<；P>；PROBLEM TO BE SOLVED: To rear a floating larva of the whole bivalve with high density with high efficiency by removing leavings such as excretion, dead shellfish and remnants of baits at the bottom of a water tank without contaminating a floating larva under breeding with them. <；P>；SOLUTION: A plurality of rearing water tanks A, B for storing rearing water are provided so that they are selectively used； each rearing water tank is provided with a cleaning means 7, 15 for cleaning inside the rearing water tank and a discharge path 30, 35 for discharging rearing water at the time of cleaning； and a larva-transfer path 40 is connected to a position which is situated between one rearing water tank A and the other rearing water tank B and is higher than the water level L of the rearing water at the time of rearing with a larva transfer path valve interveningly provided so that a floating larva can be transferred with rearing water from one rearing tank to the other rearing tank through the larva transfer path by increasing rearing water in the one rearing water tank. <；P>；COPYRIGHT: (C)2009,JPO&INPIT
