I have fish in an aquarium
dans in French means - in or inside
'...est dans..." means "...is in..." in French
'dans' eans 'in'
'dans' eans 'in'
dans une ville means 'in a town' in French.
dans un village means 'in a village' in French.
'dans la faut gouter' makes no sense in French.
Dans le fauteuil means 'in the armchair'.
Dans ma famille means "in my family" in French.
If you mean the BETTA, then it is "poissons de combat japonais". But we really refer to them as BETTAS in both English and French.
Dans ton pays means "in your country" in French.
It means She is in