In general, the lifespan of a fish is related to its individual size and age at sexual maturity. The larger the fish and the later the age of sexual maturity, the longer the lifespan. From this point of view, the world's largest fish - the whale should have the longest lifespan. Unfortunately, so far, people know nothing about its lifespan. It is reported that the sturgeon living in the Caspian Sea and the Black Sea can weigh up to 1,500 kilograms and have a lifespan higher than 100 years; and the white sturgeon in China's Yangtze River has a lifespan close to 100 years. Many small fish, such as freshwater fish false tiger fish, mackerel will, silverfish, life expectancy is only about one year. Although the life expectancy of fish varies greatly between species, but the vast majority of fish life expectancy is concentrated in the 2 to 20 years, of which 60% are concentrated in 5 to 20 years, can live to more than 30 years of fish will not be more than 10%, and 2 years of the following only 5%. Among the freshwater fish in China, the life span of silver floating fish: arowana, redfin whitefish, copperhead, catfish, yellow catfish, silver catfish, and snakehead is between 2 and 4 years; the life span of cyprinid, grass carp, silver carp, bighead carps, crucian carp, pomfrets, redfin whitefish, and mandarin fish is between 7 and 8 years, and individual fish can live for more than 10 years. The life expectancy of marine fish is a little shorter.