After examining all aspects of the problem, pundits have found that fish do not drink the same way. Even better to say - do not drink, but get water into your body. Cause
fluid is involved in all metabolic processes. Without it, life would be impossible. Here's what they came up with.
Freshwater inhabitants
These beauties have so many s alts in their bodies that they do not need to swallow water to ensure their metabolism. It turns out that fish drink with the body, not with the mouth. Schematically, the process can be represented as follows. If two liquids are placed side by side, differing in the concentration of s alts dissolved in them, and the damper is opened, then where will the diffusion vector be directed? That's right, in the direction of a more saturated liquid. The greater the concentration of s alts, the greater the "thirst" torments. Water begins to move towards a saturated solution. Fresh water contains a small amount of additives, its osmotic pressure is almost zero. But fish are the opposite. There are a lot of s alts in their body. 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 mayswell and burst, so great is the flow into the body. It turns out that the fish drink in a very original way. They absorb liquid for their own needs, and even regulate its pressure inside them.
Sea inhabitants
The process is reversed for these inhabitants of s alt waters. The s alt concentration in the sea is high. The osmotic pressure index is thirty-two atmospheres. Marine fish drink continuously. They simply have to constantly replenish their reserves, because the environment constantly “dries” them, water seeps out through the whole body. The fact is very comical. When marine fish drink water, they are alive and well. They stop - they can "dry", die from fluid loss. And this, being constantly in the water! But such are the laws of diffusion. The osmotic pressure inside fish bodies is only ten to fifteen atmospheres. Outside - more than twice as high. So the poor fish have to drink continuously in order to survive and not “dry out”. Interestingly, they need fresh water to live. They "filter" it, removing s alt residues through the gills. The same can be done, for example, crocodiles. They remove the s alts through
lacrimal glands. When a crocodile eats sweetly, it cries. It is excess s alts that are excreted from the body.
Sharks and rays
These inhabitants of the oceans were singled out in a special class. The reasons for this "biased" attitude is that the mechanisms of their relationship with the environment are very different from other inhabitants of the deep sea. These fish do not drink as much as the rest. They "learned"otherwise deal with the problem of osmotic pressure difference. 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 s alts. Thus, rays and sharks keep the internal concentration of s alts 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, absorb liquid with their whole body.
Why fish can't live in any environment
The difference in the mechanisms of interaction with liquids does not allow them to master the entire space of the oceans. Those who do well in fresh water will die in sea water. And vice versa. There are exceptions to this rule. So, everyone is well aware that some fish live well in s alt water, and breed in rivers. That is, they are diadromous - they can live in any environment. Whether fish drink water in this case depends on the state of the surrounding liquid. They feel with their body in which direction the process has moved, and, if necessary, begin to consume water. Their internal organs quickly
rebuild for the environment. For example, salmon, shad, sturgeon and some other fish are diadromous. While they are splashing in the sea, they drink just like all its inhabitants. When they go to spawn, their gills quickly adapt to the environment. Therefore, they do not die from moving into water with a different s alt concentration. The reverse process occurs in the body of their fry when they descend into their natural habitat - the sea.
This is interesting
Scientists have found moreone inhabitant who knows how to regulate the water balance in an original way. The crabeater frog, a newly discovered amphibian, leads a strange life. She lives in the sea, and breeds in a fresh environment. How is this possible? For this, nature has invented a special mechanism. In order not to die, it can regulate the level of urea in the blood. When he dives into the sea, he accumulates it. Willing to spawn - gets rid of urea. And little 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 unambiguously the question of whether fish drink. Naturally, they, like any living organism, need moisture. Only they receive it in their own way, as provided by natural mechanisms.
