Nick Garbutt / Aggregation / bloom / swarm of Moon Jellyfish (Aurelia aurita) in the clear waters of Loch Na Keal, off the Isle of Mull, north west Scotland, UK, June, Photographed through the surface.

DOC WHITE / Blue whale underwater close-up of head and mouth feeding with pouch inflated, Mexico

Gary Bell/ Oceanwide / Grey Nurse Shark (Carcharias taurus), Solitary Islands Marine Park, New South Wales, Australia

Sandesh Kadur / Blue wildebeest (Connochaetes taurinus) crossing a river, Serengeti National Park, Tanzania.

Theo Bosboom / Large group of Common blue damselflies (Enallagma cyathigerum) including mating couples - on stems of grass, Hondenven, Tubbergen, The Netherlands. June.

Frederique Olivier / Wide angle shot of a large flock of Blue footed boobies (Sula nebouxii) taking off from the sea and diving on a bait ball, Isla Lobos de Terra, Peru.

Frederique Olivier / Wide angle shot of a large flock of Blue footed boobies (Sula nebouxii) taking off from the sea and diving on a bait ball, Isla Lobos de Terra, Peru.

Ingo Arndt / Vogelkop bowerbird (Amblyornis inornatus) decoration material (blue rotten wood) collected in order to attract females to his bower, Arfak Mountains, Irian Jaya, New Guinea, Indonesia.

Ingo Arndt / Olive ridley sea turtles (Lepidochelys olivacea) females coming ashore at twilight during an arribada (mass nesting event) to lay eggs, Pacific Coast, Ostional, Costa Rica.

Ingo Arndt / Bed of Blue mussels (Mytilus sp.) densely packed together on rock, Lamberts Bay, South Africa

Ingo Arndt / Cape Gannet (Sula capensis) perched on a rock whilst calling, nesting colony, Lamberts Bay, South Africa.

Jim Brandenburg / American Bison (Bison bison) herd on prairie with quartz, Blue Mounds State Park, Minnesota