteroid to quickly relieve symptoms of a severe allergic reaction. Used for Quincke's edema and anaphylactic shock. This drug is used by emergency doctors for emergency care when a person is choking and has swelling of the tongue and larynx. This injection is most often given when stung by a purple jellyfish, the venom of which is very toxic.
The most dangerous poisonous jellyfish
Sea wasp. This jellyfish is extremely dangerous. Among those whom she stung, there were few survivors. She releases enough poison to kill 50 grown men! Found in Australia, prefers shallow areas with reefs and seagrass.
Irukandji. This sea dweller found in the waters of Oceania and Australia. Releases poison from the tip of the tentacle, which is not very painful. Accordingly, the victim ignores the bite. Over time, the poison spreads throughout the body, causing vomiting, nausea, paralysis and back pain. There are few deaths from the sting of this jellyfish, but the consequences can be dire.
Physalia Portuguese man of war. It’s hard not to notice the jellyfish; it has a beautiful dome that shines with all the colors of the rainbow. Found in the Mediterranean Sea, Indian and Pacific Oceans. The bite is not very painful, so the victim continues to bathe. When poison enters the bloodstream, disruptions in the functioning of the respiratory and nervous systems are observed. A person can drown from convulsions and paralysis.
Cross. Found in the Northern part Pacific Ocean. It stings very painfully. If you come into contact with this sea creature, you should get out of the water, as dizziness, nausea, paralysis, and numbness of the limbs may occur. The poison completely leaves the body after 4 days.
Cyanea. Long thin tentacles extend from the dome. When you touch them, you feel a strong burning sensation. There are not many deaths, but the consequences are not the most pleasant. The victim feels weakness, nausea and swelling of the mucous membranes. Jellyfish are rarely found in coastal areas, preferring the depths.
Invasion of jellyfish on Tarkhankut
Invasion of jellyfish Olenevka Invasion of jellyfish Okunevka Invasion of jellyfish Zolotoy Crimea Invasion of jellyfish Donuzlav
Perhaps, almost all tourists who are going on holiday to this African country are concerned about whether there are jellyfish in Tunisia, and if so, where, during what period and in what quantities they are found. It is worth mentioning separately that jellyfish in Tunisia are not poisonous (black ones are dangerous), but their burns are painful. There are mainly white, transparent, and blue jellyfish, and the latter are visible in the water and you can at least swim away from them. For obvious reasons, it’s more difficult with whites. However, if a person is allergic to this group of poisons, a jellyfish burn in some cases can be fatal.
Jellyfish season in Tunisia
The invasion of jellyfish to the Tunisian shores is a seasonal phenomenon. More precisely, in different times they can be found at different resorts. They appear in the water when it warms up as much as possible. The first jellyfish can appear as early as early July, the peak occurs in August, and there are plenty of them until September.
It is impossible not to mention the fact that jellyfish move with the help of currents, so they cannot wash themselves to one shore or another. You need to monitor, firstly, the water temperature, and secondly, the wind direction.
The average water temperature in June is +24 °C, in July and August +28 °C, in September +24 °C. It is impossible to say exactly which shores will have more jellyfish. However, no one has canceled statistical probability.
Jellyfish in Tunisia: when and where
Popular resorts of Tunisia from north to south: Tabarka, Bizerte, Hammamet, Sousse, Monastir, Mahdia, Djerba island.
Statistics say that in May and October, jellyfish usually occupy the northern coast of Tunisia. In June they can be found in the waters of the island of Djerba. July jellyfish like Mahdia, but there are not many of them, as they are carried by the current. Jellyfish in Tunisia in August and September are a real disaster for vacationers in the resorts of Monastir, Hammamet and Sousse. There are especially many jellyfish in these areas in August, this is the hottest period. Again, judging by the reviews, it doesn’t happen every once in a while: for example, in August Hammamet experiences an invasion of jellyfish, and in neighboring Sousse they are not visible at all.
The main thing to remember: if the water is cool, there are few or no jellyfish. For example, in Tabarka the water is always colder, which is why there are almost no jellyfish. On the other hand, this resort has a deep sea and entering the water is not always comfortable, so you can’t swim with children.
What to do if you are burned by a jellyfish
The most common way to deal with a burn is to immediately rub it with tomato pulp. Any acidic solution will do, including regular table vinegar. The acid decomposes the poison and partially relieves pain. The Tunisians themselves use dry sand and salt water.
Rinse the burn running water is pointless and even dangerous: the affected area will increase, as the water activates the stinging cells.
If you are going to Tunisia during jellyfish season with children, limit your kids' exposure to water. It would be wiser to swim in the hotel pool.
In your travel first aid kit you should take a product that stimulates tissue regeneration (ointment, spray), as well as an antihistamine. A doctor who knows how to quickly deal with a burn should be assigned to the hotel.
Jellyfish are a class of multicellular invertebrates that hunt and kill their victims using tentacles.
These beautiful exotic creatures can only survive in salt water, therefore, their habitat is oceans, seas and in some cases cut off from " big water» lagoons coral islands. Some of the species love cool water, others - warm, others live only in the upper layers, and others - only at the bottom.
It is interesting that the representatives of the animal world in question belong to the same group as... corals. Both of these classes of creatures belong to the coelenterates.
Jellyfish are loners. They do not transmit signals to their “relatives” in any way, even if they are swept into a large pile by the current.
Their name was given to them in the mid-18th century by Carl Linnaeus, who noticed their similarity to the head of the famous character of ancient Greek myths - the Gorgon Medusa.
