I've heard 3 years. I had petricola and mine did not get serious for five years, but the lucipinnis are more different than I thought apparently. Larger spawns and better survival rate if left to themselves in a tank.
Mine were about 2 years old and 3" when they started to show breeding behavior (chasing and knotting themselves). I didn't cultivate any fry, so this may well have been "dry run" behavior, it looked legitimate though. HTH!
What age/size are you getting em at? As said they are slow to grow and mature (home bred grew at max of about 1" a year for me but only kept a couple from home breeding to breeding themselves (for me a full 4 years but kept in communitty tanks)) but then breeding groups can be bought but you are looking for guys at about 3"+ to breed well quickly.
I guess thats why 1" guys are so cheap Ã‚Â£5-20 here and 3"+ young adults cost about Ã‚Â£20-60 each depending on where you get em.
I guess its can be quicker using large scale breeding and rearing when you know the ins and outs of getting em large quickly.
Get em at 1" and your looking to grow em on for at least 2 years I think.