gibbiceps pleco

[lambpie89]

hi, my gibbicepps is developing a patch all alongs its back that kinda looks like a snakes just before it sheds its skin. hes feeding normally and does not seem bothered by it but i am.
I have recently had a number of fatalities in my tank from a possible bacteria outbreak and i hope this is not connected to my pleco condition.
any suggestions or information welcome