I got a hatchling Mississippi Map turtle yesterday from reptiles-n-critters and noticed whenever my turtle looks up, there is sort of a pouch under his chin. Is this normal? I don't have a substrate so it couldn't be caused by gravel.
I'm not sure of the physics of it, but you normally see a slight swelling of the throat directly behind the mouth that almost makes it look like the turtle is breathing under water. It is normal and all water turtles do it.