I think 6" YP would be sexually mature, have heard stories of 4" YP pulling spawn in tanks. I think both Shorty and James could be pulling spawns - woo hoo!
I have had yearling five inch fish produce eggs and males ready for action at that age too. I will also tell you that small pieces are not necessarily from small fish. One of my big females this year in the cage pushed some eggs out in short segments.
Cecil I have moved 13 SMB from 13-16" to the repro pond. Might do two more and call it good.
Did any of them look like they were packed with eggs?