Luciosoma bleekeri (Chinese: 布氏梭大口魚, Thai: ปลาซิวอ้าว) is a species of small cyprinid fish found in Southeast Asia from the Mae Klong River to the Mekong. It lives mainly in rivers, moving into flooded forests and fields during the floods and back into the river as the floods recede. It usually swims close to the surface in schools of many individuals.It is one of the most abundant of the different types of minnow-sized fishes known as (Pla sio) in Thailand.