Aggressive Behaviour

[RoLo]

So about 3-4 days ago I really started noticing that one of my fishes seem to be very aggressive. I have 3 Pearl Danio's, and 1 of my 3 seems to be acting very aggressively towards the other 2. For example, what always happens is he goes back and forth, side to side, and whenever another 1 of the 2 catch his eyes, he ALWAYS lunges at them full force!! And I notice that the other 2 seems scared as they aren't swimming around as much. Is this aggressive behaviour? What qualifies as aggressive behaviour among fish? And if so, what can I do about it? Is it a bad thing? Any help is much appreciated. Thank you.

 

[KISSfn]

Unfortunately Danios are schooling fish that prefer to be in groups of at least 6 and the more the better. They are a very active species that require minimum tank dimensions of 24" X 15" X 12". Sorry.

 

[RoLo]

So what should I do?

 

[gdoggy1678]

^ Although you may like them i would recommend that you take them back to your lfs and find something that is suitable for a 10 gallon tank. Danios are recommended to be in a 3 to 4 foot tank. How long have you had the fish and tank set up for?

 

[TomShootsPhoto]

That is a quite aggressive behavior. The other 2 fish aren't swimming because of the stress and being terrorized. If they get bigger, they won't have much swimming space, they grown to around 3 inches.

I agree with gdoggy1678, take them back to to store- or - get a bigger tank.

 

[RoLo]

^ Although you may like them i would recommend that you take them back to your lfs and find something that is suitable for a 10 gallon tank. Danios are recommended to be in a 3 to 4 foot tank. How long have you had the fish and tank set up for?

It is going to make 3 weeks that I have had the tank this coming Tuesday, and I have had the fish for about 2 and a half weeks. I told the person at the store I had a 10 gallon, and he didn't say anything negative about it, but I was told that they are a great starter fish and beneficial for the break in period of my tank. I am also pretty sure I won't be able to return fish...should I be? And if so, what is a good type of fish to get instead?

 

[KISSfn]

The person at the store didn't say anything negative because he just wanted to make a sale and probably doesn't know anything about fish. No fish is a great starter fish for the break in period of your tank as they will be exposed to toxic levels of ammonia and nitrites and die. Talk to the store manager and demand they take the fish back. Then without fish you can either do a fishless cycle or get some mature filter media from a friend or if you live in the U.S. you can buy mature filter media.

 

[RoLo]

Well the reason I have the fish already is because I went with fish in cycle as opposed to the fishless cycle, and I will try calling, but I highly doubt they'll take them back, especially after it's almost been 3 weeks.

 

[RoLo]

Although, I noticed that yesterday, and now today, they are not acting aggressive at all, they're back to how they were when I first got them. Hmmm...weird!

 

[Prime Ordeal]

Although, I noticed that yesterday, and now today, they are not acting aggressive at all, they're back to how they were when I first got them. Hmmm...weird!

Have you been making regular water changes to keep the toxins, i.e. ammonia and nitrite, down? They need to be kept below 0.25 at all times. If you haven't, and given that you have too few in a too small of a tank, then it's no wonder they're a bit crabby!

 

[RoLo]

Although, I noticed that yesterday, and now today, they are not acting aggressive at all, they're back to how they were when I first got them. Hmmm...weird!

Have you been making regular water changes to keep the toxins, i.e. ammonia and nitrite, down? They need to be kept below 0.25 at all times. If you haven't, and given that you have too few in a too small of a tank, then it's no wonder they're a bit crabby!

I been changing my water twice a week.

 

[KISSfn]

I changed my water twice a day when I was stuck in a fish in cycle. What are your Ammonia, Nitrite and Nitrate readings?