To be honest im sure they would have bred at a much younger age than when i bred them,they were my first rays second time around if that makes sense,i had them mixed in with all types of fish,more of a community situation really,i wasnt feeding heavily or changing water as regularly as i do now.Since keeping them on their own in what can only be considered as a minimum sized aquarium(6x2x2) they have bred repeatedly,though they are having a natural rest period just now.
I would say they were the size they are now when they bred,they have had all their pups in the last 2 years.