A fish that can leap into the air with a spring of its tail, and keep itself up by its fins for a time as if flying. Its pectoral fins are developed so as to act like wings. It can fly for hundreds of yards, and is frequently attacked by sea-birds and dolphins (q.v.). It has a bladder that can be inflated to fill the whole cavity of the abdomen ; it has also a membrane that is inflated through the gills. The California flying-fish is said to fly for nearly a quarter of a mile, usually not rising more than four feet. There are several kinds, which are found in tropical seas.