Method for marking fish otolith by fluorescent substances

The invention relates to a method for marking fish otolith by fluorescent substances. According to the method, tetracycline hydrochloride is dissolved in water bodies, and marked solution of tetracycline hydrochloride solution is obtained; and fishes to be marked are put into the solution for soaking, and the marking of the fish otolith is completed. The tetracycline hydrochloride is adopted as the marking solution for soaking the fishes, the marking operation is completed, and the strong stress response damage and the fish body mechanical injury caused by artificial operation in the existing marking method are overcome; the investment of labor and materials is reduced; and the problem of high external hanging marker loss rate is solved. The method has the advantages that the cost performance is high, the operation is convenient, the soaking concentration and time can also be regulated according to different fishes, specifications and numbers, and the method belongs to a marking method capable of being applied to large-scale economic fish release.