If you are interested in biology, then you probably know about how you can determine the age of some species of animals and plants. So, in cattle, you can find out the age by the horns: each lived year leaves a ring. In a similar way, you can find out the age of the tree. By looking at the number of annual rings on his cut, you can find out up to a couple of years how many years ago it grew. But how do you know the age of the fish? This is especially interesting for fishermen who occasionally catch impressive specimens.
Well, that’s not so difficult. But first, it is necessary to refresh some biological aspects concerning these inhabitants of fresh and sea waters. Their body is covered with scales, which protects the fish from mechanical damage and parasites, and also serves as a "fairing", which improves the hydrodynamic characteristics of the fish, allowing it to move in the water column with greater speed. So, scales are a kind of analogue to saw cut wood. Asked about how to find out the age of the fish, you need to tear off one flake and look at it carefully.
The fact is that on the scales the same annual rings are formed, which can be seen on the saw cuts of trees or the horns of cows. By the width of the ring you can find out how the year was, if the fish had enough food. The wider the ring, the more favorable the conditions at that time. However, before you know the age of the fish, you should know which scales you need to take. Ideal scales from the middle of the sideline. Before determining the age, you need to dry it properly and count the rings under the magnifying glass.
However, how do you know the age of river fish that does not have scales on their bodies? These species include burbot and sterlet. In addition, in species such as ruffs, perch or pike, the scales are so small that they can only be viewed under a microscope, and in this case it is not surprising to make a mistake. To solve this problem, you must resort to using another method.
So, for perch, a dried gill cover is used to determine the age, years are considered in vertebrae in a ruff or burbot. In noble white fish, you can find out the age by cutting the rays of the front vertebrae, and previously they also need to be properly dried. But how do you know the age of the fish in this case? It's simple: the above body parts after drying need to be cut, and on the saw all the same annual rings will be clearly visible, which you need to focus on, determining the age of the fish.
Do not assume that the methods described by us are good only for freshwater fish. They are quite suitable for marine fauna, which often does not have scales or is too small. Those who are thinking about how to find out the age of sea fish should remember that it can take a lot of time to calculate its annual rings. So, several years ago, sea bass was caught near Alaska, whose age was estimated by biologists as much as 200 years!
However, according to a number of researchers, until recently catfish of even more venerable age could be caught in our rivers. Some scientists, however, believe that a number of deep-sea fish live almost forever, dying only from the elements or attacks of predators.
