Dillema and bullying

[Stefernini]

My new little guy, a 2.5 inch lion head, has been in quarantine for a week and a half and last night I decided he was okay to throw in the big tank with the big boys. I put him in while the others were distracted eating, watched for a bit, and then went about my business.

When I went back to turn the lights out for the night, my two big boys, Gus and Fred, were chasing poor little Dickie all over the place and kept pushing him and pinning him in the corners. I startled them and they swam away and the poor little dude sank immediately to the gravel, pinned his pectoral fins and just laid there breathing hard. I put him back in quarantine, but it's just a little 10 gallon.

How long can I keep him in the 10, and how can I prevent my bullies from doing this again?

These two like to do this to Derpington as well, but not to this extreme. She's bigger than both of them, however, and it doesn't seem to stress her out. Although I'm sure her brain is fried a bit...

 

[jlk]

What size tank? How big/what type goldfish are in there presently? Aggressive behavior in goldfish is typically caused by too many fish in too small of a space. If was a single fish, I would put it off to dominant behavior and could make some suggestions on dealing with this. Two fish displaying this behavior, however, is more indicative of a tank issue. Some more info will help!

 

[Stefernini]

My apologies, it's a 55 with three big fancies and the little guy once I figure out what's going on. You can read their story on this thread http://www.aquariumadvice.com/forums/f135/goldfish-rescue-262206.html

Ammo - 0
No2 - 0
No3 - <20
pH - 7.8

 

[jlk]

Ok, I remember! The moor with ammonia burns (who looks great now, btw!). Ok, I hate to say this, but they don't want another tankmate. The tankmate you chose also has a much harder time swimming than the other three. My only suggestion would be to add LOTS of décor (nothing sharp, enclosed or jagged though!) such as real or silk plants. You then can try to reintroduce the new fish. If this still doesn't work, unfortunately, there is not much else you can do other than consider a tank divider but I honestly would not add another fish to the tank. The larger goldies have the capacity to bully the new, tiny slow baby to death if they want. Good luck!

 

[Stefernini]

Hmmm. Well, I added some pots and some plants and put him back in. He has several places to hide now and is using them, so we'll see how it goes. I'm really hoping it will work. So far so good.

These are my first goldfish and I'm learning on the go. I had no idea they could be territorial, do they have rank too?

 

[Stefernini]

Well, apparently the little one just needed some spots to hide. I put small terracotta pots in, broke down and bought some fake plants and now everything is just fine, in fact I caught him chasing the gold one yesterday. Pay back!

 

[jlk]

Glad he is settling in! Keep an eye on everyone for a bit to make sure everyone is getting along.

I would not say goldfish have 'rank' but they definitely have different personalities like people. Some are not necessarily pleasant or social ones either. There can be a bit of territory issues on occasions such as yours- your guys were together for a long time with no one else and they weren't thrilled with new company. Changing their décor helped in this case.

More often than not, there's space issues or water quality issues which both make for unhappy fish. Lastly, you will see dominant behavior issues by sexually mature male(s). They will bully and abuse females and other less aggressive males to exhaustion, injury and sometimes even demise.