Hi everyone,

Just wondering if someone could help me with this question. We just bought a huuugge new tank for my husband which came with one beautiful (or so we thought) fantail.

We have put him in a tank with our other fish, one black moor, two small gold fish, one other fantail and a larger goldfish while the new tank cycles.

The problem is that he is being really aggressive towards the large gold fish and the fantail - chasing them around continuously and pushing them around the tail. Looking at your video I think that he must be spawning - but the girls don't look to want anything to do with him. (I am just presuming the sex of the goldfish by the way they behave - I don't really know!)

We have gone from a quiet peaceful tank of contented fish, to a seething tank of fishy fantasy!

The question is should we try and separate him so that the girls don't get hurt? Do they do this forever until they lay eggs? Or will he get sick of them? How do we know if the girls are ready to breed?

This is worse than reality tv!!!!!

fishnchips

This is a situation I know well and I have 2 blackmoors that do exactly the same. I've separated them into a 20 gallon and now they're terrorising each other. They have scales missing and slightly torn fins but they just never let up on my other fish It's a seasonal thing - they're quiet during the colder months but now the weather's heating up - so too are they

You can try and make a divider or separate him to a big tub with filtration. How big is the tank they're all in?

Thanks Jen.
We have used your forum before when we first inherited our fish and have been through all the tank logistics. Our tank is too small for the amt of fish we have, however we have managed to keep them healthy with regular water changes and by monitoring the water condition closely - thanks for your advice re those things.

Our main problem now is the way this new fish is acting. One of the females is a plain comet. Can they breed with a fantail? Is your advice that I should just watch them for stress etc and move him out if they look too upset? Does the way that he is acting mean that the others are definately female and they have eggs? Will it be obvious if they have spawned?

So many questions!
thanks for your help