Swim Bladder

Real World Example

Imagine trying to maintain the perfect height while riding an elevator that constantly shifts up and down. Just as you use the elevator buttons to control your floor level, bony fishes use their swim bladder to control their depth in the water. The swim bladder acts like the elevator's buttons, allowing the fish to add or release gas to rise or sink, maintaining their desired position in the water just as you would select your desired floor in a building.