Blue jellyfish. Types of jellyfish
Jellyfish are animals that everyone associates with something shapeless and infinitely primitive, but their lifestyle and physiology are not as simple as it seems at first glance. The word "jellyfish" usually means animals from the Scyphoid class and representatives of the Trachilid order from the Hydroid class of the intestinal type. At the same time, in the scientific community, this word has a broader interpretation - zoologists use this term to designate any mobile forms of intestinal animals. Thus, jellyfish are closely related to mobile types of intestinal (siphonophores, sea boats) and sessile ones - corals, sea anemones, hydras. In total, there are over 200 species of jellyfish in the world.
Scyphoid jellyfish rhizostoma, or cornerot (Rhizostoma pulmo).
Because of their primitiveness, jellyfish are characterized by the uniformity of physiology and internal structure, but at the same time they are distinguished by an amazing variety of colors and appearance, unexpected for such simple animals. One of the main distinguishing features of jellyfish is radial symmetry. This type of symmetry is characteristic of some marine animals, but in general it is not so common in the animal world. Due to radial symmetry, the number of paired organs in the body of jellyfish is always a multiple of 4.
The umbrella of this jellyfish is divided into blades, the number of which is always a multiple of 4.
Jellyfish are so primitive that there are no differentiated organs in their body, and the tissues of the body consist of only two layers: the outer (ectoderm) and the inner (endoderm), connected by a sticky substance - mesoglea. However, the cells of these layers are specialized to perform different functions. For example, ectoderm cells perform an integumentary function (skin analog), motor (muscle analog), here are special sensitive cells, which are the rudiments of the nervous system and special germ cells that form reproductive organs in adult jellyfish. But the cells of the endoderm are only engaged in the digestion of food, for this they secrete enzymes that digest the prey.
Due to the highly developed colorless mesoglea, the body of the flower cap jellyfish (Olindias formosa) looks almost transparent.
The body of jellyfish is shaped like an umbrella, disk or dome. Top part the body (it can be called external) is smooth and more or less convex, and the lower (it can be conditionally called internal) shape resembles a bag. The inner cavity of this sac is both an engine and a stomach. In the middle of the lower part of the dome, the jellyfish have a mouth. Its structure is very different from different types: in some jellyfish, the mouth has the shape of an elongated proboscis or tube, sometimes very long, in others, short and wide oral lobes are located on the sides of the mouth, in others, instead of lobes, there are short club-shaped oral tentacles.
This chic crown is formed by the mouth tentacles of the cotylorhiza tuberculata jellyfish.
Trapping tentacles are located along the edges of the umbrella, in some species they can be relatively short and dense, in others - thin, long, filiform. The number of tentacles can vary from four to several hundred.
Long-eared jellyfish's tentacles ( Aurelia aurita) are relatively short and very thin.
In some species of jellyfish, these tentacles are modified and turned into organs of balance. Such organs have the form of a tube-stalk, at the end of which there is a bag or vial with a calcareous stone - statolith. When the jellyfish changes direction, the statolith shifts and affects the sensitive hairs, from which the signal is transmitted to the nervous system. The nervous system of jellyfish is extremely primitive, these animals have neither a brain nor sensory organs, but there are groups of light-sensitive cells - eyes, so jellyfish distinguish between light and dark, but they, of course, cannot see objects.
And this jellyfish has thick and long trapping tentacles combined with long and fringed mouthparts.
However, there is one group of jellyfish that completely refutes the usual ideas about these animals - these are stauromedusas. The fact is that stauromedusas do not move at all - this is a rare example of sedentary animals. Sitting jellyfish are radically different in their structure from free-swimming species, at first glance the relationship between these groups of jellyfish seems incredible.
Sedentary jellyfish Cassiopeia (Cassiopea andromeda).
The body of stauromedusa resembles a bowl on a long leg. With this leg, the jellyfish is attached to the ground or algae. The mouth is located in the middle of the bowl, and the edges of the bowl are extended into eight so-called arms. At the end of each "arm" is a bunch of short tentacles, similar to a dandelion.
Sedentary alfalfa jellyfish (Lucernaria bathyphila).
Despite the fact that stauromedusas lead a sedentary lifestyle, if necessary, they can move around. To do this, the jellyfish bends its leg in such a way that its cup leans towards the ground, and then stands on its “hands”, as if performing a headstand, after which the leg comes off and moves a few centimeters, standing on the leg, the jellyfish straightens up. Such movements are carried out very slowly, during the day the jellyfish takes several steps.
This alfalfa shows off the muscular stalk that anchors it to the bottom.
The sizes of jellyfish range from 1 cm to 2 m in diameter, and the length of the tentacles can reach 35 m! The weight of such giants can reach up to a ton!
This is the largest jellyfish in the world - cyanide, or lion's mane (Cyanea capillata), it is her long tentacles that can reach 35 m in length!
Since the tissues of jellyfish are poorly differentiated, their cells do not have color. In most jellyfish, the body is transparent or with a pale milky, bluish, yellowish tinge. This feature is reflected in English name jellyfish - "jelly fish". Indeed, devoid of a skeleton, soft, saturated with moisture (the water content in the body of jellyfish is 98%!), The pale body of jellyfish resembles jelly.
In water, their body retains elasticity due to saturation with moisture, but a jellyfish thrown onto land instantly falls and dries up; on land, jellyfish are not able to make even the slightest movement.
However, not all jellyfish are so nondescript. Among them there are really beautiful views, painted in bright colors - red, pink, purple, yellow. Only green jellyfish do not exist. In some species, the coloration has the appearance of a pattern in the form of small specks or stripes.
Amazing play of colors of scyphoid jellyfish.
