Pascal Kobeh / Aggregation of thousands of Spider crabs (Leptomithrax gaimardii) for moulting, South Australia Basin, Australia. Pacific Ocean.

Pascal Kobeh / Aggregation of thousands of Spider crabs (Leptomithrax gaimardii) for moulting, South Australia Basin, Australia. Pacific Ocean.

Alex Mustard / Three hairy sea spiders (Tanystylum grossifemorum) feeding on red soft coral (Gersemia rubiformis). Browning Pass, Port Hardy, Vancouver Island. British Columbia. Canada. North East Pacific Ocean.

Alex Mustard / 2020VISION / Great spider crab (Hyas araneus) on Deadman's fingers (Alcyonium digitatum) coral, feeding in a current, Loch Carron, Ross and Cromarty, Scotland, UK, April

Juergen Freund / X-ray of shell of spider conch {Lambis chiragra}

Jeff Rotman / Spider crab {Schizophrys sp} on soft coral {Dendronepthya sp} Bismarck sea, Papua New Guinea

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.

Shane Gross / Arrow crab (Stenorhynchus seticornis) on coral. Eleuthera, Bahamas.

Pascal Kobeh / Spiny spider crab (Maja brachydactyla), Sulu sea, Philippines

Nick Hawkins / A common spider crab, (Libinia emarginata) camoflages among a group of frilled anemones (Metridium senile) off Bonaventure Island in the Guld of Saint Lawrence, Quebec, Canada. September.

Alex Mustard / Soft coral crab (Hoplophrys oatesil) climbing out onto a branch of yellow and red soft coral (Dendronephthya sp.) at night. Anilao, Batangas, Luzon, Philippines. Verde Island Passages, Tropical West P...

Alex Mustard / Neck crab (Podochela sp.) lives cryptically on a deepwater sea fan (Iciligorgia nodulifera). East End, Grand Cayman, Cayman Islands, British West Indies. Caribbean Sea.