one of my fish is being bullied

Question
Hi,I have a 30 litre Bi-Orb, and in it I have a pearl scale goldfish which I have had for over a year and another much smaller fancy goldfish. a few days ago I introduced two canary goldfish. They are both much smaller than the pearlscale but constantly chase him around the bowl attacking him. and since their arrival the pearlscale , although is still active and feeding has turned almost totally black, all its fins are black and it sort of looks like someone has tipped soot on him cause the top half of his body is also black, the small fancy goldfish is still ok though, is there any way i can stop the bullying, it is horrible to watch!

Answer
Hi Allison,
Canary goldfish aren't really the best tankmates for fancy goldfish like a Pearscale. Canary goldfish are much faster and bolder and can have a tendency to be aggressive. They are actually best suited to outdoor garden ponds because they can grow to larger sizes than fancy goldfish.

There probably isn't much of a chance of them getting along very well because of the small size of the tank and the temperaments of the goldfish. Actually the bio-orb may not be able to hold the Pearscale and Fancy goldfish longterm.

The black fins and black coloration on the pearscale may just be natural coloration. Goldfish are very well-known for changing color as they age. But it could also be ammonia burn so be very careful about that. The danger of ammonia burn is very high with goldfish being in such a small tank. Hopefully the tank is cycled and there is no ammonia but it wouldn't hurt to test your water just in case.

The best thing in your situation would be to remove the bullying goldfish and just have the Pearscale and fancy goldfish in there, they will likely have to be upgraded to larger living quarters as they get older and grow larger.

Sorry about the bad news, I wish you the best though!
Karen~