When an iguana opens its mouth and holds it open. This is often a behavior seen during aggressive displays. It is a threat/warning that biting may be imminent. For more information on displays, visit the Body Language page.

Crocodiles cool themselves by holding their mouths open, just like panting dogs do. Evaporation from the mouth can cool them off even while they lie in the sun for hours.

Wide Open.

Condition when shells of a bivalve do not close fully, usually as an indicator of stress.

the final stage of firing