Hey Rob if it means anything, my supposed brevis does in fact have a black adipose fin with a grey edge. He's also very stubborn and hasn't eaten any pellets yet. He does bite them so I'm hoping he breaks soon. And thanks for the great write up and info!
It does to me.
How big is he now? Yours looks rather like mine color wise and head wise, but I think yours is much more well-fed. Yours seems to aldeady be developing that big humpback as the big guy that I posted in your thread.
I'm really looking forward to watching your guy grow up next to mine. I'm really curious to know when they develop their signature dusky color as they grow. I suspect it'll be around a foot long.
Edit- For anyone who's not familiar with it, this is the picture I'm referring to:











