PROBLEM TO BE SOLVED: To provide a floating tank which: protects larval fish from concentrating in a portion of the floating tank； enables sufficient oxygen to be supplied to all the larval fish cultured inside the floating tank； can keep water temperature low by increasing the quantity of water； and prevents a burden due to an increase in the quantity of water from being placed on the larval fish.SOLUTION: A floating tank 1 includes a hatching and cultivating chamber 10A in which a water flow is formed upward from below, within a body frame 10. In the hatching and cultivating chamber 10A, there are arranged in layers a plurality of cultivating plates 2 vertically separating the hatching and cultivating chamber 10A at set intervals and cultivating larval fish thereon. In the cultivating plate 2, there are arranged at intervals one or a plurality of passing openings 20 allowing the larval fish to pass therethrough and in which the water flow is formed.【課題】浮上槽内の一部に仔魚が密集するのを防ぎ、浮上槽内で育成される全ての仔魚に十分な酸素供給を行うことができ、用水の水量を増やして水温を低温に保つことができると共に、用水の水量が増えた場合にも仔魚に負担が掛からないようにする。【解決手段】本体枠１０内に下方から上方に向けて水流が形成される孵化育成室１０Ａを備えた浮上槽１であって、孵化育成室１０Ａには、孵化育成室１０Ａを設定間隔で上下に区画して板上で仔魚を育成する複数の育成板２が積層配置されており、育成板２には、仔魚が通過でき且つ水の流れが形成される通過口２０が一つ又は間隔を空けて複数配置されている。【選択図】図１
