Gary Bell/ Oceanwide / Scarlet Cleaner Shrimp (Lysmata amboinensis) cleaning mouth of Tomato Grouper (Cephalopholis sonnerati), Great Barrier Reef, Australia

Gary Bell/ Oceanwide / Scarlet Cleaner Shrimp (Lysmata amboinensis) cleaning mouth of Tomato Grouper (Cephalopholis sonnerati), Great Barrier Reef, Australia

Alex Mustard / Commensal emperor shrimp (Periclimenes imperator) moves across the colourful red patterned surface of its host Candycane sea cucumber (Thelenota rubralineata). Misool, Raja Ampat, West Papua, Indonesi...

Shane Gross / Bubble coral shrimp (Vir philippinensis) on Bubble coral (Plerogyra sp). Anilao, Philippines.

Juergen Freund / Moral eels, Urchins, Cuttlefish, Shrimp and other marine life living within a discarded tyre and fishing net under a ships' harbour, Maluku, Indonesia. November.

David Fleetham / Cleaner wrasse (Labroides dimidiatus) swimming alongside Golden damsel (Amblyglyphidodon aureus) looking for parasites, Fiji, Pacific Ocean.

David Fleetham / Bubble coral shrimp (Vir philippinensis) on Bubble coral (Plerogyra sp), Philippines.

Solvin Zankl / GEOMAR / Polar shrimp (Lebbeus polaris) on live Lophelia (Lophelia pertusa) from Trondheimfjord, North Atlantic Ocean, Norway. Controlled conditions. Photo taken in cooperation with GEOMAR coldwater coral res...

David Shale / Male and Female glass shrimps on Glass sponge (Hexactinellida) from coral seamount, SW Indian Ridge, Indian Ocean, December 2011

Alex Mustard / Pederson cleaner shrimp (Periclimenes pedersoni) cleaning the eye of a Nassau grouper (Epinephelus striatus), Bloody Bay Wall, Little Cayman, Cayman Islands. British West Indies, Caribbean Sea.

David Shale / Deepsea Orange ghost lobster (Decopoda, Thalassinidae) from coral seamount in the Indian Ocean, December 2011

Alex Mustard / 2020VISION / Skeleton shrimp (Caprella linearis) living within the polyps of Dead man's fingers soft coral. Bard Cave, Bressay, Shetland Islands, Scotland, UK, June