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.
Fish dont usually swim to the surface of the water unless food is present although if a fish is floating on the surface it is most likely dead. Hope this helps :)
Water is one part hydrogen and two parts oxygen. The fish extract the oxygen from the water
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
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.
They depend on the water to provide food for them to survive.
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.
The gravity around the earth holds the water in place
Lions stay cool by dipping their feet in a near by river or just some water.
Mosquitoes and other small insects can stay afloat on water because water exhibits a property called "surface tension", where a thin film "seems" to cover the water surface. This has something to do with intermolecular forces of attraction.