Suddenly hiding anthia

[toytech]

In my 120 I have a he/she lyertail Anthia and a Carberry he/she as well (both transitional),they are best buds and are out all day , have been in the tank for several months , voracious eaters fed multiple times a day , and get along with everyone in the tank(no big tangs or aggressive fish). Suddenly the carberry has been hiding in the rockwork , breathing has increased , will come out when food is put in the tank but wont eat . No new fish have been added recently and all other fish are acting normal . Ive read several posts of people having the same problem with different anthias but no one seems to have an answer why this happens and most seem to die , but I was hoping someone here has had a different experience . Not sure what to try at this point , QT ing him will probably finish him off , but I do have antibiotics I can use in the display, but I don't want to if I don't have to .

[Coasting]

Sounds like something is stressing it.... Not necessarily that it's sick. But stress can sure lead to illness.
Perhaps try the mirror trick and distract the other fish to change up the environment a bit.
Add more anthias?

My male Lyretail did this when I switched to the new tank last month, and the Melanurus went on a 2 day attack spree against the Butterfly, and totally spazzed around the rest of the tank. He (anthias) used to be the boss on the tank and then all of a sudden I couldn't find him. Every so often he would move spots and I realised he was hiding in the rocks breathing slightly heavier/looking stressed. I tried using the mirror to keep the melanurus in 1 area and it didn't change anything with the anthias, he refused to come out of the rock. I wasn't even seeing him come out when I fed the tank.
I did then add a group of 6 red fairys and by the next day the lyretail was back out swimming and joining in with the group again. Everythings back to normal now.

[toytech]

Not sure what would stress the guy out my tank is very peaceful and there has never been any fighting between the fish , and he will come out when the tank is fed and he looks at the food but he wont eat and once its gone he goes back and hides.

[Coasting]

You could try pulling him and his buddy out into QT (lots of hidey holes would keep him calmer i think) and running a round of Prazi or something and keeping a close eye.
But I know their a Pita to catch....
I would change up the environment somehow and see if that does anything. Could very well be something we dont notice.
Do you garlic soak the food?
Tried other varieties?

Anthias can be very odd fish at times.

[toytech]

Out and eating today , though looking a bit thin , I will up the feedings and see if he/she fattens back up . Maybe transitioning to a male and was feeling self confident ?

[toytech]

Confirmed transition to a male , purple over the face appeared today and loner fins and spines on dorsal fin.

[gregzz4]

Is he eating now ?

[toytech]

Yup eating and back to his old self , he did loose a little weight though which worries me .