Juergen Freund / Arrow crab on sponge (Stenorhynchus seticornis) Caribbean

Chris Newbert / Decorator Crab, holding a broken piece of Sea Fan as camouflage, night, Red Sea

Fred Bavendam / Sponge Crab (Austrodromidia octodentata) wearing a hat of yellow sponge for camouflage, Edithburgh, South Australia, Australia

Fred Bavendam / Sponge Crab (Austrodromidia octodentata) wearing a Hat of Leach's Compound Ascidian (Botrylloides leachi) instead of a Sponge, South Australia

Alex Mustard / Sleepy sponge crab (Dromia dormia) climbing over a rock, carrying its sea squirt (Didemnum molle) disguise, with brittlestar. Anilao, Batangas marine protected area, Luzon, Philippines. Verde Island P...

Alex Mustard / West Indian spider crab (Mithrax spinosissimus) shelter in a giant barrel sponge (Xestospongia muta) on a coral reef. Jardines de la Reina, Gardens of the Queen National Park, Cuba. Caribbean Sea.

SCOTLAND: The Big Picture / Hermit crab (Pagurus bernhardus) on yellow sponge, Loch Etive, west coast of Scotland, UK, September.

SCOTLAND: The Big Picture / Hermit crab (Pagurus bernhardus) sat on yellow sponge, Loch Etive, west coast of Scotland, UK, August.

David Fleetham / Slender spongegoby (Phyllogobius platycephalops) and two Crabs of different species on Sponge. Several parasites with egg cases on the side of the Goby. Philippines.

Sue Daly / Sponge spider crab (Inachus) in a Snakelocks anemone (Anemonia viridis), Sark, British Channel Islands, UK, September.

Sue Daly / Sponge spider crab (Inachus) in a Snakelocks anemone (Anemonia viridis), Sark, British Channel Islands, UK, September.

Sue Daly / Sponge spider crab (Inachus) in a Snakelocks anemone (Anemonia viridis), Sark, British Channel Islands, UK, September.