Foxface getting thin in recent months

[imanewbies]

I've had a magnificent foxface(Siganus Magnificus) for around 1.5yrs. In recent months, I've noticed that fish is getting thinner and despite increasing the feeding in the recent 2-3 weeks the fish does not seem to get any fatter.

The fish is fed on a diet of pellets(Ocean Nutrition Formula 1 & Formula 2) & nori. 2 weeks back, I bought 3 rocks of red bamboo macroalgae for it in hopes of improving the situation but to no avail.

The belly area is slightly bloated but I believe that is likely to be due to the fish gorging on the macroalgae and other food i feed.

Any suggestions on what might be the problem? I'm suspecting internal parasites.

The other fishes in my tank are doing fine.

 

[sedor]

Does it act sluggish?

Maybe you could start offering meatier food as well? If I remember correctly foxfaces are omnivores.

 

[imanewbies]

Nope, its still very active and eats like a pig. No noticeable change in behaviour since day 1.