1 Altum killing the rest

[Claudine]

Hi Everyone,

I have been keeping 6 Altums for the past 3 years in a 6 feet planted tank. Bought them from Gan when they were around 2 inches in diameter. They grew to nearly 1 feet high, with 'fin extension' at both ends of the tail and the dorsal fin (like antennas). Their tails and dorsal fins were red and they were my pride and joy.

After 2 days of doing a minor rescaping of our 6 feet tank, the 3 biggest ones started fighting and one died within a day with tail torn.
After 1 week, another one followed with no symptons, meaning they were eating normally the night before.

Then the nightmare started with 1 dying every week with no symptons.
We noticed earlier that the biggest Altum would flare his fins and nip the rest but only the other 2 the same size would sometimes flare back. The smaller ones will just swim away.

However, I did not do anything as the fights weren't too serious and there weren't any wounds. I did not actually get to witness how they died as I only discover them dead when I return from work.

When we fished out the dead fish, they all had nip wounds and bitten fins.
The strange thing was that I had to search high and low for the dead/missing Altums when I did my nightly count, sometimes for hours. They would be hidden in the most heavily planted area of the tank with head down and tail up.

Now there is only 1 Altum and 1 Scalare (also from Gan) left and they do not fight. Could they be male & female? Could all my other 6 Altums be all males?

Can anyone please enlighten me on why my beautiful Altums died?
Thank you very much!

[ckll]

Sorry abt the loss ..

It could be that the rescaping had upset their territories, and they were trying to establlish new territories.

Being adults now, they sure pack a meaner punch compared to the times when they were still young/juveniles.

Did you ever see any pairing-off during the 3 years ? If not, then perhaps you really had all males/all females.

[Claudine]

Thank u v much for the suggestion. Nope I have never noticed any pair forming.