Serrasalmus species?

Last night I feed my Baby Serrasalmus, like usual he ate everything and was doing fine chasing the plecos around and everything. This morning I go down there and hes upside down swimming laying on the gravel and can't get his balance.

So hes was almost dead, I do a 50 % water change put some meds in there and grab my net and stert to swim him around in the water for 5 minutes and I let him go and he goes straight to the bottom upside down again. I do it again for 5 minutes let him go and he starts to swim with his balance more straight, I had to leave for work so 9 hours later I come home go straight downstairs to check on him and hes waiting there like he wants me to feed him I grab so food he eats it and chases the plecos like nothing happened.

What happened to him.

Sounds serious like a airbladder problem, recently the only Dutch eigenmanni died because of this.
If it happens again, reduce waterlevel as far as possible (fish height) so the amount of air in the bladder can be kept constant for 8 hours.
Then slowly increase the temperature with 3 degrees every 24 hours to a max of 34 Celsius, so the regulation of air starts up slowly. Keep it like that for a week, so the bladder can fix itself. After that the temperature can be reduced to normal.

If it's caused by an air bladder infection, that's the best chance you have and the only possible cure I know of.

How do they get an air bladder infection, he did eat a lot the night before.


I checked on him today and he looks fine now.

Most air bladder infections are caused by sudden drops in temperature. A bacterial infection is another option.
It looks like he's cured himself, so no problem I guess. Just keep an eye on him, if it happens again I would consider the possibility of a bacterial infection to the air bladder...

He must have had a bacterial infection, the temperature has not changed. I will keep a close eye on him but he looks like he is OK.