Silver Shark Problem

[SPO-00L]

its about 5mm wide (circle) and looks about 2-3mm deep. Ill give it a couple more days to see if he calms down a bit. it will be a week tomorrow since he has been in the tank. ill go to another fish store tomorrow and see if they have any larger sharks. In Australia, its not everyday you come across a shop that sells a 10-11" silver shark

 

[WILDER]

I wouldn't add anymore fish to be honest till you know whats wrong.
The sores sounds bad I would add some melafix to stop it getting infected.