Gold Barb Swimming with Mouth Open

[Magaratz]

After 60 years of having fish, I’m a little stumped on this one. One of my gold barbs is swimming with its mouth open. The only thing I can think of is I fed some small hunks of sinking wafers for the corys and YoYo loach. I didn’t watch all of the feeding, but the gold barbs seem to love them also. I have even seen them swim with an oversized bite in their mouth. Anyone see any possibility that he bit off more than he can chew?