i have a five pygo mixed shoal. two of my reds (6 and 5.5 inches) are really darkening and always chasing each other and doing a lot of circling and waggin between themselves and none of the other fish. are they typically sexually mature at that size and is this a possible precursor to spawning? i just want to know if i MAY have a potentially breeding pair that should be seperated since i have no p breeding experience. thanks.