Urgent Help Please - Fish Behaviour

[Hale9]

Hi,

I'll try and cut a long story short.

We have two fancies. They are approximately 3-4 years old and have been together all this time.

We've recently had to take them out of their tank and keep them in a large container whilst some maintenance was carried out to their tank. They were in the container for approximately two weeks.

The tank is cycled, and is 30 gallons.

Since we've put them back into the tank one of the fish has been chasing the other constantly. I've been reading up on breeding and can find no significant information, but it has come to a point where the 'chasing' fish has caused the other fish to lay, with their head pointing downwards, behind the filter. The fish was in this position when I woke up, and is still there now an hour or so later. I don't know how long it was in this position whilst I was asleep.

Often the 'chasing' fish will go away for awhile, swim around the tank, but then come back and start bothering the other fish whilst it lays still behind the filter.

Is this very extreme breeding, or have we somehow caused a new fight of dominance by having them out of their tank for 2 weeks? They have known each other so many years it is sad to see.

Please note that the fish is not dead, as their eyes are still moving. I have no idea how long a goldfish can last without getting to the top for air. A quick search returns that the water contains enough oxygen for a day or two at a push.

Please help. Should I let nature run its cause, or do we need to separate?

Thanks.

 

[KittyKat]

Please add some more set-up and water information: http/www.fishforums.net/index.php?/topic/2330-please-read-before-posting-to-emergency-section/

Did you run the filter on the container or the tank, for those two weeks?

 

[Hale9]

Hi,

I am at work now, but from the top of my head:

tank size: 30G
pH: 7.2 / 7.6
ammonia: 0.25 (same as from tap)
nitrite: 0
nitrate: 0
kH: n/a
gH: n/a
tank temp: room temp.

Water changes: weekly, around 30%

Chemicals: We had 'Prime' to the water due to the ammonia levels in our tap.

We were not running the filter in the container, but had a small sponge filter and a separate air stone to provide oxygen. We were making water changes daily, and were added both prime and a tap conditioner (I forget the name). We knew this wasn't ideal, but didn't have much choice as the tank sprung a leak. Whilst in the container we didn't notice any of this behaviour.

Thanks for your help,
Sam

 

[Hale9]

Also, a quick update, before I left for work I decided to move the filter up slightly so there wasn't enough room to get 'stuck'. The 'resting' fish quickly swam off and was lively, so I'm not sure it has any health problems, at least not any obvious ones, but the chasing continued and pinned the 'resting' fish into a corner, rather than behind the filter. I looked at the 'chasing' fish, and he does seem to have white markings on his face that I haven't noticed before. Perhaps he is just a fairly aggressive breeder?

 

[KittyKat]

Is this very extreme breeding, or have we somehow caused a new fight of dominance by having them out of their tank for 2 weeks? They have known each other so many years it is sad to see.

From what I know of goldfish (I used to keep them until about 12 years ago), this is normal breeding aggression, if it is caused by breeding. This is another good reason to keep 6+ of the species together, because aggression will be spread that way.

I have no idea how long a goldfish can last without getting to the top for air. A quick search returns that the water contains enough oxygen for a day or two at a push.

As far as I am aware, goldfish do not breath from the atmosphere like labyrinth fish and Corydoras. They get all their oxygen from what is already in the water. They should not be gasping at the surface unless there is not enough surface movement.

tank size: 30G

This is quite small, for goldfish: the female (if it is breeding aggression) would not have anywhere to get away to..

ammonia: 0.25 (same as from tap)

I'm surprised your filter has not come to be able to deal with this by now..

nitrate: 0

This is very unusual, how do you get it this low?

We were not running the filter in the container, but had a small sponge filter and a separate air stone to provide oxygen. We were making water changes daily, and were added both prime and a tap conditioner (I forget the name). We knew this wasn't ideal, but didn't have much choice as the tank sprung a leak. Whilst in the container we didn't notice any of this behaviour.

Two weeks without ammonia would have killed off most of the bacteria in your main tank.. double check ammonia and nitrite with a different liquid test kit (for example, get the LFS to test it, and write down all the readings).

Perhaps he is just a fairly aggressive breeder?

I would add a divider into the tank, or separate the fish altogether.. the "male" can stress the "female" to death.