Your fish may be sinking due to a swim bladder disorder, which affects its ability to control buoyancy. This can be caused by overfeeding, poor water quality, or a bacterial infection. Consulting a veterinarian or fish expert can help diagnose and treat the issue.
The swim bladder
Fish have an gas-filled, internal swim bladder, whose buoyancy they regulate to keep from sinking or rising in the water.
Fish do not normally "float around" they swim. If your fish is floating/sinking then it is probably dead.
When worn properly a life jacket can keep you from sinking even if you are unconscious.
i don't think fish sleep (the plural of fish is fish.)
Shark
To keep from sinking and capture more light.
Walk on hard ground. There is no way to keep them from sinking in soft or grass areas. You have to watch where you step.
There could be several reasons why your fish is sinking to the bottom of the tank. It could be due to a swim bladder disorder, overfeeding, water quality issues, or a health problem. It is important to monitor your fish closely and consult with a veterinarian or a fish expert for proper diagnosis and treatment.
Make sure there are no holes
To keep from sinking and to capture more light
Fish body is of boat shape to balance itself in the water nature have given swimming bladders for fish.