About 700 million years ago, at the end of the Proterozoic, in the ocean, the first primitive invertebrate organisms: worms and jellyfish. Ever since jellyfish - the most common predators in our land.

Giants and dwarfs

At the touch of a jellyfish flabby, it has neither the internal nor the external skeleton, and at first glance it is not clear what, as they say, its "soul" is held. But in fact the body jellyfish dense and well retains its shape. This is because all gelatinous weight, animal permeated fairly strong fibers. In addition Medusa able to pump up water, making her body becomes elastic. This way of keeping fit body is called hydrostatic skeleton. Water allows Medusa and move. Working as a pump, animal draws it in ourselves, and then, sharply Contracting, pushes out. It's like a jet engine - water is ejected in one direction, and the animal itself is moving in the opposite.

For the overall similarity between the structure of the dome and the tentacles) jellyfish differ quite a variety of form and color and about the size and say nothing! For example, the Medusa coloboma, living at depths of 500 to 1500 m, diameter of the dome of only five centimeters. To compensate for the small size of the nature gave calabona large number of tentacles (32 units), which, in turn, have a very interesting feature, characteristic terrestrial lizards, - in case of emergency they can be easily discharged with his mistress, and then grow again.

The complete opposite colabo-dumb - Arctic giant jellyfish cyanea living in the North-West Atlantic. One of these jellyfish found on the shore of Massachusetts Bay, had the diameter of the dome is about 2.5 metres, and its tentacles stretched 36.5 meters.

But regardless of the size of these marine animals are United by one thing: the need for constant power. It can be said that the purpose of all life jellyfish. The main object of hunting fish, and consume it jellyfish in very large numbers.

A wasp sting

As already mentioned, some poisonous jellyfish, but not dangerous to humans. However, among jellyfish are the real killers, meeting with which can result in death for any living creature. The most "burning" example-sea wasp, or as it is also called, ocean stinger.

Thousands of tourists annually come to relax on the gorgeous beaches of Northern Australia. And here, among the pristine beauty of nature, they can wait for death. At first glance, sea wasp is not so terrible - conventional domed Medusa no bigger than a basketball and a tuft of hair tentacles of up to eight meters. But is this animal is considered one of the most dangerous on earth. The poison that contains ocean stinger, similar to Cobra venom and works well. After contact with the sea wasp man instantly interrupted breathing, and 2-3 minutes is paralysis of the heart. Stock poison the stinger will last for fifty people.

The sea wasp has one more peculiarity: this jellyfish has a vision. She looked at the surrounding space through four groups of pupils. Another thing that is absolutely not clear where to get the visual signals because the brain in jellyfish is missing. It is also noticed that Medusa not attacking. She waits for shrimp, fish, or people will stumble upon one of the tentacles, where in an instant as the bullet flies sting of poison.

Consequences bite marine Stingers difficult to cure. If snakes and spiders bite his sacrifice once and in only one place, the sea wasp stings his victim in several places. However, recently the Australian scientists were able to synthesize antibodies, which proved to be very effective antidote. After the injection, the victim almost instantly recovered breath and acute pain weakened after a few minutes.

Scientists have found that the marine wasp is only one enemy - species of sea turtles that feed on these jellyfish and are not afraid of their deadly poison. As it turns out - is still unknown. And while the authorities have advised people to dress in light diving suits or, at worst, in lycra, which produce women's tights.

The syndrome irukandji

In addition to marine Stingers Australian coast have chosen another jellyfish-killer - carukia barnesi. However, unlike stinger, to notice barnesi in the water is almost impossible - the diameter of the dome is only 12 mm. However, due to this animal Australia met with the so-called syndrome of irukandji, who was killed in 2002, few tourists. The syndrome has received its name from the tribe of natives of irukandji living in palm Cove, on the northeast coast of Australia, where a meeting with Medusa-killer-usual case.

It all starts with a sting, like a gnat. Then within an hour, the victim suffers from severe lower back pain, backache throughout the body, convulsions, nausea, vomiting, cough; abundantly allocated sweat. Consequences bite barnesi extremely serious: from paralysis to bleeding in the brain or the heart stops.

Boom

For yet unknown reasons in recent years, the tribe of jellyfish is undergoing a demographic explosion. In March of this year a thousand slimy animals flooded coast of Australia. Locals and tourists literally in panic, and scientists can not explain the reason of such a powerful invasion.

- I have never seen anything like it, " says the representative of the Oceanographic Institute Trevor long. - Tens of thousands of them, and is becoming more and more with each tide. All water is teeming with them. This is a very impressive and strange phenomenon.

In may this year in Sevastopol bathing season is over, failing to properly begin. The reason is that the Black sea flooded jellyfish. Worth about one meter from the Bank, but are not floating in the water, and solid "carpet" of the more unpleasant to touch organics - the living and the dead jellyfish. Ukrainian scientists, as their Australian colleagues, can't find the reasons for the invasion. Authorities suggest that get into the water toxins, traces of human activity. Because of this part of jellyfish extinct, some just migrated with permanent habitats and went close to the shore. As a rule, jellyfish come to the shore of the Sevastopol in the middle of autumn, when storms begin. And why are they there now remains to be seen.