<；P>；PROBLEM TO BE SOLVED: To easily and inexpensively produce a fish bank having a simple structure, facilitating the assembly, and providing excellent whirlpool effects and shadow effects by utilizing shells. <；P>；SOLUTION: The fish bank block 200 includes a concrete block body 1 which has a polygonal prism shape and a cavity 2 in the inside, and of which the periphery faces are opened 4 while leaving the ridge lines in columnar 3 shapes, and a water-permeable shell-holding case 6 inserted and fixed in the block body 1 while storing the shells in the interior. The shell-holding case 6 has a polygonal lower frame body 7 inserted into the block body 1 from the opening 4 and capable of being fixed to the block body 1, a water-permeable basket 9 fitted in the lower frame body 7 and allowing the shells to be packed from an upper opening 8, and a water-permeable lid 10 covering the upper opening 8 of the water-permeable basket 9. The lower frame body 7 has engaging members 12 protruded outward from outside corner parts, fitting in the side-part pillars 3a of the block body 1 to restrict the movement in the horizontal direction, and put on the bottom part pillars 3b of the block body 1 to restrict the downward movement. <；P>；COPYRIGHT: (C)2011,JPO&INPIT
