Fish are not generally renowned for their intelligence, but new research suggests they are smarter than we thought.
Tool use, once thought to be exclusive to animals with highly developed brains, has been recorded for the first time by a fish in the wild.
Tusk fish have been photographed appearing to be smashing open cockle shells that were between two and eight millimetres thick.
The pictures were taken by Scott Gardner during a dive at Egg Rock in the Keppel Islands, a protected area of the Great Barrier Reef, in June.
The fish grasps the bivalve in its mouth and swivels its body back and forth, landing alternate blows on the sharp part of the rocks. After several blows, the bivalve cracks open and the fish eats the meat inside.
Read the complete story from The Sydney Morning Herald