Translations:Adventist Youth Honors Answer Book/Nature/Fishes/36/en
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i. Swim bladder
The gas bladder, or swim bladder, is an internal organ that contributes to the ability of a fish to control its buoyancy, and thus to stay at the current water depth, ascend, or descend without having to waste energy in swimming. It is often absent in fast swimming fishes such as the Tuna and Mackerel families.
