For the record my tang is only about 1 1/2 inches long write know and will be heading into the 75gal. once it cycles. The mandrin has been in there for about 5-6 months now and is not skinny at all. Steve showed me and article on mandrins and signs of it being to thin. I also feed him a few brine shrimp a daily and mostly eat doesn't eat any more then one so he must be getting enough food. I doubt he would survive this long with out food. He is very healthy and scoots along the bottom all around the tank. I see him on liverock all the time eating all the time.