Goldfish are very resilient. Let her be and she may come around. Don't leave the tank lights on a lot and don't fool around with the tank, it will just stress her out more. Be careful if you medicate her since some may be strong enough to send her into shock. Something mild like stress coat would do well.
I've had a goldfish with missing scales, and even though they never grew back the fish was fine.
As to the aggressor turn it in to a LFS or petsmart or something like that. Is it all orange or does it have stripes?
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55gal,216 watt Tek T5, 45#LR, 45#LS, 3 maxi-jet 900's on a natural wavemaker timer,phosban reactor, 5 gal fuge (built out of standard 10 gallon tank) with chaeto and feather caulerpa, sealife systems protein skimmer, wet/dry, 3 blue/green chromi, 1 skunk cleaner shrimp, 1 coral beauty,1 scopas tang, 2 false percs, 5 mexican turbo snails, assorted dwarf blue leg hermits, astrea snails, and nerite snails |