The age of a person is determined by the number of years he has lived, the age of the tree is the number of annual rings that can be seen on the cut, but how can you determine the age of the fish? Let's try to understand this issue.
How to know the age of fish on the scales?
Determining the age of fish is quite a difficult task, because the fish's life conditions can be different, so neither size nor coloring can give an accurate answer to the question. The most common method is to determine the age by scales. The caught fish takes several scales, which are cleared of mucus, dried and studied under a magnifying glass. The fact is that the structure of the fish scales is not uniform, on its surface it is possible to find a number of ridges and valleys, which, like the annual rings of a tree, form annual rings of fish. Such rollers are called sclerites. Usually for a year, two layers of sclerites form in the fish: a large one, which indicates active growth of fish in spring and summer and a small one that has grown over the winter and autumn. Counting the number of such double sclerites on the scales, you can approximately determine the age of the caught fish. However, some fish species have either too small scales or do not have it at all. For such fish, the definition of age occurs over the bones, but an ordinary person will be problematic enough to do this.
Determining the age of aquarium fish
If you yourself are breeding aquarium fish, you should know approximately how old they are. If you want to buy fish in a pet store, it is very difficult even to approximately determine their age, since the size, color of the fish can vary depending on temperature, water quality, feed and much more. Those who have long kept fish in their aquarium , with careful observation, may in due course notice signs of aging of the fish - its color becomes less pronounced, it moves slowly along the aquarium, often old fish lose their appetite. But all this should happen not overnight, otherwise the probability is great that the fish is just sick.