I've got a 31,7 gallon tank in which about 35 fishes live. For cleaner fishes it is: 2 Antenna catfish (black and brown) and since almost 4 weeks now also 5 armored catfish (others are all non cleaner fish).
While 1 antenna catfish was lazy to start with the other (black) was always very very (hyper)active. Moving along the glass window constantly and cleaning / eating. Also he was within minutes on a fodder tablet when it was thrown in.
A good week ago his behaviour changed almost over night. He is almost constantly only at 1 location and ignores the fodder tablets completely. He still changes places on the glass, but not constantly like before but more like 1-3 times per day in total.
Other things I noticed
- The fish is under 1 year in age. He is in the tank since 2-3 months.
- If a fish gets too near and tries to bite him...he reacts as aggresively as in the past
- When he moves a bit along the glass I do not notice any lack of strength with him holding onto the glass (thus as strong as always)
- There is nothing on his body that seems like it changed (no inflated stomach or visible fungus, ...)
- There was a problem with the filter 4 weeks ago which quite a few fishes their lives (I overlooked that I had to remove the filter compltely to see if it is too dirty to work any longer....lesson learnt even if it was a very sad one back then). Aside from that and one homicidal fish in the tank there is nothing that seems to have changed or is out of order.
- Fishes are fed with the tablets and flake lining (same as since months).
As I know from past experiences a sudden behvaioural change is almost never a good sign I'm quite a bit distressed there, but at a loos as to what to do (or if I'm overreacting and that change is normal).
So the question is: Is there anything I can do there or look out for?
