A tool for releasing excess air from the swim bladder of a fish. The present invention includes a puncturer situated in a housing and a push rod which extends out of the housing for pushing the puncturer out of the housing and into the swim bladder of the fish. When the tool is employed, the excess air passes through the puncturer into the housing and then out vents located in the side wall of the housing. The puncturer is spring biased to remain in the covered position until the user applies an external force to the push rod to expose the puncturer.