How do you calculate the age of a fish? How to know the age of the fish

The growth rings of fish are on the scales. Due to the high temperature and sufficient bait in spring and summer, the scales grow quickly and form wide concentric circles; In autumn and winter, the water temperature is low, the bait is scarce, and the scales grow slowly, leaving only narrow concentric circles. There is a clear boundary between the wide and narrow concentric circles.

How do you tell the age of a fish?

A simple way is to take a piece of the scales of a fish that has grown for many years and look at it under a microscope or magnifying glass, and you will see that the surface of the scales has black and white ring-like stripes, which resemble the growth rings on the cross-section of a tree. At this time, just carefully count the number of laps of the black ring stripes of the scales, and add another 1, which is the actual age of the fish.

For example, if there are 4 black circles on the scales, the actual age of the fish is 5 years. However, not all fish have growth rings on scales, such as salmon with rings on the gill cover, flounder with rings on the vertebrae, sharks with rings on dorsal fins, and large and small yellow croaker with rings on ears.

The method of judging the age of a fish is similar to that of a tree, both by the rings;

If you look closely, you can find that there is a ring line on each scale of the fish, which is the annual ring of the fish;

The distance between the ring lines is wide and narrow, because the growth speed of fish in each season is different: fast growth in spring and summer, wide ring width, light color; Autumn and winter grow slowly, with narrow rings and dark colors.

Also, the thicker the scales, the older the fish.

Most of the fish that live in the water also have "growth rings". The age of a fish can be determined by inference based on the scales, vertebrae, operculum, pectoral fin, dorsal fin, otoliths, and other parts of the fish. For example, salmon from northeastern China use gill operum to estimate age, flounder from China's coastal areas uses vertebrae to calculate age, fierce sharks use dorsal fins to estimate age, and the famous yellow croaker uses otoliths to estimate age.

In addition, fish generally use scales to mark their growth rings.

Fish produce growth rings, mainly due to the cyclical changes of nature year after year, which determines the growth of fish. Changes in the growth of the fish leave clear marks on the scales. In spring and summer, fish have abundant bait and high water temperature, which is the peak growing season, fish grow fast, and the scales also grow fast, producing very bright and wide concentric circles, and the distance between the circles is long, which biologists call "summer rings".

In autumn and winter, the water temperature drops, the amount of bait in the water decreases, and the growth of fish slows down, so the growth of scales also slows down, resulting in very dark and narrow concentric circles, and the distance between the circles is close, which biologists call "winter rings". This width and narrowness represent a summer and a winter. By the time the fish broadband reappeared the following year, there was a clear dividing line between the narrow band and the broadband.

This is the growth rings of fish. The age of the fish can be estimated from the number of concentric circles on the scales.

The easiest way to do this is to deduce the length of the fish from the "growth rings" of the scales. This is somewhat similar to the rings of trees. Trees grow fast in summer and slow in winter; Reflected in the annual rings are concentric circles one wide and one narrow, that is, a year.

Fish are abundant in bait and grow vigorously in the summer, and eat less and grow slowly in the winter. These are reflected in concentric circles of varying width on the scales. The age of the fish can be judged by the number of concentric circles, and the speed of the fish can be seen from the width of the concentric circles.

Hello, there are many ways to judge the age of the fish, such as the scales on the fish, otoliths and other methods, compared to the scales of the fish, the accuracy of the otolith is higher, and the rest of the way depends on the species of the fish, such as the age of the flounder, which can be judged by looking at its vertebrae, and the salmon can look at its gill cover, and the shark can judge the age by its dorsal fin.

1. Judging by fish scales.

Peel off a piece of fish scales and place it under a magnifying glass or microscope to observe, you can find that there are black and white ring stripes on the surface of the scales, at this time, just carefully count the number of black ring stripes on the scales, and add another one, that is, the actual age of the fish. For example, if there are three black circles on the scales, then the actual age of the fish is four years old.

