My Puffers: 3 pea puffers/dwarf puffers in a 20 G freshwater planted tank 29 G community tank with plecos, bamboo shrimp, khuli loaches, swordtails, neon tetras and apple snails
I reckon that they have probably gorged themselves and are therefore suffering from not being able to take in as much oxygen so are actually gasping rather than yawning.
Could also be that they are getting the bloodworm stuck in their teeth and are in serious need of a toothpick!
My Puffers: 3 pea puffers/dwarf puffers in a 20 G freshwater planted tank 29 G community tank with plecos, bamboo shrimp, khuli loaches, swordtails, neon tetras and apple snails
Mine occasionally does that after feeding, my F8s do that too. It could be maybe stretching? Or maybe they are way to full?? Or just plain yawning because normally when my F8s do that, I'll catch them retreating into theor caves to sleep.