Glofish shark not eating

[soholounge]

Hi, my Glofish cosmic blue shark is not eating. In fact, I never really see his mouth move. I bought him a few days ago and just noticed this about his mouth (not sure if that was how he was originally). He is very active otherwise and swims around quite a bit - maybe almost too much at time? When he is active, he's up at the top quite a bit (not all the time) but he's not gasping for air - which may have to do with him not moving his mouth much? I also have tiger barbs in the same tank and they are all doing great.

I don't know the water test levels, but have been to pet smart every day since I've gotten him with a water sample and they said that the water is perfect. Also cycling water, using a conditioner. Temperature is good, in mid to upper 70's.

Would really appreciate any suggestions. Thanks!