But that's not all. Some types of jellyfish (pelagia nightlight, aequorea, ratkey and others) are able to glow in the dark. Interestingly, in deep-sea jellyfish, the emitted light is red, while those that swim close to the surface of the water are blue. This phenomenon is called bioluminescence and underlies the exciting natural phenomenon- night glow of the sea. The glow arises as a result of the decay of a special substance - luciferin, whose name is consonant with the name of the devil, obviously this phenomenon caused awe among the discoverers of bioluminescence. In fairness, it should be said that the glow of water is provided not only by jellyfish, but also by others. marine organisms- small crustaceans (plankton), algae and even ... worms.
The deep-sea scyphoid atoll jellyfish (Atolla vanhoeffeni) is bright red in color and looks like an unearthly creature.
The range of jellyfish covers the entire World Ocean, they are found in all seas except inland ones. Jellyfish live only in salt water, occasionally they can be found in closed lagoons and brackish lakes of coral islands that once separated from the sea. The only freshwater species is the tiny jellyfish kraspedakusta, which was discovered by chance in the pool ... of the London Botanical Society. Jellyfish got into the pool along with aquatic plants brought from the Amazon. Among the jellyfish you will not find pandemic species, that is, those that are found everywhere, usually each species of jellyfish occupies an area limited by any one sea, ocean or bay. Among jellyfish there are heat-loving and cold-water ones; species that prefer to stay near the surface and deep-sea. Deep-sea jellyfish almost never rise to the surface; they swim all their lives in the depths in pitch darkness. Those jellyfish that live near the surface of the sea make vertical migrations - during the day they sink into great depth and rise to the surface at night. Such migrations are associated with the search for food. Also, jellyfish can migrate in a horizontal direction, although they are passive in nature, jellyfish are simply carried by the current over long distances. Jellyfish, being primitive animals, do not contact each other in any way, they can be classified as solitary animals. At the same time, in places rich in food, at the intersection of currents, jellyfish can form large clusters. Sometimes the number of jellyfish increases so much that they literally fill the water space.
Numerous jellyfish make vertical migration in the slightly saline Lake Medusa on about. Palau.
Jellyfish move rather slowly, largely using the auxiliary power of the currents. The movements are provided by thin muscle fibers in the umbrella: contracting, they seem to fold the dome of the jellyfish, while the water contained in the internal cavity (stomach) is pushed outward with force. Thus, a jet stream arises, which pushes the body of the jellyfish forward. Accordingly, jellyfish always move in the direction opposite to the mouth, but they can swim in different directions - horizontally, up and down (as if upside down). The direction of movement and their position in space are determined by the jellyfish with the help of balance organs. Interestingly, if the vials with statoliths are cut off from a jellyfish, its umbrella is less likely to contract. However, in the role of an invalid, a jellyfish is not destined to live long - these animals have excellent tissue regeneration. Due to the primitive structure, all cells in the body of jellyfish are interchangeable, so they quickly heal any wounds. Even if the jellyfish is cut into pieces or the “head” is separated from the lower body, it will restore the missing parts and form two new individuals! Characteristically, the recovery of the head end is faster than the end part. Even more surprising is that if such an operation is carried out on different stages development of a jellyfish, then each time individuals of the appropriate age will be formed - adults will form from an adult jellyfish, only larvae will form from the larval stage, which will continue their development as independent organisms. Thus the tissues of one of the most primitive animals possess the so-called cellular memory and "know" their age.
Medusa swimming upside down.
All jellyfish are predators because they feed exclusively on animal food. However, the prey of most jellyfish are tiny organisms - small crustaceans, fish fry, free-floating fish eggs and just small edible pieces of someone else's prey. Most large species jellyfish can prey on small fish and ... smaller jellyfish. However, jellyfish hunting looks peculiar. Since jellyfish are practically blind and have no other senses, they are unable to detect and pursue prey. They find their food in a passive way, they simply catch with their tentacles the edible trifle that the current brings. Jellyfish catch the touch with the help of trapping tentacles and kill the victim with them. How do primitive helpless "jelly" do this? Jellyfish have powerful weapons - stinging or nettle cells in tentacles. These cells can be of different types: penetrants - the cells look like pointed threads that dig into the body of the victim and inject a paralyzing substance into it; glutinants - threads with a sticky secret that "glue" the victim to the tentacles; Volvents are long sticky threads in which the victim simply gets entangled. The tentacles push the paralyzed victim to the mouth, undigested food residues are also excreted through the mouth. The poisonous secret of jellyfish is so powerful that it affects not only small prey, but also animals much larger than the jellyfish themselves. Deep-sea jellyfish lure prey with a bright glow.
The victim can not get out of this tangle of mouth and trapping tentacles of a jellyfish.
The reproduction of jellyfish is no less interesting than other life processes. In jellyfish, sexual and asexual (vegetative) reproduction is possible. Sexual reproduction includes several stages. Sex cells mature in the gonads of jellyfish, regardless of the season, but in species from temperate waters, reproduction is still confined to the warm period of the year. Jellyfish are separate sexes, males and females outwardly do not differ from each other. The eggs and sperm are released into the water… through the mouth, during external environment fertilization occurs, after which the larva begins to develop. Such a larva is called planula, it is not able to feed and reproduce. A short time planula floats in the water, and then settles to the bottom and attaches to the substrate. At the bottom of the planula, a polyp is formed that can reproduce asexually - by budding. It is characteristic that daughter organisms form in the upper part of the polyp, as if layering on top of each other. Ultimately, such a polyp resembles a stack of plates stacked on top of each other, the uppermost individuals gradually separate from the polyp and swim away. Free-swimming individuals of hydroid jellyfish are actually young jellyfish that gradually grow and mature; in scyphoid jellyfish, such an individual is called an ether, since it differs sharply from an adult jellyfish. After some time, the ether turns into an adult. But in the jellyfish pelagia and several species of trachilids, the polyp stage is completely absent; in them, mobile individuals are formed directly from the planula. Bougainvillea and Campanularia jellyfish have gone even further, in which polyps are formed directly in the sex glands of adults, it turns out that the jellyfish gives rise to tiny jellyfish without any intermediate stages. Thus, in the life of jellyfish, there is a complex alternation of generations and methods of reproduction, and several individuals are formed from each egg at once. The reproduction rate of jellyfish is very high and they quickly restore their numbers even after natural disasters. The life expectancy of jellyfish is short - most species live for several months, the largest species of jellyfish can live 2-3 years.
