I have a openning or two in my 60 gallon (just moved a fish from there to my 180) and am stuck trying to figure out what if anything I can add. Ideally I would like to add 2 fish if I could find something that would be compatible with the current residents. Current stock list is a large Maroon Yellow Stripe Clown, Coral Beauty Angel, Blue Damsel, large Black Long Spine Urchin, Blood Red Fire Shrimp, Cleaner Shrimp and CUC. I would need a somewhat semi-aggressive fish (or fishes) that could stand up to that group as they have all been in the tank for about a year and a half. And before anyone suggests it "I am not gonna get rid of the Damsel". The damsel actually is chased by the angel and clown. If I can't come up with any suitable fish I was thinking about a Snowflake Eel, but wasn't sure if he would be OK with the Long Spine Urchin considering the eels poor vision I didn't want him running into the urchin and getting poked. Any suggestions???? Thanks.