Do they drink fish or not? What does science say?

Having studied all aspects of the problem, the learned men found out that the fish were not drinking at all the same. Even better to say - do not drink, but get water in your body. After all The liquid participates in all exchange processes. Without it life would be impossible. That's what they did.

Freshwater inhabitants

These beauties in their bodies have so many salts that they do not need to swallow water to ensure metabolism. It turns out that they drink fish body, not mouth. Schematically, the process can be represented as follows. If two liquids are next to each other, differing in the concentration of salts dissolved in them, open the damper, then where will the diffusion vector be directed? Correctly, in the direction of a more saturated liquid. The more the concentration of salts, the more "thirst" torments. Water begins to move towards a saturated solution. Fresh water contains a small amount of additives, its osmotic pressure is almost zero. And fish - on the contrary. There are a lot of salts in their bodies. It turns out that they constantly suck in the environment. And their main task Is not absorption, but excretion. This process is established, otherwise freshwater inhabitants can swell and burst, so much flow into the body. It turns out that the fish are drunk in a very original way. They absorb the fluid for their own needs, and even regulate its pressure inside.

Sea inhabitants

These inhabitants of saline waters have the reverse process. In the sea, the concentration of salt is high. The osmotic pressure is equal to thirty-two atmospheres. Sea fish drink continuously. They simply have to constantly replenish their supplies, because the environment constantly "dries" them, water seeps out through the whole body. The fact is very comical. When sea fish drink water - they are alive and well. They stop - they can "dry up", die from losing fluid. And this, being constantly in the water! But these are the laws of diffusion. Osmotic pressure inside fish bodies is only ten to fifteen atmospheres. Outside - more than twice as high. That's what poor fish need to drink continuously to survive and not "wither." It is interesting that they need fresh water for their life. They "filter" it, removing the remnants of salts through gills. The same can do, for example crocodiles. They remove salts through Lacrimal glands. When a crocodile sweetly encroaches, he cries. This excess salt leaves the body.

Sharks and rays

These inhabitants of the world ocean were allocated to a special class. The reasons for this "prejudiced" attitude are that the mechanisms of their relationship with the environment are very different from other inhabitants of the sea depths. Named fish are not so much consumed as the rest. They "learned" differently to cope with the problem of the difference in osmotic pressure. They retain urea in their circulatory system, although this is very harmful. These creatures even have a special shell in the gills - protection from excess salts. Thus, skates and sharks maintain an internal concentration of salts higher than in the surrounding space. Scientists believe that this is an indicator of the antiquity of these inhabitants of the seas. They, like freshwater, suck liquid all over the body.

Why fish can not live in any environment

The difference in the mechanisms of interaction with liquids does not allow them to master the entire space of the world's ocean. Those who are well in fresh water will die in the sea. And vice versa. There are exceptions to this rule. So, everyone knows that a part of fish lives well in salt water, but reproduces in rivers. That is, they are diadromous - they can live in any environment. Whether the fish drink water in this case depends on the state of the surrounding liquid. They feel the body, in which direction the process has moved, and in case of need start to consume water. Their internal organs quickly Rebuilt under the environment. For example, diadromous are salmon, puzanki, sturgeon and some other fish. While they splash in the sea - they drink just like all its inhabitants. When sent to spawn, their gills quickly adjust to the environment. Therefore, they do not die from the transition to water with a different concentration of salts. The reverse process takes place in the body of their fry when they descend into the natural habitat-the sea.

It is interesting

Scientists have found another inhabitant, who can adjust the water balance in an original way. The frog-crabbeard - a newly discovered amphibian - leads a strange way of life. She lives in the sea, and multiplies in a fresh environment. How is this possible? For this, nature invented a special mechanism. In order not to perish, it can regulate the level of urea in the blood. When diving in the sea - accumulates it. Will gather to throw eggs - get rid of urea. And small frogs, when they grow up, also learn to use this mechanism for their journey between water bodies. These are the wonders of nature!

It turns out that it is impossible to answer unequivocally the question whether fish drink. Naturally, they, like any living organism, need moisture. Only they get it in their own way, as provided by natural mechanisms.