Or. Because the fancy-fishes that won the Once in 10 Million Years lottery got out of that dangerous place as soon as they could and left the fish to it.
True, but they also cannot live outside water and most people do put them under fish, even though it isn't technically correct.
Actually not all fish breathe underwater, whales for example need to come up for air and so do dolphins. It's a good question.
Because all the fish-type ancestors (apart from a few with randomly useful genes) who tried something different died.
Cause they'd die on land? They have gills which filter oxygen out of water so thats the only way they can breath.
Why do humans live on land? ¬_¬
Humans breathe AIR to survive, Fish "breathe" WATER to survive.
They have gills.. and would die if they stay out of the water for like 5 mins.. I believe.
cus their fish, its where they were born
but they are not fish, they are mammals