Longnose Butterfly's Gross Bump

think our Longnose Butterfly has a problem. Last night he was perfectly normal looking. This morning he has a large ugly boil-like lump on his right side beneath his eye. It looks reddish sometimes but the pictures I've (hopefully) included don't seem to show the redness. He's very active and is eating as he normally does.

He is in a 180 Gallon reef tank. (Forgive me for this but) the salinity, alk, pH, nitrates, nitrites, calcium and ammonia levels are all well within normal range and have been each week for the past year. We test weekly and do waterchanges weekly using ro/di water for the change.

There are about 190 lbs of Live Rock, 3 - 4 inches of live sand the regular clean up crew of snails and hermit crabs with 2 serpent stars, a sea cucumber?? 2 mithrax crabs and a lonely peppermint shrimp. I think that's it.

He has been in the tank for 1-1/2 years and is housed with 3 chromis, 3 pj cardinals, 2 false percula clowns, a sixline wrasse and a pink barred shrimp gobie. The latest addition to the tank was the transfer of the gobie from our nano tank which was in good health (the whole tank). The latest "outside" addition is the 6 line wrasse which was added 4 months ago. All fishes are healthy and active.

The first picture was taken at 11 a.m this morning the second was taken at 7:45 pm this evening.

Please help me identify what's wrong so I can help him!
None of the other fish in the tank are showing signs of what is happening to the butterfly.

So..... Can anyone give me some idea of what is happening to this fish and what can be done to help?

correction: the first picture is a frontal view from this mroning, the second picture was taken this evening and THIS picture was taken at 11 a.m this morning. Sorry for the flub up

...... but I still need HELP!

That is weird, I'm sorry I can't help, but I've never seen that before. I hope someone else will chime in here.

looks like a pimple

hard to get a good look with the pics, but it looks like it may be an anchor worm...? Has it always looked just like that? If it was an anchor worm you would have seen it hanging from the wound and it eventually just falls off after laying its eggs in your fish.

Cant tell much from the pics so ill give you one more option. possible the fish got stung by a bristle worm or something. good luck. without some very clear close up pics it is not possible to render a good guess. keep us posted.

well when i had my red parrot freshwater fish one had this same thing theirs nothing really tat i did it just took about a month and a half to dissappear

i really does look like a pimple
sometimes it will dissappear and come back but as to what it is i dont know sorry

as long as it eats normally and satys active i wouldnt worry