The four traditional freshwater domestic fish in my country are: herring, grass carp, silver carp and bighead carp.

It can be called a national treasure among the "big family" of farmed fish in our country. The theory of "four major fish" has a long history and great influence. It is a unique specialty of our country and has also been introduced and introduced by many countries in the world. Breeding has now taken root even in the United States, Canada and other countries, and is threatening to become a disaster. They are a common food fish found in ponds and are the most common freshwater fish species.

Due to their different feeding habits and habitat habits, these four kinds of fish are very suitable for mixed culture in a pond. They can make full use of natural bait and water space, have greater breeding benefits, and complement each other better. It is called a classic of fish polyculture and has gradually become the main traditional fish culture in my country.

The "four major fish" can reproduce naturally in natural waters with river currents. In artificially cultivated still water ponds, they cannot go into estrus and spawn like carp and crucian carp. artificial breeding.

Distribution range

Herring, grass carp (grass carp), silver carp and bighead carp (bighead carp) are customarily called the four major fish in China. In the past, these four types of fish could only reproduce in rivers under natural circumstances and could not spawn in still water ponds. China's main fry producing areas were originally the Yangtze River, Xiangjiang River and Xijiang River.

The Freshwater Fisheries Research Laboratory of the former South China Sea Fisheries Research Institute of the Ministry of Fisheries (now the Pearl River Fisheries Research Institute of the Chinese Academy of Fisheries Sciences) began to study artificial breeding of domestic fish in 1953. In 1958, artificial breeding of silver carp and bighead carp in ponds was successful for the first time. Since then, artificial breeding of herring and grass carp has also been successful.

The key technology is: adopting a broodstock breeding method that combines nutritional physiology and ecology to promote the full development of the gonads of the broodstock; under certain ecological conditions, injecting an appropriate amount of exogenous hormones to promote the eggs of the broodstock to reach physiological levels. Mature, allowing for egg laying and fertilization.

The success of artificial breeding of the four major species of fish has eliminated the long-term dependence on catching natural fry, provided the seeds needed for breeding, and greatly promoted the development of China's freshwater fisheries. The principle also applies to the artificial breeding of other fish. This achievement is in a leading position in the world and won the National Invention Award in 1965.