Any tank that is at least 5 litres (1 gallon) in size, NO LESS.
Betta
Betta fish are about the only kind of fish that can survive with no filter. They prefer still water or a very gentle current, so as long as you are keeping their water warm and clean (at least 80* F) they will thrive in a one gallon, unfiltered bowl. Change the water at least weekly to keep a one-gallon betta tank clean. Change more often in anything smaller (and it's not recommended to keep them in anything smaller).
None of them, you sick freak. Keep your fish seperate.
BETTA Fish i think
It is a kind of tropical fish.
He Revealed He Is Half Betta Fish.
Crowntail, Veitail, and Halfmoons.
Water
It deppen on your tank size: 2.5g tank: 1 betta or 2 platy or 2 mollies
Betta, goldfish.ex.
fake plants my fish loves them
Probably the king betta because it's the largest and in most cases the larger the fish, the smarter