No they cant really control gravity anyway...
fish maintain buoyancy usind a organ near there gills wich fills with oxygen and keeps the fish afloat
as they fill or release air it will control where you are in the water. It is a lot harder for a fish, the fish have to get the air from their blood stream because they do not have lungs. Taking in air is harder because it is via their blood and they cannot release the air as fast as buoyancy compensator vests. Include all of this information and you should do fine. :3 your welcome btw
stress?
A fish has neutral buoyancy to maintain its position in the water column without sinking or floating to the surface. This allows the fish to conserve energy by not having to constantly swim to stay at a certain depth. By adjusting its swim bladder or other internal gas pockets, a fish can achieve neutral buoyancy.
The fish gains buoyancy and is able to rise in elevation .
swim bladder
they have an organ called a swim bladder. it is a buoyancy device
Fish have an gas-filled, internal swim bladder, whose buoyancy they regulate to keep from sinking or rising in the water.
They have organs called swim bladders, which balance the fish and keep them from floating.
Bony fish have a swim bladder that helps them regulate their buoyancy and control their depth in the water. By adjusting the amount of air in the swim bladder, bony fish can increase or decrease their buoyancy, allowing them to float or sink as needed.
The similarity lies in their use - the control of buoyancy.
The Osteichthyes is evolved from lungs of early bony fish. The fish have many types of evolved.