Yesterday I purchased 4 severums. They were listed as turquoise severums at the LFS and 2 of them are black with white caudal fins and white tips on their dorsal and anal fins. Anyway, they are about 2-2.5" not counting the tail fins. They are currently in quarantine and so far so good. Anyway, how big or how old are they before they begin to pair off. I hope I'll end up with 2 pairs - that would be nice - although I doubt that will happen!