If you meant to say oxygen, then yes
some fish, like bettas, swim to the top to get air while others use their gills to get air from the water they live in, like goldfish.
They need a tank fish food
Saltwater fish need to drink, but freshwater fish never drink.
For the mission you need to find the fish at creature area to get the fish you need to play bobo fish
ALL fish need filtration.
There are quite a few reasons, but some common ones are that some fish need room to grow, some fish need room to swim around, and some fish need room to claim a proper territory.
fish need air because they won't be able to breath if they didn't have air, and fish need air badly because they spend most time in the water. fish need air as much as we do.
Tropical fish.
Depends on the fish.
Probly depends on WHAT fish it is
Blood parrots are tropical fish, yes they do need heaters.
TheType of fish that you put in the tank and what they need to survive
To get the angel fish, you need to breed unicorn fish and fairy fish together