The dome of this jellyfish is decorated with stripes.
A tiny fish hides under the dome of a jellyfish.
The green turtle eats the jellyfish.
Jellyfish have been known to people since ancient times, however, due to their negligible economic value, they long time did not attract attention. The word medusa itself comes from the name of the ancient Greek goddess Gorgon Medusa, whose hair, according to legend, was a bunch of snakes. Apparently, the moving tentacles of jellyfish and their poisonousness reminded the Greeks of this evil goddess. However, little attention was paid to jellyfish. The exception was the countries of the Far East, whose inhabitants loved exotic food. For example, the Chinese eat eared jellyfish and edible ropil. One side the nutritional value jellyfish is negligible, since their body mainly consists of water, on the other hand, the abundance and availability of jellyfish suggested that at least some benefit be derived from them. To do this, the Chinese first cut poisonous tentacles from jellyfish, and then salt them with alum and dry them. Dried jellyfish resemble strong jelly in consistency, they are cut into strips and used in salads, as well as boiled, fried with pepper, cinnamon and nutmeg. Despite such tricks, jellyfish are practically tasteless, so their use in cooking is limited. national cuisines China and Japan.
Eared jellyfish is one of the edible species.
In nature, jellyfish bring some benefit, cleaning sea waters from small organic debris. Sometimes jellyfish breed so strongly that they clog water sumps in desalination plants with their mass, pollute the beaches. However, jellyfish should not be blamed for this sabotage, since the culprits of such outbreaks are the people themselves. The point is that emissions organic matter and the biological debris that fills the oceans is food for jellyfish and provokes their reproduction. This process is facilitated by the lack fresh water, since with an increase in the salinity of the sea, jellyfish breed better. Since jellyfish breed well, there are no endangered species among them.
Seasonal invasion of jellyfish in the Black Sea is a common occurrence.
Under natural conditions, jellyfish do not pose any particular benefit or harm to humans. However, the venom of some species can be dangerous. Poisonous jellyfish can be conditionally divided into two groups: in some species, the poison has an irritating effect and can cause allergies, in others, the poison acts on the nervous system and can lead to serious disruption of the heart, muscles, and even death. For example, the "sea wasp" jellyfish that lives in the waters of Australia has caused the death of several dozen people. Touching this jellyfish causes severe burns, after a few minutes convulsions begin and many people die before they can swim to shore. However, the sea wasp has an even more terrible competitor - the Irukandji jellyfish, which lives in pacific ocean. The danger of this jellyfish is that it is very small (12 cm in diameter) and stings almost painlessly, so swimmers often ignore its bite. At the same time, the poison of this crumb acts very quickly. Despite this, the danger of jellyfish in general is greatly exaggerated. In order to protect yourself from unpleasant consequences, it is enough to know a few rules:
- do not touch unknown species of jellyfish - this applies not only to living jellyfish swimming in the sea, but also to dead ones thrown ashore, because stinging cells can act for some time after the death of a jellyfish;
- in case of burns, get out of the water immediately;
- rinse the bite site with plenty of water until the burning sensation stops;
- in case the discomfort persists, wash the bite site with a solution of vinegar and immediately call ambulance(usually in such cases adrenaline injections are given).
Burns on a swimmer's hand left by a jellyfish.
Usually, a jellyfish sting victim recovers in 4-5 days, but one thing should be taken into account: jellyfish venom can act as an allergen, so if you meet the same type of jellyfish again, the second burn will be much more dangerous than the first. In this case, the reaction of the body to the poison develops faster and more powerfully, and the threat to life increases many times over. Nevertheless, the mortality from encounters with jellyfish is negligible and inferior to accidents with other animal species.
Jellyfish at the Monterey Public Aquarium.
Despite some hostility of jellyfish to humans, it has recently become fashionable to keep them in an aquarium. The smooth continuous movements of these fantastic creatures bring peace and soothe the nerves. However, the maintenance of jellyfish in an aquarium is associated with some difficulties: jellyfish are very sensitive to water pollution, do not tolerate desalination, and require a more or less pronounced flow of water. Most often they are kept in large public aquariums, where it is relatively easy to ensure the purity of the water and create a current. However, at home, jellyfish can also be kept. For home keeping, the moon jellyfish and the cassiopeia jellyfish are used, which will reach 20 and 30 cm in diameter, respectively. Only a special marine aquarium is suitable for keeping both species, always with a powerful water purification system, including mechanical filtration. In the aquarium, you need to create a current, but at the same time, make sure that the jellyfish is not sucked into the filter by the current. Jellyfish require special lighting, so metal halide lamps will have to be installed in the aquarium. Please note that the water temperature for the moon jellyfish should not exceed 12-18 ° C, Cassiopeia may well live at room temperature. You need to feed jellyfish with live food - brine shrimp, it is easy to purchase in specialized stores, from amateur aquarists. Both species are not dangerous, but can still cause painful burns, so be careful when caring for jellyfish. Do not forget that jellyfish will not tolerate proximity to fish; only immobile animals or bottom organisms can be settled in their aquarium.
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 Gorgon. The hair of this goddess represented a moving bunch 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 oceans. Only one freshwater species is known marine life. Each species occupies an area limited to one body of water and can never be found in another sea or ocean. Jellyfish are cold-water and thermophilic; deep-sea and those that keep near the surface.
However, at the surface, such species swim only at night, and during the day they dive to 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. Varieties of jellyfish
More than 200 species of jellyfish are known in nature. Despite the primitive structure, they are very diverse. Their sizes vary from 1 to 200 cm in diameter. The largest jellyfish is the lion's mane (cyanoea). Some of its specimens can be up to 1 ton in weight and with a tentacle length of 35 m.
