Why do morays keep opening their mouths?

Watch a moray’s mouth open and close. Those steady movements help water flow over its gills. The gills take oxygen from the water.

Follow the water. It goes in through the mouth, washes over the gills and slips out through tiny openings just behind the head.

A crack in the rock makes a snug hideout. A moray can stay tucked inside with just its head poking out. It can breathe right where it is.

The jaws you can see do the catching. There’s another set tucked away in the throat. Those hidden jaws help the moray swallow its meal.