Fish have an gas-filled, internal swim bladder, whose buoyancy they regulate to keep from sinking or rising in the water.
Fish tanks were not 'discovered' they were invented.
sink
yes it is
You can float in bodies of water such as lakes, oceans, rivers, and pools. Additionally, some places offer sensory deprivation tanks or float tanks designed for therapeutic floating experiences.
subs have empty tanks in them. this empty tanks are filled with water when the subs need to sink and emptied when the subs need to float.
fish does float on water!
The Roman empire had a very large industry making fish tanks, before that, the Chinese had been raising fish in holding tanks for about a thousand years. Before that, people were probably building fish tanks since before we understood how to make fire.
fish tanks
it is the same as fish tanks
One can buy used fish tanks on AquaBid. On there, you can buy or sell used fish aquariums. Many tanks on there are cheap and afforadable, but make sure you clean it.
they float because they are clever
floating like fish