Marbled hatchetfish

These peaceful fish live in schools near the surface. When they use their pectoral fins to leap out of the water, their fins produce a humming sound. Such leaps are rarely longer than 1.5 metres, but these fish have been observed "flying" 90 cm above the water. It seems that they leap out of the water to escape their predators. Before taking flight, a hatchetfish may hydroplane for more than 10 metres.