an air-filled sac, lying above the alimentary canal in bony fishes, that regulates buoyancy at different depths by a variation in the pressure of the air
2.
any air-filled sac, such as one of the bladders of seaweeds
air bladder in American English
a sac with air or gas in it, found in most fishes and in other animals and some plants
: also air cell
Examples of 'air bladder' in a sentence
air bladder
The gills must feed an air bladder, or versatile lungs of some sort.