Polyp hydra is a rare glutton

Hydra is a special family that belongs to the class of hydroids polyps, a type of coelenterates. They live only in freshwater reservoirs, mostly tightened with duckweed. They prefer to settle in the brightest places of ponds and marshes, because they love sunlight. They feed on water fleas, small larvae of mosquitoes, fry, cyclops, water plankton.

Polyp hydra in size is similar to barley grain. It is translucent, grayish in color. On the one hand, it has a hole that performs the functions of the mouth and is designed to extract the products of vital activity, surrounded by tentacles. On the other hand, there is a so-called sole, with which it is sucked to a surface fixed in water.

The body consists of two kinds of cells - external and internal. The whole interior is only the intestinal cavity. Breathing is carried out by the entire surface of the body.

Having assumed a stable position, the freshwater hydra stops in anticipation of the victim. On the tentacles there are small cilia that help to identify the approaching prey. On the surface of the body, hydras, mostly on tentacles, have cells with a protruding hairs containing a capsule with poison. When the prey is in contact with such a cell, the excreted poison kills it. Hydra tentacles pushes the prey to the oral cavity and swallows it.

Polyp hydra is a real glutton. He is able to eat a volume of food three times his own. Swallowed food immediately enters the intestinal cavity, where it is quickly digested.

If two hydras claim for one prey, they start sucking the victim from two sides. At the contact, a larger, stronger one swallows a smaller one. But the paradox, swallowed hydra does not die. After a while it erupts from the interior of the swallowed. Having visited the intestinal cavity of the congenital, "shaking off", she finds a convenient place, suckles and stops in anticipation of food.

Hydra freshwater can reproduce in two ways: by budding (sexless) and by division (sexual). In the first method, one or several growths are formed on her body, which, when ripe, are separated from the "mother". For a month the hydra can create up to 15 similar individuals. This simple method is quite productive, since most of the children thus obtained survive.

The second variant of reproduction is used in case of shortage of food. Under malnutrition, the formation of sex cells takes place . And on some individuals, male cells are formed, and on the other - female. After fertilization an egg is formed, the adult specimen dies, and the formed egg descends to the bottom of the reservoir. After lying for a while, hydra may form from it in spring, but more often it dies.

The freshwater polyp hydra is immobile for most of the life. If necessary, it can move, bending the body and moving the sole. Finding a new home, sucked.

Polyp hydra is characterized by a high ability to repair damaged or lost parts of the body (regenerate). When a single individual is cut into two parts, even unequal, two hydras become. Scientists have proved that theoretically hydras are immortal.