Help me please!!

[moosh52]

i have 2 goldfish which i have kept together in a tank for around a year, one white and one orange. they were a similar size when i bought them, however a few months ago, the orange fish started to develop a growth on its back near its tail. this has gradually got larger as the weeks have gone on, and after seeking advice from a local aquatics shop, we have monitored the fish and noticed it has grown quite a bit bigger than the white one.
Now the main issue i have, and i'm not sure if this is at all related to the growth (?) is that the orange fish has started to get quite aggressive towards the white one. chasing it around the tank and bashing into it. this has lead to the white fish becoming very subdued, just sitting on the bottom of the tank not really moving with very slow breathing (i mean its gills are only moving every now and again...i'm not up on my terminology!)
This morning, after watching in horror as the white fish was being thrown around the tank by the orange one, i took drastic action and removed the white fish from the tank and placed it in a large glass bowl. I am not sure if this was the correct action to take but i couldn't watch it being attacked any longer. Can someone please advise me on what i should do?? I have become quite attached to my little fish and hate watching them not get on.
Thanks!!!!

 

[FishGeek]

Im not really sure about Goldfish (hopefully someone who is will halp you out soon). But I just wanted to say that you did the right thing by removing the fish that was getting beaten up. What size tank are they in??

 

[angelmom]

Do you know what kind of Goldfish they are? I did some reading there is a type call Ryukin and they can be agressive toward other types of goldfish. I don't know if you got two different kinds or not.

You did the correct thing taking the white one out.

 

[YahooFishKeeper]

i have never seen that in goldies, i have had a few kinds, and i did have a lionhead, and a torpedo together, and they were buds. they would swim together, and look for foor together, and chase knife feeders together... they were always together. maybe they were having territory problems. what size tank are they in, and how big are they?

 

[moosh52]

they are fantails in a tank that's about 12 litres. The aggressive orange fish is about 3/4 inch longer than the white one, but is fatter overall. thanks for your replies!!

 

[UP UP AND GUPPY]

I never heard of this except 1 time I had an Oranda dominate a whole Orandda tank.

 

[Seleya]

A 3 gallon tank (12 liters) is much, much too small for even one goldfish -- your two goldies would require at least a 20 long and more suitably a 30 long at a minumum. How large are they?

It sounds to me like breeding behaviour -- the male will chase the female around and bump her just like you describe. Does the orange fish have breeding tubercules (little white spots) on his gill plates and dorsal fins? Spring has sprung.

Do you have pictures of your fish? Sometimes, ryukins are sold as fantails -- they slowly develop their hump, so you may not know they're ryukins at an early age.