Hydra - a special family, a member of the class of hydroids, cnidarians type.They live only in freshwater, mainly tightened with duckweed.They prefer to settle on the brightest areas of ponds and marshes, as like sunlight.They feed on water fleas, small mosquito larvae, fry, cyclops, vodoemnym plankton.
polyp Hydra is similar in size to a grain of barley.It is translucent, grayish hue.On the one hand it has a hole, which acts as the mouth and designed to extract waste products, surrounded by tentacles.On the other side is the so-called sole with which it sticks to the stationary water surface.
The body consists of two cell types - external and internal.All the interior - it's just the intestinal cavity.Respiration is carried throughout the body surface.
adopting a stable position, freshwater hydra freezes in anticipation of the victim.On the tentacles are tiny cilia that help to identify the approaching prey.On the surface of the body of the hydra, to a greater extent on the tentacles, there are cells with protruding hairs, containing a capsule of poison.In contact with the cell production, catching the poison kills her.Hydra tentacles pushes prey to the mouth and swallowed it.
polyp hydra - a real glutton.He is able to eat the amount of food three times greater than its own.Swallowed food directly into the intestinal lumen, where he quickly digested.
If one mining claim two hydra, they start to suck sacrifice on both sides.When contact is large, more powerful, smaller swallows.But the paradox, swallowed hydra does not die.After a while she is cast out of guts to swallow.Having been in the intestinal lumen kinsman, "otryahnuvshis", she finds a comfortable place, sticks and freezes in anticipation of food.
freshwater Hydra may reproduce in two ways: by budding (asexual) and division (sexual).In the first method, the body is formed at its one or more excrescences, which when mature, are separated from the "mother".For a month hydra is capable of creating up to 15 species of their own kind.This simple method is quite productive, as most of the children received thus survives.
second option reproduction used in case of shortage of food.In the context of malnutrition is the formation of sex cells.And on one particular way of male cells, and others - women.After fertilization, the egg is formed, while the adult dies, and the resulting egg sinks to the bottom of the pond.After lying for some time, because it can be formed in the spring of the hydra, but more often it dies.
freshwater polyp Hydra most of his life moving.If necessary, he may move by bending and moving the body sole.Finding a new home, it sucked.
polyp Hydra has a high ability to restore damaged or lost body parts (regenerated).When dissection of one individual into two parts, even irregular, becoming two of the hydra.Scientists have shown that theoretically immortal hydra.