Green Terror problem or general health problem?

Hey all,

Been away for 2 days and on return, I find my female GT with quite a big piece of her head missing. She was still alive though. A few days prior I noticed the scales on her head looking rough and thinning out. Is this a condition specific to the GT's or could there be a problem that could affect the tank? The other fish look fine (including the male GT)

Help please....?

 

Pic of your female gt please (sound like hole in the head desease)

 

can u tell us how many GT's you have (how many males and how many females) and what size tank they are in

 

Hey guys...thank you for the responses. Unfortunately, I did not take a picture of the gt. I had a pair, male and female, now it's only the male left in a 5 ft, extra width tank. Tank mates are 2 parrots. 1 convict, 1 amazon, 1 oscar, 1 malawi, 2 silver dollars, 1 pleco, 1 catfish, 1 egyptian mouth breeder...

 

Overstocking and noncompatibility might be a problem here.
What is your tanksize in Liters and exact dimensions as well as the fish sizes?