Jellyfish are shaped like a disk, an umbrella or a dome. Most jellyfish have a transparent body, sometimes with bluish, milky, yellowish hues. But not all species are so plain, there are truly beautiful ones among them, bright colors: red, pink, yellow, purple, speckled and striped. Green jellyfish do not exist in nature.
Species such as Aequorea, Pelagia Nightlight, Ratkeya can glow in the dark, causing a phenomenon called bioluminescence. Deep-sea jellyfish emit red light, floating near the surface - blue. There is a special kind of jellyfish (stauromedusa) 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 has no skeleton, it is 98% water. Cast ashore, the jellyfish is not able to move and instantly dries up. Its consistency resembles jelly, which is why the British called it "jelly fish".
The tissues of the body have only two layers, which are interconnected by an adhesive substance and perform different functions. The cells of the outer layer (ectoderm) are “responsible” for movement, reproduction, and are analogues of the skin and nerve endings. The cells of the inner layer (endodermis) 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 for different types of jellyfish. The umbrella is surrounded by trapping tentacles, which, depending on the species, can be either thick and short, or thin, filiform, long.
What do jellyfish eat
Jellyfish are predators, they consume only animal food (crustaceans, fry, small fish, caviar). They are blind and have no sense organs. Jellyfish hunt in a passive way, catching with their tentacles the edible that the current brings. Trapping tentacles kill prey. This is done in different ways.
This is the largest jellyfish in the world - cyanide, 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, others have sticky threads in which it gets tangled. The tentacles push the paralyzed victim towards the mouth, through which the undigested remains are then excreted. It is interesting that jellyfish living at depth attract prey with their bright glow.
How jellyfish breed
Jellyfish have vegetative (asexual) and sexual reproduction. Outwardly, males are no different from females. Spermatozoa and eggs are released into the water through the mouth, 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 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 lack the polyp stage. Juveniles immediately form 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.
The vitality of jellyfish
Although jellyfish do not live long - from several months to 2-3 years, their numbers are very quickly restored even after various cataclysms. 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.
It is interesting that if such an operation is performed at different ages of the jellyfish, then an individual of the corresponding stage of development grows out of the tissues. If you divide the larva, then two larvae will grow, and from the adult parts - jellyfish of the appropriate age.
Medusa 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, the poison of others acts on the nervous system and can cause serious disorders in the muscles and heart, and in some cases death.
In order not to put yourself in danger, you need not touch the jellyfish, both living and dead. In case of a burn, wash the injured area with water, and preferably with a solution of vinegar. If the pain does not subside and there are complications, you should immediately call a doctor.
Jellyfish are amazing and very extraordinary creatures, causing a whole range of emotions from delight and admiration to disgust and fear. Jellyfish can be found in every sea, in every ocean, on the surface of the water or many kilometers deep.
Jellyfish are the oldest animals on the planet, their history goes back at least 650 million years. In nature, there are an incredible number various types, but even at the present time, the emergence of new, previously unfamiliar to mankind, is being recorded.
(MODULE=240&style=margin:20px;float:left;)
Jellyfish washed up on the sand of Belmedie Beach, Scotland
In fact, jellyfish or medusa generation are one of the phases of the life cycle of the cnidarian Medusozoa, which are usually divided into three types: hydroid, scyphoid and box jellyfish. Jellyfish reproduce sexually. There are males that produce sperm and females that produce eggs. As a result of their merger, the so-called planula is formed - the larva of the jellyfish. Planula settles to the bottom, where over time it turns into a polyp (asexual generation of jellyfish). Reaching full maturity, the polyp begins to bud off the young generation of jellyfish, often not at all like adults. In scyphoid jellyfish, the newly separated specimen is called the ether.
The body of jellyfish is a jelly-like dome, which, through contractions, allows them to move in the water column. Tentacles, equipped with stinging cells (cnidocytes) with burning poison, are designed for hunting and capturing prey.
Jellyfish at Shark Bay Manaday Reef Aquarium in Las Vegas, Nevada
The term "jellyfish" was first used by Carl Linnaeus in 1752 as an allusion to the animals' resemblance to the head of the Gorgon Medusa. Popularized around 1796, the name has also been applied to other medusoid species, such as ctenophores.
Jellyfish on display at Long Beach in California
Did you know? 10 interesting facts about jellyfish:
The largest jellyfish in the world can reach 2.5 meters in diameter and have tentacles over 40 meters long.
Jellyfish are able to reproduce both sexually and by budding and fission.
(MODULE=241&style=margin:20px;float:left;)
Jellyfish "Australian wasp" is the most dangerous poisonous animal in the world's oceans. The venom of a sea wasp is enough to kill 60 people.
Even after the death of a jellyfish, its tentacles are able to sting for more than two weeks.
Jellyfish do not stop growing throughout their lives.
Large clusters of jellyfish are called "swarm" or "bloom".
Some types of jellyfish are eaten in East Asia, considering them a "delicacy".
Jellyfish don't have a brain respiratory system, circulatory, nervous and excretory systems.
The rainy season significantly reduces the number of jellyfish that live in salt water.
Some female jellyfish can produce up to 45,000 larvae (planula) per day.
The most incredible and bizarre forms
Aequorea Victoria or jellyfish "crystal"
Elegant dance of jellyfish
Aurelia - "butterflies"
Eared aurelia (lat. Aurelia aurita) - a species of scyphoid from the order discomedusa (Semaeostomeae)
glowing ctenophore
A pink jellyfish from the Scyphozoan family was discovered more recently, just over 10 years ago, in the waters Gulf of Mexico and the Caribbean. Some individuals of this species reach 70 cm in diameter. Pink jellyfish can inflict severe and painful burns, especially if the bather inadvertently finds himself among a large concentration of these creatures.
