Butterfly bloated stomach.

[Cleo642]

I don't believe it was constipation, from what I observed I'm 99% certain it was not constipation.

I fed blackworms & clams every now and again, his diet was mostly a huge variety of different frozen foods. Would I like to feed blackworms more often?? Yes. But not really practical for me to do so all the time.

I had the butterfly for nearly 1 year. So I'm not totally sure that treating Popeye in the Quarantine stage was what caused this over 9 months later. If so, that's confusing, I believed that treating the Popeye prior to moving him to the DT was the correct thing to do [emoji22]

Awe, did you get another butterfly or fish?

 

[iReefer12]

No, I already was fully stocked and I'm just not looking to add any more fish right now, I have a lot of juveniles that will be fun to see grow but important not to overstock.

 

[mcarroll]

That probably wasn't the right treatment is all - I've never lost a fish to pop eye and never used any treatment beyond a fresh water dip (which doubtfully did anything) and giving the tank an extra spic-and-span cleaning.

"Pop eye, formally known as exophthalmia, can be caused by vitamin A deficiency, tumours, bacterial infection, gas embolism and rough handling. Pop eye caused by vitamin A deficiency can often be cured by an improved diet with more vitamin A. Pop eye caused by tumours or rough handling can be hard to do treat and it is unfortunately often up to the fish itself to try to recuperate from. Gas embolism and bacterial pop eye can often be treated with penicillin or amoxicillin." -- Link.​

Nutrition and rough handling are the most likely causes. Plus if the fish didn't have an infection, Antibiotics use can open up room while the fish is recovering for something like Mycobacterium to take a permanent hold in the fish where it doesn't permanently belong, beginning an uphill struggle for the fish.

It's a slow-growing bacteria, and if it started from a small foothold that your fish has been trying to fight off, but to which he ultimately succumbed, the timeframe doesn't seem too crazy. (IANAMycobacterium expert though!)

If he had been pooping throughout the whole affair though, constipation per se is definitely is out.

Also, FWIW, even if you got your Mycobacteria diagnosed and I.D. confirmed, the treatment is long (three months), not that easy and apparently not assured of success. The recommendation I've seen (and what I've done in several bad cases) for these fish when they get to a point, is to euthanize them.