I bought 3 chromis, and a tiny scooter blenny sunday ( 4 days ago) put them in my qt tank running .25 copper at the moment. they looked good, except i spectinf them in the bag before i vought them the one had a small spot on it.. but I've seen that happen when you catch fish w a net. it is looking way worate and bigger, plus another one has an odd dark coloring on both sides down one the bottom edge of it. of the three, one is Def bigger.. that one has no marks. chromis are not aggressive, except now that the one looks bad it is getting g chased a bit