They open it very wide.
dory
You can't. You can only open your mouth as wide as your jaw will let you.
Open the mouth wide.
Swallow prey
Birds
because fish have no eyelids
the fish opens its mouth less as the water gets colder.
roughly 65 degrees
Wide open. A gaping hole is a wide open hole. A gaping mouth is one which is hanging open, usually from astonishment.
He stood there with his mouth gaped open, utterly shocked by what he had just heard.
Very wide. Approximately 69m.
No , nostrils are absent in fish , fish inhale water by open mouth .