About

The puffer fish, also called blowfish, swellfish, globefish, balloonfish are fish making up the family Tetraodontidae, within the order Tetraodontiformes.

The pufferfish’s unique and distinctive natural defenses are necessary due to their particular form of locomotion. Puffer fish use a combination of pectoral, dorsal, anal, and caudal fins for propulsion that make them highly maneuverable but very slow, and therefore comparatively easy targets for predators. As a defense mechanism, puffer fish have the ability to inflate rapidly, filling their extremely elastic stomachs with water (or air when outside the water) until they are almost spherica in shape. Thus, a hungry predator stalking the puffer fish may suddenly find itself facing what seems to be a much larger fish and pause, giving the puffer fish an opportunity to retreat to safety.

Wikipedia on puffer fish