Jellyfish are a very common and most amazing species of living creatures that inhabit the seas and oceans. They can be admired endlessly. What types of jellyfish are, where they live, what they look like, read in this article.
General information about jellyfish
They belong to the coelenterates and are part of their life cycle, which has two stages: asexual and sexual. Jellyfish adults are dioecious, their reproduction occurs sexually. The role of the male is to sweep the reproductive products into the water, which can immediately enter the corresponding organs of the female or be fertilized directly in the water. It depends on the type of jellyfish. The larvae that emerge are called planulas.
They have the ability to exhibit phototaxis, that is, they move towards a light source. Obviously, they need to be in the water for some time, and not immediately fall to the bottom. The free-moving life of the planula does not last 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 scyphistoma, the reproduction of which occurs by budding.
Thiscalled asexual reproduction, which can be carried out indefinitely until favorable conditions for the formation of jellyfish come. Gradually, the body of the polyp acquires transverse constrictions, then the process of strobilization occurs and the formation of young disk jellyfish - ethers.
They are most of the plankton. Subsequently, they grow up and become adult jellyfish. Thus, for asexual reproduction - budding, the water temperature may be low. But, having overcome a certain temperature barrier, dioecious jellyfish are formed.
Class of hydroid jellyfish
Centers include solitary or colonial aquatic inhabitants. Almost all of them are predators. Their food is plankton, fish larvae and fry. Intestinal species of jellyfish number ten thousand species. They are divided into classes: hydroid, scyphoid and coral polyps. The first two classes are usually combined into a subspecies of jellyfish.
Hydroid intestinal jellyfish are characteristic representatives of freshwater polyps. Their habitats are lakes, ponds and rivers. The body has a cylindrical shape and the sole is attached to the substrate. The opposite end is crowned with a mouth with tentacles located around it. Fertilization takes place inside the body. If the hydra is cut into many pieces or turned inside out, it will continue to grow and live. The length of her body is green or brown in color reaches one centimeter. Hydra does not live long, onlyone year.
Scyphoid jellyfish
They are free-floating and have different sizes. The size of some species is only a few millimeters, while others are two to three meters. An example is cyanide. Its tentacles can stretch up to twenty meters in length. The polyp is poorly developed or completely absent. The intestinal cavity is divided into chambers by partitions.
Scyphoid jellyfish can live up to several months. Approximately two hundred species inhabit the temperate and tropical waters of the oceans. There are some jellyfish that people eat. These are cornerots and aurelias, they are s alted. Many types of scyphoid jellyfish cause burns and redness of the body if touched. For example, hirodrofus causes even fatal burns in humans.
Medusa Aurelia eared
There are different types of jellyfish. A photo of one of them is presented to your attention. This is the scyphoid jellyfish Aurelia eared. Her breath is carried out by the whole transparent and gelatinous body, in which there are twenty-four eyes. Along the entire perimeter of the body are sensitive little bodies - ropalia. They perceive the impulses of the environment. It could be light.
Medusa eats food and removes its remains from the body through the mouth opening, around which there are four mouth lobes. They have stinging cells containing a burning substance that serves as a defense for the jellyfish and helps to get food. Aurelia is not adapted to life on land, as it consists of water.
MedusaCornerot
She is popularly called "Umbrella". The habitat of the jellyfish is the Black, Azov and B altic Seas. Cornerot captivates with its beauty. The body of the jellyfish is translucent with a blue or purple edging, reminiscent of a lampshade or umbrella. Its peculiarity is that most often it swims on its side and does not have a mouth. Instead, small diameter holes are scattered on the blades through which it feeds. Cornerot lives and breeds in the water at great depths. If you accidentally come into contact with a jellyfish, you can get burned.
Unusual habitat
Scientists from Israel have proven that freshwater jellyfish are found in the Golan Heights in lakes. Children saw them for the first time. Then individual copies were placed 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 were described in England as early as 1880. Then these jellyfish were found in a pool with aquatic tropical plants. According to the professor, the mouth opening of the jellyfish is surrounded by numerous stinging cells, with which it catches planktonic organisms. For humans, these jellyfish are not dangerous.
Freshwater jellyfish
These intestinal inhabitants inhabit the waters only of the seas and oceans. But, there is one exception, called the Amazonian freshwater 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, and quite by accident, during the transport of fish fromseas and oceans. The jellyfish is very small, reaching only two centimeters in diameter. Now it inhabits slow, calm and stagnant waters, dams, canals. The food is zooplankton.
The biggest jellyfish
This is cyanide or lion's mane. In nature, there are different types of jellyfish, but this one is special. After all, it was her who was described by Conan Doyle in his story. This is a very large jellyfish, whose umbrella reaches two meters in diameter, and twenty tentacles. They look like a tangled ball of crimson red.
In the central part of the umbrella is yellowish, and its edges are dark red. The lower part of the dome is endowed with a mouth opening, around which there are sixteen large folded oral lobes. They hang down like curtains. Cyanea moves very slowly, mainly on the surface of the water. It is an active predator, feeding on planktonic organisms and small jellyfish. Habitat - cold waters. Common, but not dangerous. The resulting burns are not fatal, but can cause painful redness.
Purple Sting Jellyfish
This species is common in the World Ocean with warm and temperate waters: found in the Mediterranean and Kara Seas, in the Atlantic and Pacific Oceans. These types of jellyfish usually live far from the coast. But sometimes they can form flocks in the coastal waters, and meet in large numbers on the beaches. Jellyfish are not only mauve in color. They are golden yellow or yellow brown, depending on where they live.
JellyfishCompass
These species of jellyfish chose the coastal waters of the Mediterranean Sea and one of the oceans, the Atlantic, as their place of residence. They live off the coast of Turkey and the United Kingdom. These are quite large jellyfish, their diameter reaches thirty centimeters. They have twenty-four tentacles, which are arranged in groups of three each. The color of the body is yellowish-white with a brown tint, and its shape resembles a saucer-bell, in which thirty-two lobes are defined, which are colored brown at the edges.
The top surface of the bell has sixteen V-shaped brown rays. The lower part of the bell is the location of the mouth opening, surrounded by four tentacles. These jellyfish are poisonous. Their venom is potent and often results in wounds that are very painful and take a long time to heal.
