They are an awesome Amp. that only gets 10". I personally keep a group of 4 good sized ones, they don't seem to mind each other or my Pbass. What do you want to know about them? I have had mine for about a year, 2 are about 9"-10" one is around 7" and the one I call a Female is around 5". I also keep them with a couple of Amp. Amarillo, this is a fish that comes from the same lake as the Xiloensis.