Antarctic Diplulmaris
The Antarctic Diplulmaris is a species of jellyfish in the Ulmaridae family. This jellyfish was discovered recently in Antarctica, in the waters of the continental shelf. The Antarctic Diplulmaris is only 4 cm in diameter.
Aurelia eared (lat. Aurelia aurita) or moon jellyfish
Pacific sea nettle (Chrysaora fuscescens)
Flower Hat Jellyfish (Olindias formosa)
Jellyfish "flower hat" (lat. Olindias Formosa) - one of the types of hydroid jellyfish from the order Limnomedusae. Basically, these cute creatures live off the southern coast of Japan. A characteristic feature is the motionless hovering near the bottom in shallow water. The diameter of the "flower cap" usually does not exceed 7.5 cm. The tentacles of the jellyfish are located not only along the edge of the dome, but also over its entire surface, which is not at all typical for other species.
A flower cap burn is not fatal, but it is quite painful and can lead to severe allergic reactions.
Scyphoid jellyfish rhizostoma (Rhizostoma pulmo) or cornerot
Incredible bioluminescent jellyfish
Jellyfish - an inhabitant of the coast of the Federated States of Micronesia
Purple-striped jellyfish (Chrysaora colorata)
Purple-striped jellyfish (lat. Chrysaora Colorata) from the class Scyphozoa is found only off the coast of California. This rather large jellyfish reaches 70 cm in diameter, the length of the tentacles is about 5 meters. A characteristic feature is the striped pattern on the dome. In adults, it has a bright purple color, in young ones it is pink. Usually purple-striped jellyfish are kept singly or in small groups, unlike most jellyfish of other species, which often form huge colonies. Chrysaora colorata burn is quite painful, but not fatal to humans.
Pelagia Noctiluca, known in Europe under the name "purple sting"
Giant Nomura jellyfish (Nemopilema nomurai)
Giant Nomura jellyfish (lat. Nemopilema nomurai) is a species of scyphoid jellyfish from the Cornerot order. This species predominantly inhabits the East China and Yellow Seas. The size of this species is really impressive! They can reach 2 meters in diameter and weigh about 200 kg.
The name of the species was given in honor of Mr. Kan'ichi Nomura, CEO fisheries in Fukui Prefecture. In early 1921, Mr. Nomura first collected and studied a hitherto unknown species of jellyfish.
Currently, the number of Nomura jellyfish in the world is growing. Possible reasons population growth, scientists consider climate change, overexploitation of water resources and pollution environment.
In 2009, a 10-ton fishing trawler capsized in Tokyo Bay with three crew members trying to pull nets overflowing with dozens of Nomura jellyfish.
Large red jellyfish (Tiburonia granrojo)
Jellyfish appeared 650 million years ago, when the world's oceans were a primitive mixture of microorganisms. They are being watched, they are trying to explore, but they are still a mystery to scientists, as some jellyfish live at a depth of up to 10 thousand meters. The medusa owes its name to the ancient Greek Medusa Gorgon, whose hair, according to legend, was a ball of snakes. Now jellyfish are creatures polished by millions of years of evolution, perfect rulers of the seas, predators armed with a poison that includes so many toxins that it is impossible to create an antidote.
It is impossible not to admire the grace of a jellyfish, watching its smooth gliding in the water column. Similar to alien ballerinas, jellyfish slowly cut through the waves, striking with the variety of their appearance and size. They invariably arouse interest and even horror, not without reason the fear of jellyfish has a separate name - meduphobia. The skin, nerves, muscles of jellyfish are transparent, they have no brain and eyes. They consist of about 95% water, 3-4% salt and 1-2% protein. And although in the national Chinese and Japanese cuisine jellyfish are used to cook soups, salads, tofu and even special cookies, in most cases it is the jellyfish that poses a threat to humans, and not vice versa. More and more more places in the world is suffering from an invasion of jellyfish due to a violation of the biobalance, and it is impossible to predict where the danger lies. If you have strashno.com meduphobia, then our review is likely to be unpleasant for you.
1) Sea wasp (Chironex fleckeri)
The sea wasp rightfully occupies the first place, as it is the most poisonous and dangerous jellyfish in the oceans, and perhaps the most dangerous animal in the whole world. The sea wasp is a species of sea cnidar that belongs to the class of box jellyfish. She lives on the coast northern australia and in Indonesia, its tentacles are completely covered with stinging cells (nematocytes), which contain a very strong poison. The stings of this box jellyfish cause excruciating pain and are powerful enough to kill 60 people in three minutes. It is believed that over the past 100 years, up to 100 deaths have been caused by sea wasp burns, and it is not for nothing that the natives speak of it with reverent horror.
Usually, the sea wasp strikes its prey in several places at once in order to paralyze it and cause a widespread infestation. strashno.com Experienced people know that it is dangerous to swim in some waters on a calm and cloudless day - the tide brings sea wasps to the shore. At the four corners of the dome, 24 organs are evenly distributed, similar to the eyes, of which every four eyes in the corner perceive the image, and the other two perceive the light. Jellyfish have four tufts of 15 tentacles extending from each four corners domes. When a jellyfish swims, the tentacles contract, reaching a length of 15 cm and a thickness of 5 mm. During the hunt, the tentacles become thinner and stretch up to 3 meters in length.
The venom of a sea wasp can kill an adult human in less than 5 minutes. There is an antidote for her poison, but it is necessary to have time to introduce it at these moments, which is often impossible. Bathers who are stung often have a heart attack and drown before they reach the boat or the shore. The most dangerous jellyfish is considered much more terrible than the cannibal shark: its small size and pale, translucent color make the animal almost invisible in the water, and it is quite difficult to avoid meeting it. The dome of the sea wasp reaches the size of an ordinary basketball. Sea wasps feed on shrimp and small fish. And the inhabitants of the seas themselves serve as food for sea turtles. These are the only creatures on the planet that are not sensitive to this poison.
