Yes. If they don't, they will suffocate and die, like if you were locked in an airtight room.
Increases the fish's volume by filling the swim bladder with oxygen.
fishs eddy
Stagnant ponds and rice patties in the Vietnam area. They breathe air because the water doesn't have any oxygen in it.
NO
deers or fishs
The Indian & Pacific Oceans .
sharks and more
bass, bream,
chalk goby
Gills
His fish are named Brock and Swimmy
what do fish eat