Abstract: Problems to be solved by the present invention are: (i) to make it possible for bred fishes, such as tuna, to swim fully and safely without danger of collision to the wall; (ii) to make it possible for fry to safely survive without being eaten by young and grown fishes; (iii) to largely reduce energy consumption needed for water purification; and (iv) to largely reduce labor needed for cleaning and regenerating filter means. These problems are solved by the invention of equipment for migratory fish breeding, in which a breeding tank formed in a circle and a purified water tank formed in a shape lacking a part of a circle (an “occulted circle”) are included, both tanks closely set together like a pair of eye-glasses. The breeding tank is provided with water lanes for separating infant (fry), young, and grown fishes from each other, each given a circular water current. In the purified water tank, there is placed water filtering means and purified (filtered) water is stored there.