2) Irukandji jellyfish (Carukia barnesi)
It is a group of Pacific jellyfish of extraordinary toxicity. Irukandji can be found in Australian waters and the seas of the tropics of Oceania. But according to recent studies, global warming, including ocean waters, leads to the gradual spread of irukandji in the waters of the oceans. An adult Irukandji, which looks like a small transparent whitish bell, is approximately 12 × 25 mm in size. She also has 4 long, thin, almost transparent tentacles ranging in length from a few millimeters to strashno.com 1 meter, covered with stinging cells.
The poison, when acting on a person, causes a whole chain of paralytic effects, such as: strong headache, back pain, muscle pain, abdominal and pelvic pain, nausea and vomiting, sweating, restlessness, hypertension, tachycardia and pulmonary edema. There is Irukandji syndrome, which can last from several hours to several days, in some cases it can lead to death, accompanied by monstrous pain throughout the body, lasting about a day. A dangerous factor is the fact that this box jellyfish does not release poison with the whole cell (like a sea wasp), but shoots it from the tip of the tentacle, which is why the poison has a delayed effect, and a light bite is not taken seriously by bathers.
3) Portuguese boat or physalia (Physalia physalis)
These animals belong to the subclass of siphonophores in the class of hydroid jellyfish, i.e., by definition, they are not jellyfish, strashno.com, but colonies. Physalia is very beautiful - it can be seen from afar on the water, because it is a "sailboat" and floats on the surface of the sea, driven by winds and currents. The sail (swimming bladder) of the physalia is painted in beautiful tones from blue to violet and purple. The diameter of the umbrella-dome of the physalia is small, no more than 25 cm, but in the underwater part it has long (up to several meters) tentacles, equipped with numerous stinging cells. Portuguese boats feed mainly on fish larvae, as well as small fish and small squids. Themselves Portuguese boats eat only sea turtles.
Upon contact with the tentacles of the physalia, the swimmer receives a severe burn, which causes excruciating pain. Soon other symptoms of poisoning appear - damage to the nervous and circulatory systems, respiratory function, fever and general malaise. A person struck by the poison of physalia can hardly keep afloat and often drowns. Initially, Portuguese strashno.com boats could only be found in the waters of the Gulf Stream, as well as in the tropics of the Indian and Pacific Oceans. But since 1989, whole fleets of these jellyfish are not uncommon in the Mediterranean Sea. Scientists believe that the main reasons for their resettlement were global warming and the disappearance of food due to the large volumes of fish caught. When physalia accumulate off the coast of England, France, Spain or Florida, the media alert the coastal population of the danger. Encounters with physalia are easier to avoid than with the same "sea wasp" - it is clearly visible from afar due to the bright color of the dome. However, cases of “burning” by goads of these animals do occur.
4) Jellyfish-cross or jellyfish-cross (Gonionemus vertens)
Belongs to the class of hydroid jellyfish and lives in coastal waters North Pacific from China to California. A small population of these jellyfish has been recorded in the western Atlantic. The diameter of the bell can reach strashno.com 40 mm, usually no more than 20 mm. The body is transparent with a brown-red cross inside - a pattern formed by colored internal organs(radial channels digestive system). Numerous tentacles of the cross (up to 80 pieces) are located along the edge of the umbrella and can be strongly extended and contracted. The clinging jellyfish sometimes literally terrorizes Primorye. Every year, hundreds of people turn to hospitals with complaints of being burned by this jellyfish. The residents of Primorye especially remember the year 1970, when 1360 people suffered from touching the crosses in just one day, of which 116 were hospitalized.
The spider venom is painful, but not fatal. However, if the victim receives repeated burns by this jellyfish, the consequences can be much more serious, up to the death of a person. Gonionemus vertens is called a clinging jellyfish for special suction cups on its tentacles, with the help of which the cross is attached to algae and various underwater objects. When a bather touches one strashno.com of the jellyfish's tentacles, it rushes with its whole body in this direction, trying to attach itself with the help of suction cups. The bather gets a noticeable burn, the contact area turns red and even blistered. In such cases, it is urgent to get out of the water, because after a while (10-30 minutes) back pain, numbness of the limbs, difficulty breathing, nausea, and thirst begin to appear. The poison of the cross also acts on the nervous system, causing excessive excitement or severe depression. The action of the poison lasts 3-4 days, but can be felt much longer.
5) Hairy cyanide, giant cyanide or arctic cyanide (Cyanea capillata, Cyanea arctica)
A species of scyphoid from the detachment of disc jellyfish. Arctic cyanoea is the most big jellyfish World Ocean. The tentacles of the most impressive specimens can stretch up to 20 m. Usually, cyanideas do not grow more than 50-60 cm. in black and Seas of Azov not detected. The cyanide sting is incapable of causing death in humans, although the rash can be painful and the toxins in the venom can cause allergies. To date, a jellyfish of this species with a body diameter of 2.3 m and a tentacle length of 37 m has been documented. It was washed ashore in Massachusetts Bay (USA) in 1870. Thus, this sample was larger blue whale, which is considered to be the largest animal on the planet. And who knows, maybe this is far from the limit?
These jellyfish are inhabitants of the seas and oceans and rarely approach the shores, swimming at the behest of currents and the lazy movement of tentacles at depths of no more than 20 meters. Most of the time, cyanideas hover in the near-surface layer of water, periodically shortening the dome and flapping their edge blades. At the same time, the tentacles of the jellyfish are straightened and extended strashno.com to their full length, forming a dense trapping net under the dome. Long, numerous tentacles densely covered with stinging cells. When they are fired, a strong poison penetrates the victim's body, killing small animals and causing significant damage to larger ones. Cyanide prey - various planktonic organisms, including other jellyfish.
The jellyfish of this species made such a strong impression on the British writer Arthur Conan Doyle that he captured cyanide in his detective story "The Lion's Mane".
