An Imperial commensal shrimp (Periclimenes imperator), photographed at night on the Spanish dancer nudibranch (Hexabranchus sanguineus), that it calls home, Philippines

animal behaviour animals arthropod arthropoda camouflaged caridea chromodorididae claw close up color image commenalism commensal coral crab crustacea crustacean decapoda directly above doridacea dumaguete emperor shrimp gastropod hexabranchidae hexabranchus hexabranchus sanguineus hidden horizontal imperial shrimp interaction invertebrate malacostracea marine life mollusc no people nocturnal orange pacific ocean palaemonoidea periclimenes imperator philippines pontoniinae rhinophore sanguineus sea life spanish dancer nudibranch symbiosis symbiotic tropical tropical climate two animals underwater arthropods asia atlantis biology crabs criptic crustaceans cushion dancer decapods dorid ecology galera imperial commensal shrimp indopacific invertebrates malacostraceans mollusca mollusk mollusks no one nobody nudibranch nudibranchia nudibranchs ocean ophistobranchia pacific periclemenes periclimenes prawn probiose protection puerto galera rare red reef refuge rhinophores sea snail seasnail shelter shrimp shrimps slug snail snails south spanish nudibranch sunda tubattaha tubbataha uncommon visayas