swim bladder

Found in Anh - Anh (Wordnet)

Definition Noun : * An air-filled sac near the spinal column in many fishes that helps maintain buoyancy : A gas-filled internal organ found in most bony fish. By adjusting the volume of gas within this sac, a fish can control its depth in the water without having to swim constantly. Usage The term "swim bladder" is a specific anatomical term. It is used in biological, zoological, and ichthyolo...