Ralph Pace / Silky Shark (Carcharhinus falciformis), Galapagos Shark (Carcharhinus galapagensis), Dusky Shark (Carcharhinus obscurus), and Black-tip Shark (Carcharhinus limbatus) group working with Yellowfin Tuna...

Ralph Pace / Silky Shark (Carcharhinus falciformis), Galapagos Shark (Carcharhinus galapagensis), Dusky Shark (Carcharhinus obscurus), and Black-tip Shark (Carcharhinus limbatus) group working with Yellowfin Tuna...

Matthew Maran / Great created grebe (Podiceps cristatus) with chick following, and person swimming in pond, Hampstead Heath, London, July 2014.

Jeff Rotman / Close up of Goggle eye / Bigeye fish (Priacanthus hamrur) Red Sea, Egypt

Georgette Douwma / Big-eye or Goggle-eye (Priacanthus hamrur) on wreck. Note colour change from deep red to silver. Egypt, Red Sea

Georgette Douwma / Bigeye / Goggle-eye (Priacanthus hamrur) showing colour change from deep red to silver. Sipadan, Malaysia.

Norbert Wu / Bottlenose Dolphin (Tursiops truncatus) chases a school of Bigeye Scad (Selar crumenophthalmus), Roatan, Honduras

Peter Scoones / Goggle eye / Common bigeye fish schooling {Priacanthus hamrur} Sipadan, Malaysia

Sue Flood / Photographer Sue Flood taking picture of herself and colony of Emperor penguin (Aptenodytes forsteri) in reflection of someone's goggles, Gould Bay, Weddell Sea, Antarctica.

Georgette Douwma / Big-eye or Goggle-eye (Priacanthus hamrur) and Crown squirrelfish (Sargocentron diadema) on wreck colonised by corals, Red Sea, Egypt. January.

Georgette Douwma / Big-eye or Goggle-eye (Priacanthus hamrur) with some changing colour from silver to bright red and back again. Andaman Sea, Thailand.

Pascal Kobeh / Atlantic bigeye (Priancanthus arenatus) Sal Island, Cape Verde. Atlantic Ocean.