The back of the body is dark gray or yellowish brown, the side is slightly yellow-green, and the abdomen is light gray or silvery white. Carp is a fish of CYPRINIDAE and CYPRINIDAE, with dark gray or yellowish brown back, yellow-green side and light gray or silvery white abdomen. Carp is a freshwater pelagic fish, which is omnivorous. It has strong adaptability to the living environment, inhabits the bottom of water, has mild temperament, vigorous vitality, cold tolerance, hypoxia tolerance and salt tolerance, and grows well in salt water below 7g/L. The optimum salt content is1~ 4g/L. The optimum water temperature is between 20 ~ 32℃, and the optimum water temperature for cultivation is 22 ~ 28℃. The optimum pH value for growth is 7.5 ~ 8.5.