What do piranhas and goldfish have in common?

The common goldfish, the tiny minnows, the fish tank favorite tetra, the famous Electric Eel, the enormous Mekong Giant Catfish that weighs in at nearly 700 pounds, the gnashing-teeth piranha, the well-studied zebrafish – all these fish have something in common. Other than possessing special bone structures that transmit sound waves from the swim bladder to the inner ear that give them hearing abilities on par with or even exceeding those of humans, they are members of Ostariophysi, a superorder of bony fishes including more than 10,300 species in 1,100 genera and 70 families.