I have a small (about 7") snowflake eel in my quarantine tank right now. I've had him about 5 days or so. He was looking ok but all of a sudden this evening he had 3 or 4 round white bumps on his head that look like tumors. It looks kind of like there is a small marble under the skin. They are irritating him and he keeps shaking his head. Any ideas on what this is and how to treat it? I'll try to get pictures while the lights are on later today.