A tool for saving the lives of captured fish that are swollen by expanded gases when brought to the surface includes an elongate hollow tube of rigid construction having a sharp cutting edge formed in a distal free end of the tube. A user grasps a proximal end of the tube and punctures a fish at a predetermined location in its body with the sharp cutting edge to allow gases to flow out of the body of the fish until the body returns to a substantially unswollen condition. The fish is conventionally resuscitated prior to release after the gases have been vented. The tube folds into a handle for storage when not in use.