I've got new tank 300l and yesterday introduces a group of new fish there 7 of which are red zebras. There had to be two males and 5 females but looks like one of "females" is actually a male because it has bluish fins. Anyway, all fish is active in tank and they look happy, but this one male (whom I purchased as female). He has chosen one cave in the tank and spends most of his time in there. He didnt loos appetite and doesnt look weak, his cave has quite strong current and air bubbles going through that cave. The things that I'm worried about are
1. he sits in one spot most of the time while other ish is playing and chasing each other.
2. his breath is a bit too frequent (maybe he catches those air bubbles that goes through his cave, or...)
Can anyone suggest what is wrong?