Betta missing half of operculum

[Enchantress]

Hi all,
My male betta (whom I've had for just over 7 months, but he was already an adult when I adopted him) seems to be missing half of his operculum (the 'beard'). When he flares, the right hand side opens up perfectly, but the left one just isn't there. The gill cover opens well enough, but the beard underneath is not visible. When his mouth is closed, the left hand side of his face/gills (the one with the missing operculum) seems just a little bit asymmetrical/droopy. He doesn't flare that often, and I don't make him do it that frequently, but from what I can remember he didn't use to have this problem before. Otherwise he's healthy - ravenous appetite, active, good colours, not under- or overweight. The only culprit I can think of is the fact that about a month ago I left home for about 2 weeks and the state of his tank deteriorated significantly (lots of gunk on the bottom), and he was in pretty bad shape - he didn't seem to eat that much, even though I'd left him some 'holiday food'. He lost weight and also developped mysterious small bumps on his body, but I remember he had one or two of those when I got him, so I'm not sure what the cause is. I'm quite sure, though, that my absence resulted in him losing some of his immunity, so this could also have contributed to some of the issues. Nonetheless, I'm at a loss as to what I should do - will the bumps disappear, and will the operculum grow back? Or have I messed up too bad? Since my return I have brought his tank (and the fish itself, to some extent) back to its original condition, but I'm still a bit concerned that my carelessness will cause him to suffer, so I'd appreaciate some input as to the prognosis for both the operculum and those bumps. They don't seem to be causing him any distress - like I said, he's eating very well and acting normal (he doesn't build bubble nests anymore or patrol the tank/flare at random snails, and he used to do it quite frequently, but maybe he's just had a change of heart?). I don't know. Anyway, thanks in advance for any input.

 

[Delapool]

Hi, hopefully it grows back. It sounds like some sort of infection so first imo would be a check of water chemistry. Lots of temp-matched, clean water changes and good gravel vacs may be enough by itself.


I have bought a auto-betta feeder but yet to try it. The holiday feeders that go into the water I tend to skip if just a few days and don't really like them.

 

[Enchantress]

Well, I've moved him to a sterile quarantine tank (bare bottom, no decor, just a heater & filter) and I plan on letting him soak in CMF for about 7 days - I know it sounds like overkill, but I want to be sure I've done everything I can. The lighting in this tank is much better, so I was able to take a closer look at him and can now confirm that indeed, his left operculum is missing. Just straight up gone. Even with closed gill covers, you can still tell the difference - the left one is thin and flat against his body, while on the right hand side it seems fuller and the operculum is clearly visible under the gill. Could it be a bacterial infection? And how long do you think it'll take before it grows back (if it does at all, but fingers crossed)?

 

[Delapool]

Can you get a photo? Might be genetic.

 

[Enchantress]

I don't think it's genetic, because I'm pretty certain he didn't use to look like this before. I'll try to get a pic, but I doubt I'll manage to snap one when he's flaring and darting around - so no guarantees, but I'll see what I can do So far it seems to bother me more than it does him, but it would certainly be comforting to see it grow back, or at least know that it doesn't affect him in any way.

 

[Autumnsky]

If the water quality was bad it could have become infected and eroded. With time and clean water a healthy diet, possibly could grow back.

What are the bumps? A pic would be helpful. Wondering about a parasite?

Look with a good magnifying glass at gills, body and eyes, mouth, anal vent to see if there could be fish lice - you can do an image search to get an idea about what that looks like, or tiny worm things that can peek in and out of the area, etc. Basically any moving looking thing which wouldn't be on a healthy fish.