Not a trick question... am I fat? Mandarin related

[BraxtonF]

Looks a little skinny, I would try different feeding methods

 

[jsvand5]

Doesn't look any fatter than OP's pics in my opinion.

The line behind the pectoral fin is it’s rib cage and you can easily see its sunken stomach in the pic. It is a very emaciated fish.

 

[bluprntguy]

I agree he looks pretty thin. I'd consider hatching some live baby brine and feeding a couple of times a day. You can also try feeding frozen baby brine and decapsulated brine shrimp eggs if he's eating frozen food. I feed for a half hour with all the pumps off so the mandarin has plenty of time to eat. You may also want to consider building one of @Paul B's brine shrimp feeding stations (https://www.reef2reef.com/threads/thanks-paulb-mandarin-feeder.263752/)

You can also feed Grindal Worms. They are really easy to culture and mandarins usually love them (as do the rest of the fish).

 

[Paul B]

That fish is very skinny and probably won't last long.
It is a waste to buy pods and they are a fortune. If your tank itself doesn't have enough natural food you can build a feeder very simply. My mandarins live over ten years and constantly spawn but they need lots of food.
I wrote this about mandarins. Good luck, I hope he makes it.

Paul B’s Unique Perspective on Keeping Mandarins

Hobby pioneer Paul “Paul B” Baldassano is not your grandfather’s reefkeeper (though he is old enough to be your grandfather!). In fact, Paul B’s perspective on just about any aspect of the marine a…

www.saltwatersmarts.com

And here is a feeder I invented for them.