If it was swim bladder, it’s very unlikely the fish would be able to control itself well enough to hide in a cave like that.
Most anthias have needs I was never able to replicate, namely the frequency of feedings. I feed my fish once per day typically, and that won’t work long-term for them, they starve out slowly, unfortunately.A ruby head wrasse, two clowns, and a pink spotted goby. They all seem perfectly fine. I'm going to try hand feeding him by trying to get some tweezers in cave. The opening is on the side of the tank so its a little awkward to get to unfortunetly. I really hope he isn't just on his way out, he was the first fish in the tank almost a year ago and I was planning on moving him and the wrasse to a new reefer 350 that I'm setting up in a couple weeks.
If weak and not getting enough sustenance, it’s certainly possible but I’m not sure how much more frequently anthias should eat, so I’m not much help.
Use some vitamin C and B12 for the stress
Yes, I have used it in different forms for many moon
. Back in the day I used to grind up vitamin c tabs and add them to the tank, then powdered vitamin c, now I use viamarin C and M from bright well. I am going to run out soon and mess around with another product. Here is an old thread here on R2R link. here are more threads here also link
