It doesn't seem to spread to other fish that are in a different genus to the neons but there have been a few cardinal tetras with a similar lump on the lip. So it is probably able to jump to similar species like the green neon and cardinal tetra, but nothing else has had it.
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No info other than what I see on here.
It's not a bacterial infection because it can stay on the fish for months and people have used anti-biotics on it to no avail.
It's not a protozoan infection for the same reason, it doesn't spread over the fish and people have used medications designed to kill protozoan infections.
It's not fungus, again because it doesn't spread and people have used salt and anti-fungal treatments with no success.
That basically leaves us with a virus that seems to appear on newly imported fish or old fish. This suggests a stress induced virus. Combine this with neons in America being the fish affected but not in Australia, would suggest it's viral.
