Anyone have experience with an aggressive goldfish?

[Nness]

I was wondering if anyone has ever had a goldfish who is aggressive to others and if having tank mates works out? I currently have a young black Moor who belonged to my friend who had a 150litre tank with one other fish in it, but he kept attacking him and harassing him so she just couldnt keep them together anymore and now I have him. I'd love to upgrade his tank when he's a bit bigger for something that can house more goldfish, maybe something around 200-300 litres but I'm worried about him attacking future tank mates. Would it be best to keep him alone or could it work? The fish he was attacking was a male too so i worry it'd be even worse with a female

 

[PlasticGalaxy]

I can't remember who it was but someone's black moor almost ate their cory catfish. Not sure if it was due to aggression or general goldfish stupidity.

On a whole, goldfish aren't inherently aggressive, but I believe they can be if they don't have enough room. Never had goldfish, so I've got no personal experience, though.

 

[Nness]

I can't remember who it was but someone's black moor almost ate their cory catfish. Not sure if it was due to aggression or general goldfish stupidity.

On a whole, goldfish aren't inherently aggressive, but I believe they can be if they don't have enough room. Never had goldfish, so I've got no personal experience, though.

Omg good thing they caught it on time before it was eaten!! And yes that'd definitely make sense but the tank was considered enough for 2, maybe he just likes a little extra space ? so odd! He thinks he's the boss but he's only tiny right now!

 

[PlasticGalaxy]

He thinks he's the boss but he's only tiny right now!

Ahh tell me about it. My red tail shark is such a meany, when he's well aware that I have shrimp in that tank bigger than him.

 

[QiQi]

My ex landlord had a common goldfish and a weather loach (pretty much an inch each fish) in a 28L and the goldfish was picking on the loach till it died. I took her with me when I moved out and upgraded to a 70L (the best I could do at the time) and I kept her alone, she grew to about 7inches till I finally found a proper home for her. When we acclimated her and put her in the pond she seemed fine with the other fish and I get regular updates, she is doing great, no aggression and she spawned, she is probably 8 years old now.
Maybe she isn't aggressive since there is enough space for everyone in the pond.

 

[Colin_T]

pictures and video of the fish "attacking" others?
.
it's probably just a male trying to breed with the females.

 

[Nness]

pictures and video of the fish "attacking" others?
.
it's probably just a male trying to breed with the females.

I'll have to ask my friend for them, he was chasing a much older male constantly! He's only jus started developing breeding tubercules, would they be showing that behaviour before having any?

 

[Colin_T]

He's only jus started developing breeding tubercules, would they be showing that behaviour before having any?

yep

 

[Guest14017]

Have had several aggressive goldies. ALL black moors. Picked at others. Stole food etc. And it had nothing to do with gender. Black moors just tend to be snappy in my experience.