实践证明,鱼苗投放以封冻前为好。但无论何时投放,鱼苗的优劣必须仔细鉴别。比较简单的鉴别方法是将鱼放在盛水的白瓷盘中,根据鱼的体形、状态、眼睛大小、体色深浅、色素分布、鳔的形状及鱼苗在水中游泳姿态等加以区别,并确定鱼苗成色的优劣。1.家鱼苗与野鱼苗的鉴别:家鱼苗鱼 Practice has proved that the fish fry before delivery as well. However, no matter when the launch, the pros and cons of fry must be carefully identified. The relatively simple identification method is to place the fish in a white porcelain dish containing water and make a distinction according to the shape, state, eye size, body color depth, pigment distribution, the shape of the fishes and the swimming posture of the fry in the water, and determine Pros and cons of fry color. 1 home fry and wild fry identification: fish fry