I have bred fish in the past, some CARES fish, so endangered. but it got old, quickly.When I tried breeding, it was for the purpose of making a little money. I tried three species and one of them was an endangered type. So my thought process was that I can make money and a positive side effect would be adding to the number of them in circulation. I sold around 400 and that was to hardcore hobbyist that i know had plans for breeding . So it was a win-win. But it took away from my enjoyment of keeping fish, so I stopped.
never for profit, or any money outside of putting fish into an auction sometimes.
but the thoughts of having a fish room, and breeding all kinds of fish started to look like work and not so enjoyable.
so these days I stock lightly, grow plants, enjoy it more.
and talk to folk who keep fish.