What are the types of jellyfish? The main varieties of marine and freshwater jellyfish

Jellyfish is a very common and most amazing species of living creatures inhabiting the seas and oceans. They can admire endlessly. What kinds of jellyfish are, where they live, what they look like, read in this article.

General information about jellyfish

They relate to coelenterates and are part of their life cycle, which is of two stages: asexual and sexual. Jellyfish adults are dioecious, their reproduction occurs sexually. The role of the male is to sweep the sexual products into the water, which can immediately fall into the corresponding organs of the female or be fertilized directly in the water. It depends on the variety of jellyfish. Appearing larvae are called planulas.

They have the ability to exhibit phototaxis, that is, they move towards the light source. Obviously, they need to stay in the water for a while, and not to fall immediately to the bottom. Freely moving life of the planets lasts not for long, about a week. After that, they begin to settle to the very bottom, where they attach to the substrate. Here they are transformed into a polyp or a scythist, whose reproduction occurs by budding.

This is called asexual reproduction, which can be carried out indefinitely, until there are favorable conditions for the formation of jellyfish. Gradually, the body of the polyp acquires transverse constrictions, then the process of strobilization and formation of young disc jellyfish ester occurs.

They are most of the plankton. Later they grow up and become adults jellyfish. Thus, for asexual reproduction - budding, the water temperature may be low. But, having overcome a certain temperature barrier, dioecious jellyfish are formed.

Class of hydroid jellyfish

Coelenterates include single or colonial water inhabitants. Almost all of them are predators. Their food is plankton, larvae and fish fry. The intestinal forms of jellyfish have ten thousand species. They are divided into classes: hydroids, scyphoid and coral polyps. The first two classes are usually combined into a subspecies of jellyfish.

Hydroid coelenterate jellyfish are characteristic representatives of freshwater polyps. The place of their habitual habitat are lakes, ponds and rivers. The body has a cylindrical shape and the sole is attached to the substrate. The opposite end is crowned with a mouth with tentacles around it. Fertilization occurs within the body. If the hydra is cut into many pieces or turned to the other side, it will continue to grow and live. The length of her body is green or brown, reaching one centimeter. Hydra does not live long, only one year.

Scyphoid jellyfish

They are free-floating and have different sizes. The size of some species is only a few millimeters, and others - two or three meters. An example is cyanine. Its tentacles can stretch for twenty meters in length. The polyp is poorly developed or completely absent. The intestinal cavity divides the partitions into chambers.

Scythian jellyfish can live up to several months. Approximately two hundred species of habitat are temperate and tropical waters of the World Ocean. There are jellyfish that people eat. These are the coroners and aurelias, their salts. Many species of scythoid jellyfish cause burns and redness of the body, if you touch them. For example, chirodrofus causes even fatal burns in humans.

Medusa Aurelia eared

There are different kinds of jellyfish. A photo of one of them is presented to your attention. This scyphoid jellyfish Aurelius is eared. Her breathing is carried out by all the transparent and gelatinous body, in which there are twenty-four eyes. On the entire perimeter of the body there are sensitive corpuscles - the corpuscles. They perceive the impulses of the environment. It can be light.

The jellyfish consumes food and removes from the organism its remains by a mouth opening, around which are four oral blades. They have stinging cells containing a burning substance that serves as a jellyfish defense and helps to get food. Aurelia is not adapted to life on land, since it consists of water.

Medusa Cornerot

It is popularly called "Umbrella". The habitat of the jellyfish is the Black, Azov and Baltic Seas. Cornerot bewitches with its beauty. The body of the jellyfish is translucent with a blue or purple edging, resembling a lampshade or an umbrella. Its peculiarity is that most of the time it floats on its side and has no mouth. Instead of it on the blades are scattered holes of small diameter, through which it feeds. Cornerot lives and multiplies in the water column at great depths. If you accidentally come into contact with a jellyfish, you can get a burn.

Unusual habitat

Scientists from Israel have proved that freshwater jellyfish are found on the Golan Heights in lakes. They were first seen by children. Then some specimens were put in a bottle and handed over to Professor Gofen. He carefully studied them in the laboratory. It turned out that this is a local colony of one of the freshwater hydroid jellyfish, which in 1880 were described in England. Then these jellyfish were found in the basin with water tropical plants. According to the professor, the mouth of the jellyfish is surrounded by numerous stinging cells, which she catches planktonic organisms. For humans, these jellyfish are not dangerous.

Jellyfish freshwater

These coelenterates inhabit the waters of only the seas and oceans. But, there is one exception, called the freshwater Amazonian jellyfish. Its habitat is South America, namely the basin of a large river on the mainland - the Amazon. Hence the name. Today this species has spread everywhere, quite accidentally, during the transportation of fish from the seas and oceans. The jellyfish is very small, reaching only two centimeters in diameter. Now it inhabits slow, calm and stagnant waters, dams, canals. The feed is zooplankton.

The biggest jellyfish

It's cyanide or a lion's mane. In nature, there are different kinds of jellyfish, but this one is special. After all, it was described by Conan Doyle in his story. This is a very large jellyfish, the umbrella of which in diameter reaches two meters, and the tentacles - twenty. They look like a tangled ball of crimson red color.

In the central part the umbrella is yellowish, and its edges are dark red. The lower part of the dome is endowed with a mouth opening around which there are sixteen large folded oral blades. They hang down, resembling curtains. The cyanide moves very slowly, mainly along the surface of the water. It is an active predator, feeds on plankton organisms and small jellyfish. The habitat is cold water. It is common, but not dangerous. The resulting burns do not lead to death, but can cause painful redness.

Jellyfish «Lilac sting»

This species is widespread in the World Ocean with warm and temperate waters: it occurs in the Mediterranean and Kara seas, in the Atlantic and Pacific oceans. These species of jellyfish usually live away from the shore. But sometimes they can form flocks in the waters of coastal waters, and in huge numbers meet on the beaches. Jellyfish have not only a mauve color. They are golden yellow or yellow-brown, depending on the habitat.

Jellyfish Compass

These species of jellyfish their place of residence chose the coastal waters of the Mediterranean Sea and one of the oceans - the Atlantic. They live near the coast of Turkey and the United Kingdom. These are large enough jellyfish, their diameter reaches thirty centimeters. They have twenty-four tentacles, which are arranged in groups of three in each. Body coloration is yellowish-white with a brown tinge, and its shape resembles a saucer-bell, in which thirty-two lobes are defined, which are colored brown at the edges.

The upper surface of the bell has sixteen brown V-shaped beams. The lower part of the bell is the location of the oral opening, surrounded by tentacles in the number of four pieces. These jellyfish are poisonous. Their poison has a potent property and often leads to the formation of wounds, which are very painful and long to heal.