Air-Bladder of Fishes (With Diagram) | Vertebrates | Chordata | Zoology

The air-bladder or swim-bladder is more or less a sac-like structure lying between the alimentary canal and the kidneys. It is a characteristic organ of Osteichthyes (bony fishes). It is a gas-filled pneumatic sac, called air-bladder or swim-bladder. Air-bladder does not occur in elasmobranchs. However, it is found in all Osteichthyes (bony fishes) except a few bottom dwellers (Lophius, Pleuronectes, [...]