Ok then I will give the rhizome division a try. No it's not the celestial pearl danio (black and red). Finally found a pic of it, here in São Paulo it's called xadrezinho (checkers)
The one I saw was really tiny (1.5-2cm) and it was R$2,70 (US$1.03)
I know that it's commonly used in amazon biotopes
Does anyone have info on this fish (Dicrossus filamentosus)?