If you talking about the Japanese fighting fish, they don't have gills so they breath like us with lungs.
If not they are probly hungry. just feed them more.
A seal must stay near the water
I don't think there are any fishes that cannot stay in water.
An egg will float in salt water because the salt makes it denser and allows the egg to stay near the surface. But in regular water it will sink straight to the bottom.
Oceans are seawater throughout, not only on the surface.
croocidiles can stay on land on a period of time but fishes cant
They depend on the water to provide food for them to survive.
A card can stay on a full glass of water because of surface tension. The cohesive forces between water molecules create a thin film on the surface that can support the weight of the card.
Being able to use the turbulence in the water to help them stay afloat is one adaptation that the plankton has to keep themselves afloat. They also use structures near the surface of the water to help them.
This is because they need Oxygen for respiration
As water warms, it expands. Having expanded, it is lighter, and floats at the surface- where it may be warmed more by the sunlight.
Lions stay cool by dipping their feet in a near by river or just some water.
The gravity around the earth holds the water in place