Gary Bell/ Oceanwide / Scarlet Cleaner Shrimp (Lysmata amboinensis) cleaning Honeycomb Moray Eel (Gymnothorax favagineus), Tulamben, Bali, Indonesia

Gary Bell/ Oceanwide / Scarlet Cleaner Shrimp (Lysmata amboinensis) cleaning Honeycomb Moray Eel (Gymnothorax favagineus), Tulamben, Bali, Indonesia

Pascal Kobeh / Eyespot shrimp / Green marble shrimp / Spotted marbled shrimp (Saron sp., may be Saron neglectus) hidden in coral, Sulu sea, Philippines

David Fleetham / Golden rabbitfish (Siganus guttatus) being cleaned by Holthuis cleaner shrimp (Periclimenes holthuisi), Mabul Island, Malaysia.

David Fleetham / Spotted cleaner shrimp (Periclimenes yucatanicus) on its host anemone, Bonaire, Caribbean.

Franco Banfi / Giant Caribbean sea anemone (Condylactis gigantea) with Spotted cleaner shrimp (Periclimenes yucatanicus) Santa Lucia, Camaguey, Cuba. Caribbean Sea, Atlantic Ocean

Franco Banfi / Marble shrimp (Saron sp.) Raja Ampat, Irian Jaya, West Papua, Indonesia, Pacific Ocean

Pete Oxford / Spotted Cleaner Shrimp (Periclimenes yucatanicus) on Giant Caribbean Anemone (Condylactis gigantea), Bonaire, Netherlands Antilles, Caribbean

Luciano Candisani / Spotted Cleaner Shrimp (Periclimenes yucatanicus) on Giant Caribbean Anemone (Condylactis gigantea), Santa Barbara Island, Abrolhos Islands, Bahia, Brazil

Luciano Candisani / Spotted Cleaner Shrimp (Periclimenes yucatanicus) on Giant Caribbean Anemone (Condylactis gigantea), Santa Barbara Island, Abrolhos Islands, Bahia, Brazil

Luciano Candisani / Spotted Cleaner Shrimp (Periclimenes yucatanicus) on Giant Caribbean Anemone (Condylactis gigantea), Santa Barbara Island, Abrolhos Islands, Bahia, Brazil

Claudio Contreras / Spotted cleaner shrimp (Periclimenes yucatanicus) amongst tentacles of Giant anemone (Condylactis gigantea) Puerto Morelos National Park, Caribbean Sea, Mexico, January

Fred Bavendam / Spotted Moray (Gymnothorax isingteena) being cleaned by Scarlet Cleaner Shrimp (Lysmata amboinensis), Bali, Indonesia

Fred Bavendam / Spotted Moray (Gymnothorax isingteena) being cleaned by Scarlet Cleaner Shrimp (Lysmata amboinensis), Bali, Indonesia

Fred Bavendam / Spotted Moray (Gymnothorax isingteena) being cleaned by Scarlet Cleaner Shrimp (Lysmata amboinensis), Bali, Indonesia

Scott Leslie / Spotted Cleaner Shrimp (Periclimenes yucatanicus) on anemone, Bonaire, Caribbean

Fred Bavendam / Spotted Moray (Gymnothorax isingteena) beeing cleaned by Scarlet Cleaner Shrimp (Lysmata amboinensis), Bali, Indonesia

Doug Perrine / Spotted cleaner shrimp {Periclimenes yucatanicus} in Giant sea anemone {Condylactis gigantea} Dominica, Caribbean

Fred Bavendam / Spotted Cleaner Shrimp (Periclimenes yucatanicus) on Sea Anemone, Bonaire

Doug Perrine / Spotted cleaner shrimp in symbiotic relationship with anemone {Periclimenes yucatanicus} Bonaire, Caribbean (Non-ex).

Constantinos Petrinos / Spotted moray eel with cleaner shrimp {Gymnothorax moringua} Bonaire Caribbean

Joel Sartore / Photo Ark / Marbled shrimp (Saron marmoratus) portrait, The National Aquarium, Abu Dhab. Captive, occurs in Indo-Pacific Ocean.

David Fleetham / Whitemouth moray eel (Gymnothorax meleagris) with mouth open, resting in rock crevice on the ocean floor, being cleaned by a Scarlet cleaner shrimp (Lysmata amboinensis), Hawaii, Pacific Ocean.

David Fleetham / Cleaner shrimp (Urocaridella antonbruunii) looking for parasites on a Coral grouper (Cephalopholis miniata), Yap, Micronesia, Pacific Ocean.

David Fleetham / Blackspotted puffer (Arothron nigropunctatus) curled up on the reef for the night, with a transparent cleaner shrimp (Urocaridella antonbrunii) inspecting its tail, Philippines.