<;P>;PROBLEM TO BE SOLVED: To provide mixed feed for initial seedlings of useful herbivorous shellfish, showing an effect in high density raising by solving abundant depletion and growth stagnation caused by feed insufficiency and feed value decrease, and often occurring in raising the initial seedlings (shell length 0.5-3 mm) of useful herbivorous shellfish, and to provide a method for feeding the mixed feed. <;P>;SOLUTION: The mixed feed for initial seedlings of useful herbivorous shellfish has as the main ingredient, free-floating plant plankton effective to bivalve larva at high density, and as the collateral component, an animal protein-containing auxiliary material, in view of the first time found fact that the digestion mechanism and the cell structure concerned with digestion absorption of the initial seedlings of the edible vegetative useful shell are similar to those of bivalve larva. The initial seedlings of the edible vegetative useful shell are made of components of a size allowing easy feed intake with the mouth-parts. The mixed feed is supplied by mistily spraying to a raising substrate surface where the initial seedlings adhere and inhabit, in blob of a few mm diameter or below at close range of a few mm interval. <;P>;COPYRIGHT: (C)2010,JPO&INPIT