A friend Asks....
I have a black moor that has a lump on it's head that just appeared today, can you help me? the fish has been laying on the bottom and swimming upside down for a little while, I have tried two different tank treatments to no avail.
Ask Goldfish Care
Unfortunately It sounds like your fish has contracted something that is probably terminal, occasionally fish are born with lumps and other defects in these cases it is not abnormal for the fish to live a long healthy life. In your case the fact the fish is swimming upside down & acting in an unhealthy manner suggests it may have a tumor or another disease possibly Lymphocystis or Nodular Disease both are very serious.