Fred Bavendam / Pacific Giant Octopus (Enteroctopus dofleini) using its suction discs to hold two crabs it has caught, Quadra Island, British Columbia, Canada

Gary K. Smith / Domestic chickens outside snow covered coop on allotment, showing rat protection discs, England, January

Pete Oxford / Spix's Disk-winged Bat (Thyroptera tricolor) flying showing discs on feet, Yasuni National Park, Amazon, Ecuador

Jane Burton / Clicker training tool and dog-training discs

Duncan Mcewan / Lichen {Baeomyces rufus} with hymenial discs on Oak {Quercus} Scotland, UK

Norbert Wu / Octopus (Octopus sp) close-up of tentacles and suction discs, Tsukiji Market, Tokyo, Japan

Philip Stephen / Crewmen working on a fishing net as the rubber rock hopper discs are lowered over the stern ready to be cast into the sea, August 2006.

Nigel Cattlin / Spangle gall wasp (Neurotus quercusbaccarum) galls on underside of Oak (Quercus robur) leaf. Berkshire, England, UK.

Nigel Cattlin / Tractor with a Simba power disc harrow cultivating set-a-side field before planting with maize in Devon, April

Nigel Cattlin / John Deere tractor with a Simba power disc harrow cultivating set-a-side field before planting with maize in Devon, April