6) Nomura Bell (Nemopilema nomurai)
A species of scyphoid from the order Cornerotes (Rhizostomeae), capable of reaching over 2 m in diameter and weighing more than 200 kg. Nomura jellyfish are often found in Far Eastern seas, off the coast of China and Korea, are sometimes found in the coastal waters of Japan. These giant jellyfish cause great harm local fishing industry strashno.com. They get into fishing nets, confuse them, and when the nets are released, they injure fishermen with toxic goads. Cases of death of people affected by the venom of nomura goads have also been registered, but such tragic outcomes are extremely rare and are mainly caused by an allergic reaction to the venom of this jellyfish.
This graceful species of jellyfish, not yet very well studied by science, can be found in Monterrey Bay, California. This jellyfish has quite big sizes- The diameter of her umbrella reaches 70 cm, and she can cause serious burns to a person. Stripes and color saturation appear in jellyfish with age. In the course of warm currents, the jellyfish can also migrate to the shores of Southern California. This was especially noticeable in 2012, when 130 people received jellyfish burns.
8) Formosa jellyfish or flower hat jellyfish (Olindias formosa)
A species of hydroid from the strashno.com order Limnomedusa, living off the southern coast of Japan. Jellyfish of this species are characterized by hovering in immobility near the bottom in shallow water areas. In the summer of 1979, during an outbreak in Nagasaki Prefecture, several dozen bathers were burned. The diameter of the umbrella of adult jellyfish is about 7.5 cm with half the height. The tentacles of the jellyfish are located not only along the edge of the dome, but also over its entire surface, which is not at all typical for other species. A flower cap burn is not fatal, but it is quite painful and can lead to severe allergic reactions.
9) Pelagia jellyfish, night light or purple sting (Pelagia noctiluca)
A species of disc jellyfish, widespread in all warm and temperate waters of the World Ocean, especially in the Mediterranean and Red Seas and the Atlantic Ocean. Often found in the Pacific Ocean near the Hawaiian Islands, Southern California and Mexico. This is a medium-sized jellyfish, rarely exceeding strashno.com in the umbrella diameter of 12 cm, the color of the dome varies from purple to brownish red. The edge of the bell decorated with frills is equipped with eight thin stinging cells, tentacles and four oral lobes extending from the mouth opening. The name of this jellyfish is translated as "evening light" because of the colorful color of the dome and the ability to emit light when touching any objects underwater. Pelagia feeds mainly on benthos, but can also hunt small animals - fry, crustaceans. Pelagia poison is dangerous for humans, it can cause burns and even shock.
10) Pacific sea nettle or Chrysaora jellyfish (Chrysaora fuscescens)
It lives in the Pacific Ocean from Canada to Mexico, feeds on small animals and other jellyfish. The diameter of its dome can reach more than 1 meter, but more often no more than 50 cm. The sea nettle has a golden brown color and a reddish hue of the body. Throughout the dome, there are marginal strashno.com tentacles, there are 24 of them in total, they are collected in eight groups of three. These tentacles are capable of reaching a length of three to four meters. If the tentacles of this jellyfish come off the body, they swim in the ocean and at the same time can sting for another two weeks. After the burn sea nettle a thin red scar appears, as after a lash. Although victims experience severe pain and burning, turning into medical institution usually not required. This is a popular jellyfish for aquariums and oceanariums, as its bright coloring, elegance and simplicity of content attract attention.
If you are stung by a jellyfish, remember that it is necessary to clean the burn site from the remnants of stinging cells and poison as soon as possible. To do this, wash the burn area with salt water and carefully scrape the stinging cells from the skin with a safety razor, the blunt side of a knife, or any convenient piece of plastic. Then take an anesthetic and antihistamine inside strashno.com and consult a doctor.
What not to do:
- rub the burn area;
- Rinse with soda, alcohol, fresh water, lemon juice, because. this, on the contrary, activates the stinging cells of the jellyfish.
Do not forget that jellyfish washed ashore for 48 hours retain the ability to sting. Avoid touching them and do not let children play with them.
Jellyfish can rightly be called one of the most mysterious inhabitants of the deep sea, causing interest and a certain fear. Who are they, where did they come from, what varieties are there in the world, what is their life cycle, are they so dangerous, as popular rumor says - I want to know about all this for sure.
Jellyfish appeared more than 650 million years ago, they can be called one of the oldest organisms on Earth.
About 95% of the body of a jellyfish is water, which is also their habitat. Most jellyfish live in salt water, although there are species that prefer fresh water. Jellyfish - a phase of the life cycle of representatives of the genus Medusozoa, "sea jelly" alternates with an immobile asexual phase of immobile polyps, from which they are formed by budding after maturation.
The name was introduced in the 18th century by Carl Linnaeus, he saw in these strange organisms a certain resemblance to the mythical Gorgon Medusa, due to the presence of tentacles that flutter like hair. With their help, the jellyfish catches small organisms that serve as food for it. The tentacles may look like long or short, spiky threads, but they are all equipped with stinging cells that stun prey and facilitate hunting.
Life cycle of scyphoid: 1-11 - asexual generation (polyp); 11-14 - sexual generation (jellyfish).
Glowing jellyfish
The one who saw how it glows on a dark night sea water, he is unlikely to be able to forget this spectacle: myriads of lights illuminate sea depth shimmer like diamonds. The reason for this amazing phenomenon is the smallest planktonic organisms, including jellyfish. One of the most beautiful is considered a phosphorus jellyfish. It is not found very often, living in the near-bottom zone off the coast of Japan, Brazil, and Argentina.
The diameter of the umbrella of a luminous jellyfish can reach 15 centimeters. Living in the dark depths, jellyfish are forced to adapt to the conditions, provide food for themselves, so as not to disappear altogether as a species. An interesting fact is that the bodies of jellyfish do not have muscle fibers and cannot resist water flows.
