hi! I have a younger bluefin/black damsel for sale. He (not sure of sex) is probably close to 5" long including tail and has gotten the dark blue bottom fins but the body is still pretty light with some clear fins. I had a couple others that were older and they had already started turning very dark. As it matures it will get a dark blue/black color all over. This fish came with another tank purchase and I've enjoyed him but it's time for him to find another home. He's got a cute personality and will come up to the glass to check you out but is quite territorial and doesn't appreciate you sticking your hand into HIS tank! lol I haven't noticed him picking at any of my corals up to this point. I've had him since December. When I got him he was very light blue with all clear fins if that might tell you his age. http://m.liveaquaria.com/product/prod_display.cfm?c=15+28+765&pcatid=765
