I have a single p. crabro in a standard 75gal tank with: 6 l. caeruleus, 6 m. callainos, and 4 p. acei, all but 2 labs are adults. I bought it at about an inch from nose to tail, and two months later it's around 3 to 3 1/2 inches. My question is, at what age will it reach its adult coloration. I know females retain the yellow/brown barring, and males turn a dark blueish color with darker barring. I'm just curious if I have a male or female. Either way, its quite healthy and active (hence the crappy pics), a gets along well with the other fish, which I know can change when it reaches sexual maturity. Anyways, sorry to ramble, and on to the pics. Thanks everybody.