TO USE: Cradle fish in hand in a horizontal position with gentle but steady pressure. Fill pump with water, then empty bulb so only the straw contains water. With bulb collapsed slide the tube gentle into the fish. Squirt a few drops of water into the fish's stomach then release the pressure on the bulb. The contents of the fish's stomach will be drawn into the straw. With smaller fish use less suction. Release fish, squeeze contents of pump into palm or vial to examine.