That is the first stages of Hexamita or as it it is better known "hole in the head"
This will not spread onto the ray or is any way associated with the spots on the ray.
You need to isolate the fish and treat with eSHa Hexamita, you can order it online.
The white puss is oozing out of the sensory pores, seen this many times, its the right diagnosis, it can take a while to clear up.
Feed Hikari Cichlid mini sinking pellets, this helps, it is a dietary problem that starts this process. I have found that South American Cichlids that are fed Hikari foods almost never develop the problem.
All my fish are great thanks, I'm still breeding a few Marbles, Pearls, Leos, hens and of course my favourite wallacei AKA hystrix.
You take care Jason,
Regards,
Richard.