HELP for ocellaris

[pokero]

Hello to everybody,
I move this message from the cichla thread where I have had any suggestion.
My PB is around 1 month that doesn't eat anything and stay always in the corner of the tank watching to the other fish.
He is becoming more and more thin!
The fish is 5 years old ( I bought at 1,5 inch ) and 16 inches long. The tank is 600 gal , 77°F, 7.15 PH, 0.001 mg/l NH3.
In the tank there are 3 ocellaris ( 16" ) , 1 orinocensis ( 12" ), 2 astronotus , 1 pleco and 2 motoro stingray ( 6/7" )
I put some pics where you can see the difference with the brothers.
Thank you

Roberto
View attachment 1046407

 

[ReisAntonio]

Have you tried changing it´s diet? I have a Channa Aurantimaculata that is 36cm. I´ve had it since it was more or less 15cm and it spent the whole of September without eating what it already ate steadily for the past year. I gave it some feeders and it started eating again and last week I managed to start feeding it blood worms again. I know that they´re completely different fish but I hope it helps.