CATDOLL : CATDOLL: What is the life span of a fish?

Due to the influence of natural factors and human fishing, most fish cannot complete their entire life cycle and die of old age. Therefore, it is difficult for us to know their physiological lifespan, and we can only understand their ecological lifespan. The usual practice is to judge their lifespan based on the annual rings on the body tissues (such as scales, otoliths, fin rays, fin bones, gill covers, vertebrae, etc.) of the largest individual caught (fish grow throughout their lives, the larger the individual, the older it is).

Generally speaking, the life span of fish is related to its individual size and the age of sexual maturity. The larger the fish is, the later it matures, and the longer its life span is. From this perspective, the world's largest fish, the whale, should have the longest life span. Unfortunately, so far, people know nothing about its life span. It is reported that the European sturgeon living in the Caspian Sea and the Black Sea can weigh up to 1,500 kilograms and live for more than 100 years; and the white sturgeon in the Yangtze River in my country has a life span of nearly 100 years. Many small fish, such as the false goby, herring, and silver fish in freshwater, have a life span of only about one year. Although the life span of fish varies greatly among species, the life span of most fish is concentrated between 2 and 20 years, of which 60% are concentrated between 5 and 20 years. No more than 10% of fish can live for more than 30 years, and only 5% live for less than 2 years. Among the freshwater fish in my country, the life span of silver carp, minnow, redfin whitefish, copper fish, yellow catfish, silver carp, and sand snakehead is between 2 and 4 years; the life span of black carp, grass carp, silver carp, bighead carp, crucian carp, bream, redfin whitefish, and mandarin fish is mostly between 7 and 8 years, and some can live for more than 10 years. The life span of marine fish is shorter.

In addition, the life span of the same species of fish varies in different environments. For example, yellow croaker can live for 29 years in coastal Zhejiang, but only 17 years in coastal Fujian and Guangdong, and only 9 years in the eastern waters of Hainan.