Tag Archives: Fishes

What are Swim Bladders?

Swim Bladder, also called air bladder, is an expandable gas-filled sac that helps many bony fishes to control their buoyancy in order to stay at their current water depth without having to waste energy in swimming. A swim bladder is similar to a lung in structure and function in some primitive fishes, but it is not a lung because most cases its primary role is not respiration. Continue reading What are Swim Bladders?