Nice looking little puffer! How often are you feeding? When I feed mine larger meals close together, there are days where he reacts to the feeding tongs but wont eat. Thankfully mine is not picky and after a day or so is back to his usual self. I will feed tilapia to mine as a filler but I feel like the fillets are not that nutritious so I use the whole silversides because it has all the gut loaded stuff they have eaten. But in the end its always a wiggly worm that breaks them if they decide not to eat. I guess if it were my puff and it was at least a week of not eating... I would probably give in and and do a worm.