2. Fish produce annual rings.

It is mainly the cyclical changes of nature year after year that determine its growth. The scales of many bony fish evolve from the dermis into bone scales, which in turn are composed of many concentric rings, and the changes in the growth status of the fish leave clear traces on the scales. Fish grow at different rates throughout the year.

In general, it grows fast in spring and summer, slow in autumn, stops growing in winter, and resumes the following spring. The same is true for scales, which are wider in spring and summer, narrower in autumn, and stop growing in winter. Flakes of different widths are stacked on top of each other in an orderly manner, one after the other around the center, forming many bands of rings, which are called"Growth year zone"。

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For some novice fish farmers, it is difficult to accurately determine the true age of aquarium fish. Due to the different size and growth rate of the fish, it is important for novice aquarists to know their timing and age if they want to select healthy and high-quality aquarium fish.

To accurately determine the age of a fish, you can observe the changes in their scales. In the first year of life, most fish are covered in tiny scales of various sizes, which look like a cone with a cut off spire. thick in the middle, thin on the edges, the top layer is the smallest, but the oldest; The bottom layer is the largest, but the youngest.

When the fish are young, the scales will look immature, small, and the number will be smaller. As the fish grows up, new lamellae are formed on its surface, and the number of lamellae increases as the fish ages. So the older the fish, the thicker, harder, and larger scales will be.

In fact, there are other ways to look at the age of the fish besides looking at the scales. We know that some fish have scales, but there are also many fish that don't. Therefore, we can judge the age of the fish by looking at the spine, operculum, otoliths, etc.

Of course, the method of judging is similar to observing fish scales, which is to determine the age of fish by using the "growth rings" and "characteristics" formed by different growth periods of fish.

Scales are generally relied upon as markers.

Peeling off a piece of the scales of a fish waiting to be verified and looking at it under a microscope or magnifying glass reveals black and white ring-like stripes on the surface of the scales, like growth rings on the cross-section of a tree.

At this time, the actual age of the fish is only by carefully counting the number of laps of the black ring stripes on the scales, and adding one more. For example, if there are three black circles on the scales, then the actual age of the fish is four years old.

Usually the lifespan of a fish is 5-10 years. The birthday of fish is the pike. In 1947, a pike with a ring was caught in Germany, and the ring was engraved with its release date of 1680, according to which it is estimated that this fish has lived for at least 267 years, which can be called the "old birthday star" among fish.

In contrast, the shortest-lived fish is a transparent tigerfish, which is very short, from birth to death, in just one year.

Living environment: When fish are in a living environment that is not suitable for them, it is like people going to Qinghai-Tibet to have altitude sickness. However, the genes in its body cannot adjust the body's mechanisms, and there is no relevant auxiliary equipment to relieve physical discomfort like humans, so its lifespan is self-evident.

For example, the large yellow croaker can live for 29 years in the coastal areas of Zhejiang, while in the east coast of Fujian and Guangzhou, it usually has a lifespan of only 17 years, and it only lives for 9 years in the eastern waters of Hainan.

Usually the lifespan of a fish is 5-10 years. The birthday of fish is the pike. In 1947, a pike with a ring was caught in Germany, and the ring was engraved with its release date of 1680, according to which it is estimated that this fish has lived for at least 267 years, which can be called the "old birthday star" among fish.

In contrast, the shortest-lived fish is a transparent broken tiger fish, although it is not dying in the twilight of life, but its life is very short, from birth to death, it is only a year. <

Usually the lifespan of a fish is 5-10 years. The birthday star of the fish is the dog staring at the filial piety fish. In 1947, a pike with a ring was caught in Germany, and the ring was engraved with its release date of 1680, according to which it was estimated that this fish lived for at least 267 years, which can be called the "old birthday star" among fish.

In contrast, the shortest-lived fish is a transparent tigerfish, which is not born and dies, but it has a very short lifespan, from birth to death, in just one year.