I just picked this pike up from a friend and it looks like crap. Swims around fine like nothing is wrong but it looks like something is eating away at it's head and back.
Could it be a fungus or does it look more like HITH. Either way I would say try pimafix, melafix, bump the temp up a lil and add a some salt to the tank. Do a nice water change before you start treatment. Hope this helps.