I have a behavior issue for which I could use clarification from all of those goldfish enthusiasts out there! I have a 60 gallon planted tank with three fancies in it ( One oranda(male, I think), one fantail (male for sure) and one panda moor with a cataract (female for sure) The Moor and the fantail are both 5 years old. The oranda is a teenager ( I am estimating about 8-9 months.) The problem is this. The oranda is very aggressive with the older fish. As a result, the moor turns over on her back and goes "flippy fish" every time I put her in with the oranda. When I remove her to a hospital tank, she is fine, swims completely upright, and acts normal. My guess is that the teenager is exhibiting spawning behavior, and the moor has had about enough of it. It is also possible that she feeds more efficiently upside down and is more comfortable that way when she has to compete for food. Should I remove the oranda? (I can switch out fish. I have another 60 gallon with a different female, male ratio, but that would give me two aggressive males in a 60 gallon with a red female telescope.) I am reluctant to post this inquiry, with trepidation that I will get a response telling me that 20 gallons/fancy is inadequate space. While the issue may be territorial, there were no problems before the introduction of the blue oranda. Thanks in advance for any suggestions.