China's four major fishes are cyprinids, grass carp, silver carp and bighead carp.

Before the Tang Dynasty, carp was the most widely farmed freshwater fish. However, because the Tang royal family was surnamed Li, the breeding, catching and selling of carp were banned. Fishermen had to engage in the production of other species, which gave rise to the four major fish: green carp, grass carp, silver carp and bighead carp.

The bighead carp is also called the silver carp. In the waters of the upper activities, eat green algae and other phytoplankton; bighead carp head is larger, commonly known as "fat head fish", also known as silver carp. It inhabits the middle and upper layers of the water and eats protozoa, daphnia and other zooplankton.

Grass carp live in the middle and lower layers of the water, swallowing the vegetation in the water and then discharging it, and then eating the feces after it has grown microorganisms and filtered them; mackerel live in the bottom layer of the water, eating mollusks such as snails, clams, and mussels; the mixing of these four kinds of fish can increase the utilization rate of the bait and the production of fish.

Bighead Carp Related Information

Bighead carps are 89-425 millimeters long. The body length is 3.1-3.5 times the body height and 2.8 to 3.4 times the head length. The body is slightly high and laterally compressed, with a narrow leathery rib on the ventral margin from the base of the ventral fin to the anus. Head large, head longer than body height, rather broad anteriorly. Head 3-4.2 times as long as snout, 5.8-7.4 times as long as eye diameter. Mouth terminal, broadly rounded, with sloping slit, ending up to just below the anterior margin of the eye.

Eyes small, situated below lateral median axis of head. Gill rakers numerous, fenestrated, closely arranged but not united. The pharyngeal teeth are arytenoid, with smooth surfaces. Scales fine. Dorsal fin short, starting closer to the base of the caudal fin, without hard spines. Caudal fin deeply forked. Swimbladder two-celled. Peritoneum black. Dorsal and upper part of body blackish, abdomen silvery white, body measurements with many irregular black spots, each fin grayish white and with small black spots.

Refer to Baidu Encyclopedia - Tetraodontiformes for more details