This is an amazing animal 98% consists of water, therefore, its body is almost transparent, similar to a dome, umbrella or disk made of jelly. And the “dome” moves due to muscle contraction.
Tentacles
There are tentacles along the edges of the creature. They are very different different types: short and thick are possible, long and thin are possible; their number ranges from four to four hundred (the number of tentacles is always a multiple of four, because these animals have an inherent radial symmetry).
Tentacles are built from containing poisonous substances of stinging cells and are needed for movement, hunting and holding prey. Fun fact: even dead jellyfish can bite for about two weeks. Certain types of jellyfish are extremely dangerous for humans. For example, an animal called the Sea Wasp can poison six dozen people in a couple of minutes.
From above the animal’s body is smooth and dome-shaped, and from below it looks like an empty bag. In the middle below is the mouth opening. It can also be different: in some individuals it looks like a pipe, in others it looks like a club, in others it is wide. Undigested food remains are also removed through the mouth.
Growth and development
Jellyfish increase in size throughout their lives, and their final size depends on the species. There are tiny ones, no longer than a couple of millimeters, but there are giants larger than forty meters(this is the length of the tentacles). Cyanea - largest representative, lives in the North Atlantic.
These inhabitants of the sea no brain and sense organs, but there are light-sensitive cells that help them distinguish between darkness and light (they do not see objects). Some specimens can glow in the dark. Animals living in the depths are usually red, and those living near the surface of the water are blue.
Internal structure
The internal structure of animals is very simple. They consist of two layers:
- The outer ectoderm, which acts as a kind of skin and muscle, contains the rudiments of nerves and germ cells.
- Internal endoderm, which only digests food.
Jellyfish have an amazing ability to regenerate: even if you cut an animal into halves, two similar individuals will grow from them.
Classification
- Hydroids or Hydrozoa(organisms that live only in waters that constantly contain absorbed oxygen). Relatively small (1 to 3 cm), transparent animals; four tentacles, a long mouth resembling a tube. The most famous creature of this class is Turritopsis nutricula. This the only thing known to science biologically immortal being. Having aged, she sits on seabed and transforms into a polyp, from which new individuals then grow. This class also includes a very dangerous animal called the Cross. It is tiny (the largest specimens reach about 4 cm), but if it bites a person, the victim will have serious and very long-term health problems.
- Box jellyfish (Cubozoa). This class is so named because their umbrella is not oval, but cubic. They differ from other representatives by their developed nervous system. They can swim at speeds of up to six meters per minute and adjust direction with ease. However, they are also the most dangerous for people: some individuals can even kill a careless swimmer. The most poisonous representative of cnidarians on the planet, the Sea Wasp, is a representative of this class.
Among all the creatures on the planet, jellyfish are one of the most ancient. Scientists claim that they lived in water spaces hundreds of millions of years ago. These creatures are found both in the seas and oceans. Are different appearance, because some are attractive, while others, to put it mildly, are repulsive. Some of them are harmless, but some carry hidden threat so we collected everything interesting facts about jellyfish and combined them into one list.
1. The largest jellyfish is called the Arctic giant and its size is truly impressive. It was possible to find an individual whose dome diameter is almost 2.5 meters, and the length of the entire body, including tentacles, is over 35 meters.
2. It has long been believed that fish are soothing, so people often buy aquariums for themselves at home and admire the inhabitants of the seas, feeding them. In Japan, jellyfish are bred for the same purpose, because researchers in this country have found that their monotonous, smooth movements completely help strengthen the nervous system.
3. Interesting fact about jellyfish for children. Their largest concentration is located in the lake of the same name on the Rocky Archipelago. According to preliminary estimates, there are more than two million individuals there, and this despite the fact that the lake itself is 450 meters long and only 170 wide.
4. The creature does not have lungs; it captures oxygen mixed with water with its entire body. At the same time, the jellyfish also does not have a brain, but has two nervous systems and two dozen eyes.
5. Among the most interesting facts about jellyfish is the box jellyfish and its capabilities. The creature can reach speeds of up to two meters per second and at the same time has a deadly powerful poison. Even the slightest touch to her is fatal, and the total amount of poison in her body is enough to send at least fifty people to the next world.
6. Despite the simplicity of their body structure, jellyfish are capable of movement. They swallow some of the water into themselves and then push it back out. But this happens extremely rarely; most often they prefer to follow the flow, completely inactive.
7. Jellyfish are regularly used in medicine. Back in the Middle Ages, it was discovered that a separate part of their body, called the cornet, has a laxative property. Nowadays, the poison of these creatures is actively used, because it makes medications more effective, which helps normalize blood pressure.
8. Life cycle jellyfish is unique. It begins with eggs, from which planulae are born; they resemble a ciliate shoe enlarged thousands of times, which drifts in the water surface until it encounters something solid on its way, be it a reef, a rock, or maybe the bottom. Having attached to it, it forms a polyp, which gradually grows and forms into something more reminiscent of a jelly-like creature. Sometimes after a month, and sometimes after a year, the changed polyp detaches and the jellyfish appears before the world.
9. Any animal known to possess poison, as a rule, infects its victim through a bite. But jellyfish are a clear exception, because for this they have special organs called nematocysts. Feeling threatened, they stimulate them with such force that they literally explode, striking the enemy's body with hundreds of drops of deadly poison.
10. There is an assumption that one of the types of these creatures is immortal. Scientists have been able to establish that Turritopsis dornii, already fully grown, can return to the polyp state and, in theory, can do this indefinitely. However, this was only verified in the laboratory, because in reality real life they are either eaten or sooner or later washed up on the shore.