One creature on Australia's Great Barrier Reef is challenging our understanding of fish intelligence.

A tuskfish. And you can see why it gets its name.

He does something few would have believed a fish could do.

Every morning he travels to the edge of the reef.

He is searching for something special to eat amongst the coral rubble and sand.

Here is one. A small clam. But how to crack it open and get to the meat?

He takes it all the way back to his special kitchen.

A bowl-shaped coral that has a particular bump on the inside that he always uses.

It's not easy if you have no hands.

Whoops, there he goes again. But he's got great determination and surprising accuracy.