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How do grunts make sounds?

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Bluefin tuna swimming underwater in a group, with silvery bodies and streamlined shapes, near Japan. — perciform Bluefin tuna (*Thunnus thynnus orientalis*) in the waters near Japan.

Grunts, which belong to the order Perciformes, produce their characteristic piglike sounds by grinding their upper and lower pharyngeal (throat) teeth together. Once these sounds are generated, they are amplified by the fish's swim bladder, which acts as a resonator.12