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A gas-filled structure in many fishes that functions to maintain buoyancy and, in some species, to aid in respiration or to produce sound. Also called air bladder, gas bladder.
(Zoology) ichthyol another name for air bladder1
1. a vesicle or sac containing air.
2. an air-filled sac at the top of the body cavity in bony fishes, serving in most to regulate hydrostatic pressure. Also called swim bladder.
See air bladder.