Since the slow-moving jellyfish, floating by the will of the current, cannot keep up with moving crustaceans, small fish or other planktonic inhabitants, you have to go to the trick and force them to swim themselves, right to the predatory open mouth opening. And the best bait in the darkness of the bottom space is light.
The body of a luminous jellyfish contains a pigment - luciferin, which is oxidized under the influence of a special enzyme - luciferase. Bright light attracts victims like moths to a candle flame.
Some species glowing jellyfish, such as Ratkeya, Equorea, Pelagia live near the surface of the water, and, gathering in large quantities they literally make the sea burn. Amazing Ability to emit light interested scientists. Phosphors have been successfully isolated from the jellyfish genome and introduced into the genomes of other animals. The results were quite unusual: for example, mice whose genotype was changed in this way began to grow green hairs.
Poison jellyfish - Sea Wasp
Today, more than three thousand jellyfish are known, and many of them are far from harmless to humans. Stinging cells, “charged” with poison, have all types of jellyfish. They help to paralyze the victim and deal with it without any problems. Without exaggeration, for divers, swimmers, fishermen is a jellyfish, which is called the Sea Wasp. The main habitat of such jellyfish is warm tropical waters, especially a lot of them near the coast of Australia and Oceania.
Transparent bodies of pale blue color are invisible in warm water quiet sandy coves. The small size, namely, up to forty centimeters in diameter, also does not attract special attention. Meanwhile, the poison of one individual is enough to send about fifty people to heaven. Unlike their phosphorescent counterparts, sea wasps can change direction, easily finding careless bathers. The poison that enters the body of the victim causes paralysis of smooth muscles, including the respiratory tract. Being in shallow water, a person has a small chance to escape, but even if medical assistance was provided in a timely manner and the person did not die from suffocation, deep ulcers form at the “bites”, causing severe pain and not healing for many days.
Dangerous little ones - Irukandji jellyfish
Similar action to human body, with the only difference that the degree of damage is not so deep, the tiny Irukandji jellyfish, described by the Australian Jack Barnes in 1964, have. He, as a true scientist, standing up for science, experienced the effect of poison not only on himself, but also on his own son. Symptoms of poisoning - severe headache and muscle pain, convulsions, nausea, drowsiness, loss of consciousness - are not fatal in themselves, but the main risk is a sharp increase blood pressure from a person who personally met Irukandji. If the victim has problems with the cardiovascular system, then the probability lethal outcome pretty big. The size of this baby is about 4 centimeters in diameter, but thin spindle-shaped tentacles reach 30-35 centimeters in length.
Bright beauty - jellyfish Physalia
Another very dangerous inhabitant for humans tropical waters is Physalia - Sea boat. Her umbrella is painted in bright colors: blue, purple, magenta and floats on the surface of the water, so it is noticeable from afar. Entire colonies of attractive sea "flowers" attract gullible tourists, beckoning them to pick them up as soon as possible. This is where the main danger lurks: long, up to several meters, tentacles are hidden under water, equipped with a huge number of stinging cells. The poison acts very quickly, causing severe burns, paralysis and disruption of the cardiovascular, respiratory and central nervous systems. If the meeting took place on great depth or simply far from the coast, then its outcome may be the saddest.
Giant Jellyfish Nomura - Lion's Mane
The real giant is the Nomura Bell, also called lion's mane for some resemblance with the king of beasts. The diameter of the dome can reach two meters, and the weight of such a "baby" reaches two hundred kilos. It lives in the Far East, in the coastal waters of Japan, off the coast of Korea and China.
A huge hairy ball, falling into the fishing nets, damages them, causing damage to the fishermen and shooting themselves when they try to free themselves. Although their poison is not fatal to humans, meetings with the Lion's Mane rarely take place in a friendly atmosphere.
One of the largest jellyfish is considered Cyanea. Dwelling in cold waters, she reaches largest sizes. The most gigantic specimen was discovered and described by scientists at the end of the 19th century in North America: its dome was 230 centimeters in diameter, and the length of the tentacles was 36.5 meters. There are a lot of tentacles, they are collected in eight groups, each of which has from 60 to 150 pieces. It is characteristic that the dome of the jellyfish is also divided into eight segments, representing a kind of octagonal star. Fortunately, it does not live in the Azov and Black Seas, so you can not be afraid of them when going to the sea to relax.
Depending on the size, the color also changes: large specimens are painted in bright purple or purple, smaller ones are orange, pink or beige. Cyanei live in surface waters, rarely descending into the depths. The poison is not dangerous to humans, causing only an unpleasant burning sensation and blisters on the skin.
The use of jellyfish in cooking
The number of jellyfish living in the seas and oceans globe truly huge, and none of the species is threatened with extinction. Their use is limited by the possibilities of extraction, but people have long been using beneficial features jellyfish for medicinal purposes and enjoy their taste in cooking. In Japan, Korea, China, Indonesia, Malaysia and other countries, jellyfish have long been eaten, calling them "crystal meat". Its benefits are due to the high content of protein, albumin, vitamins and amino acids, trace elements. And with proper preparation, it has a very refined taste.
Jellyfish "meat" is added to salads and desserts, to sushi and rolls, soups and main dishes. In a world where population growth steadily threatens the onset of famine, especially in underdeveloped countries, jellyfish protein can become good help in resolving this issue.
Jellyfish in medicine
The use of jellyfish for the manufacture of medicines is typical, to a greater extent, in those countries where their use in food has long ceased to be a subject of surprise. For the most part, these are countries located in the seaside, where jellyfish are directly harvested.
In medicine, preparations containing processed bodies of jellyfish are used to treat infertility, obesity, baldness and gray hair. The poison extracted from stinging cells helps to cope with diseases of the upper respiratory tract and normalize blood pressure.
Modern scientists are struggling to find medicinal product, capable of defeating cancerous tumors, not excluding the possibility that jellyfish will also help in this difficult struggle.