When handled, it gulps air and inflates itself into a floating impregnable ball, bristling with little spines. Then bobbing around upside down, using its tail as a rudder, it frantically spits out the air until it can overcome its buoyancy. The boxfish’s black and yellow stripes give the aquarium color, and their heavy, bone-crushing jaws can be used to demonstrate their specialized snail and crab feeding mechanism. Size: 8-16 cm.