Piranha Needs Help!

[annis_2006]

I've had a piranha for about 3 years now. He's had something up with his gil since he was a little kid, i've tried chemicals and whatnot, but they did nothing. Anyway, recently he's been ocassionally swimming sideways and (it looks like) scratching his side. There is also a feeder fish in his tank that he won't eat -- the little feeder fish (about 1" long) goes up to the piranha (about 6" long) and nips at him. the feeder fish isnt biting the piranha's fins or anything, he's biting at his gil/mouth/eye area, and the piranha just swims away. i have no idea if any of it is at all related... any ideas as to whats up?
-kyle

 

[WILDER]

Not worth feeding feeder fish they can carry desease and also there not much nutrition in them.
The gills can you explain what you mean.
When fish peck as other fish can be flukes.
Do the gills look pale with excess mucas on them or red and inflamed.

 

[WILDER]

Wondering if your fish has flukes they can also get them internally as well as externally.
Laying to onside can be a sign of a parasite.