Screening technique of juvenile fish in brocade carp culture

When brocade carp juveniles grow to a certain stage, they must be screened from batch populations. In order to do a good job in the screening work, the area of the brocade carp juvenile pond should be about 2000 square meters (3.0mu). As the screening work is in the middle of summer, it should be carried out in the morning and completed by 10:00 at the latest, otherwise accidental damage will be caused by rising water temperature. The day before the netting and screening operation, the pond should be drained and the water level should be lowered.

Zhaohe tricolor can be screened from "black" (about 1 cm long) 7-15 days after hatching; Dazheng trichrome will appear dark black in the process of cultivation, although some of them are light ink, but it is better to retain them if they have better patterns. Red and white or Dazheng tricolor can be screened for the first time about 40 to 60 days after hatching; some appear light ink in autumn, but become brilliant ink by the Beginning of Spring; others do not turn black until they are 2 or 3 years old, or scarlet becomes more bright. In the screening work, it is necessary to grasp the genetic characteristics of all kinds of koi, and the screening criteria are based on the quality of carp. In the first screening, those with the genetic characteristics of their varieties should be retained. After that, after about 20 days, the second screening work was done and reared in ponds according to different varieties and specifications, in order to improve the survival rate of koi.