How to tell the age of goldfish

The age of goldfish is determined by its scales, annual rings on otoliths and body length composition.

1, look at the scale

Take a fish scale, wash it, and look at it carefully under a magnifying glass. There are rings on the surface, narrow and wide. How many groups of rings are wide and narrow on the scale, the age of the fish is how old. Scales are suitable for age identification of populations with simple age composition and rapid growth (such as goldfish), and the total coincidence rate of ring readings can reach 90.5%.

Step 2 look at the otolith

Calcareous stones in the inner ear of vertebrates or auditory vesicles of invertebrates are especially obvious in many teleost fish. Otoliths form a hard body and increase with the growth of fish. When it cuts the core, it can be found that the rings arranged in concentric circles are similar to those on fish scales, and the age of fish can be calculated according to the otolith rings.

Extended data

Other functions of fish scales

1. The scales in the belly of fish can reflect and refract bright light, just like a mirror, which dazzles the fierce aquatic animals below and produces a natural camouflage that does not distinguish things; The scales on the back are dark, similar to the color of the bottom of the water, so it is difficult to distinguish the natural enemies in the water.

2. It provides a protective barrier for fish, isolating it from many microorganisms around it, effectively avoiding infection and resisting diseases.

3. As an external skeleton, fish scales can not only keep the fish in a certain shape. In addition, biologists judge the age of fish according to the rings on the scales (each ring represents a winter); It can also correctly grasp its growth, death and health status.

4. Fish scales can reduce the friction between fish and water and reduce the resistance. But also make natural enemies (such as humans) miss and escape when they are caught.

Baidu encyclopedia-fish age identification

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