PROBLEM TO BE SOLVED: To provide a cultivation system of fish seedlings in which the production of seedlings being the same as flowing irrigation or further better than that can be obtained by seawater circulation.SOLUTION: A cultivation system of fish seedlings comprises a seedling production tank 2 having a water level adjustment tank 4 and a water quality management tank 3. The seedling production tank 2 is filled with seawater and receives fish seedlings therein, and has a fish spill prevention strainer 10, and also is brought into communication with the water level adjustment tank 4 through the strainer 10. The water quality management tank 3 receives multiple phytoplankton, animal plankton, nesting aquatic insects and marine algae in the inside filled with the seawater. The water quality management tank is provided with outflow piping 6a, 6b so that the seawater may flow out from the water level adjustment tank 4 to the water quality management tank 3, and is provided with inflow piping 7a, 7b so that the seawater may flow in from the water quality management tank 3 to the seedling production tank 2.SELECTED DRAWING: Figure 1【課題】掛け流しと同一またはそれ以上の良好な種苗生産を、海水の循環により得られる魚類種苗の育成システムを提供する。【解決手段】水位調整槽４を有する種苗生産槽２と、水質管理槽３を含み、当該種苗生産槽２は海水で満たされ、その中に魚類種苗を収容すると共に、魚類流出防止ストレーナー１０を有し、当該ストレーナー１０を介して前記水位調整槽４と連通し、前記水質管理槽３は、海水で満たされその中に複数の植物プランクトン、動物プランクトン、営巣性水生昆虫および海藻類を収容し、前記水位調整槽４から前記水質管理槽３へ海水が流出するよう流出配管６ａ、６ｂが設けられ、前記水質管理槽３から前記種苗生産槽２へ海水が流入するよう流入配管７ａ、７ｂが設けられていることを特徴とする魚類種苗の育成システムである。【選択図】図１
