PROBLEM TO BE SOLVED: To provide a water splash prevention tool which is mounted on the side plate of an aquarium fish water tank and preventing water splash in the water tank.SOLUTION: Water splash preventing tools 2, 3 are mounted on a water tank 1 having four peripheral side plates 11, 12, 13, 14 and a bottom plate 15, includes: fixation parts 21, 31 fixedly attached to upper edge parts 16 of the side plates 11, 12, 13, 14 and fin-shaped pieces 22, 32 extending in the width direction of the side plates 11, 12, 13, 14 at a lower position separated from the fixation parts 21, 31, and coming in contact with inside surfaces A of the side plates 11, 12, 13, 14 at tip end parts 221, 321. The fin-shaped pieces 22 32 are made of flexible material.SELECTED DRAWING: Figure 3COPYRIGHT: (C)2016,JPO&INPIT【課題】観賞魚用水槽の側板に取り付けられ、水槽内の水跳ねを防止する水跳ね防止具を提供する。【解決手段】水跳ね防止具2,3は、四周側板11,12,13,14及び底板15を有する水槽1に取り付けられるものであって、前記側板11,12,13,14の上縁部16に取付固定される固定部21,31と、前記固定部21,31から離間した下方位置で前記側板11,12,13,14の幅方向に延び、先端部221,321において前記側板11,12,13,14の内側面Aに当接するヒレ状片22,32と、を備え、前記ヒレ状片22,32が可撓性を有する素材からなる。【選択図】図3