Fish gather in the corner of the tank...

[jaydawg53]

Hi guys; I have a 10g tank at the house with a guorami, some tetras, and some other kinds of small fish. (I'm sorry, I just don't remember for sure). ANyway, ther eare 7 fish and a snail. The tank has been established for a few months, but suddenly, all of the fish have started huddling together in one corner of the tank. If I walk up to the tank, they swim around everywhere, since they expect food whenever I approach the tank. When I feed them, they all eat just fine.

I guess it just looks so strange, and I've never noticed it until this week. Is there a bad reason they would do this, or is it just strange behavior that I shouldn't worry about?

Thanks!!

 

[An t-iasg]

Are all the fish huddled together, or just some of them? It might be that one fish is dominant and is not allowing the rest of the fish to come out into the open parts of the tank. Do you see any other signs of aggression, like nipping? Do some of the fish look "faded"? Color loss can be a sign of stress.

Can you post pictures, so the fish you aren't sure of can be identified?

Sometimes, juvenile fish are fine together, like yours were fine for a few months. When they start to reach maturity, they want their own territories, and a 10 gallon tank doesn't leave much room for 7 fish to have their own territories.

 

[itafx]

Another thing I've experienced is having fish go to one part of the tank when conditions become unfavorable. Like if the temp is too low, they will huddle close to the heater, or if you put too much of a chemical and they huddle the farthest away from the concentration in the water.

 

[QTOFFER]

...or if the water isn't getting enough oxygen. Are the fish gasping at all? Is the filter agitating the surface? Is the temperature too high?

I would continue investigating and rule out the possibility that something is wrong.

 

[jaydawg53]

well, I keep it at a steady 80 degrees, and they're not gathering at the heater. The nitrite level is fine, and the PH is good, but those are the only two test kits I have... Also, I did a 30% PWC today, but they're still hudding... sometimes. Other times, they're active as usual. I'll keep an eye on the water specs and let you know if anything is out of whack...

oh, and they're not gasping, and the filter is rippling the same as usual.