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

Gary Bell/ Oceanwide / Scarlet Cleaner Shrimp (Lysmata amboinensis) cleaning female Stocky Anthias (Pseudanthias hypselosoma), Tulamben, Bali, Indonesia

Gary Bell/ Oceanwide / Scarlet Cleaner Shrimp (Lysmata amboinensis) cleaning Yellow-edged Moray (Gymnothorax flavimarginatus), Tulamben, Bali, Indonesia

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 mouth of Goldbelly Cardinalfish (Apogon apogonides), Tulamben, Bali, Indonesia

Alex Mustard,Alex Mustard / A portrait of a small Candy stripe shrimp (Lebbeus grandimanus) in front of its host pink anemone (out of focus because of the magnification). Browning Wall, Browning Pass, Port Hardy, Vancouver Islan...

Chris Newbert / Scarlet Cleaner Shrimp (Lysmata amboinensis) pair cleaning a Moray Eel (Gymnothorax ocellatus) 80 feet deep, Solomon Islands

Fred Bavendam / Scarlet Cleaner Shrimp (Lysmata amboinensis) working on a Tomato Grouper (Cephalopholis sonnerati), Milne Bay, Papua New Guinea

Sergio Hanquet / Shrimp (Trachycaris restricta), close up. Tenerife, Canary Islands.

Sergio Hanquet / Shrimp (Trachycaris restricta), close up. Tenerife, Canary Islands.

Sergio Hanquet / Red-backed cleaner shrimp (Lysmata grabhami) on sandy sea floor. Tenerife, Canary Islands.

Sergio Hanquet / Red-backed cleaner shrimp (Lysmata grabhami), view from above. Tenerife, Canary Islands.

Sergio Hanquet / Red-backed cleaner shrimp (Lysmata grabhami) head, close up. Tenerife, Canary Islands.

Sergio Hanquet / Red-backed cleaner shrimp (Lysmata grabhami). Tenerife, Canary Islands.

Sergio Hanquet / Red-backed cleaner shrimp (Lysmata grabhami). Tenerife, Canary Islands.

David Hall / Banded tozeuma shrimp (Tozeuma armatum) on Black coral (Antipatharia). Komodo, Indonesia.

Gary Bell/ Oceanwide / Scarlet Cleaner Shrimp (Lysmata amboinensis) cleaning Yellow-edged Moray (Gymnothorax flavimarginatus), Tulamben, Bali, Indonesia

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 mouth of Goldbelly Cardinalfish (Apogon apogonides), Tulamben, Bali, Indonesia

Gary Bell/ Oceanwide / Emperor Angelfish (Pomacanthus imperator) juvenile being cleaned by Scarlet Cleaner Shrimp (Lysmata amboinensis), Tulamben, Bali, Indonesia

Gary Bell/ Oceanwide / Emperor Angelfish (Pomacanthus imperator) juvenile being cleaned by Scarlet Cleaner Shrimp (Lysmata amboinensis), 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

Jordi Chias / Shrimp (Chorismus antarcticus) Antarctic Peninsula, Antarctica.

Georgette Douwma / Ocellated tozeuma shrimp (Tozeuma lanceolatum). West Papua, Indonesia. Indo-West Pacific.

Georgette Douwma / Ocellated Tozeuma Shrimp (Tozeuma lanceolatum). West Papua, Indonesia. Indo-West Pacific.

Pascal Kobeh / Saw blade shrimp or Tozeuma shrimp (Tozeuma armatum) in a black coral, Sulu Sea, Philippines.

Franco Banfi / Polar shrimp (Lebbeus polaris) resting on rock. Tasiilaq, East Greenland. April.

Linda Pitkin / Banded tozeuma shrimp (Tozeuma armatum) on Black Coral (Antipathes sp.), Triton Bay, near Kaimana, West Papua, Indonesia

Linda Pitkin / Banded tozeuma shrimp (Tozeuma armatum) on Black Coral (Antipathes sp.), Triton Bay, near Kaimana, West Papua, Indonesia

Alex Mustard / Yellow-orange ocellated tozeuma shrimp (Tozeuma lanceolatum) on a orange-pink sponge. Bitung, North Sulawesi, Indonesia. Lembeh Strait, Molucca Sea.

Alex Mustard / Red ocellated tozeuma shrimp (Tozeuma lanceolatum). Anilao, Batangas, Luzon, Philippines. Verde Island Passages, Tropical West Pacific Ocean.

Franco Banfi / Two Ambonian / Squat shrimps (Thor amboinensis) on coral, Lighthouse Reef, Cabilao Island, Bohol, Central Visayas, Philippines, Pacific Ocean.

Bert Willaert / Marbled shrimp (Saron cf. marmoratus) moulting. Bismarck Sea, Vitu Islands, West New Britain, Papua New Guinea

Constantinos Petrinos / Ocellated tozeuma shrimp (Tozeuma lanceolatum) Lembeh Strait, North Sulawesi, Indonesia.

Constantinos Petrinos / Ocellated tozeuma shrimp (Tozeuma lanceolatum) pair. Lembeh Strait, North Sulawesi, Indonesia.

Constantinos Petrinos / Saw-blade shrimp (Tozeuma armatum) on gorgonian, Lembeh Strait, North Sulawesi, Indonesia.

Franco Banfi / Candy-striped shrimp (Lebbeus grandimanus) on Crimson anemone (Cribrinopsis fernaldi), Alaska, United States, North Pacific Ocean.

Franco Banfi / Candy-striped shrimp (Lebbeus grandimanus) on Crimson anemone (Cribrinopsis fernaldi), Alaska, United States, North Pacific Ocean.

Tony Wu / Giant moray eel (Gymnothorax javanicus) being cleaned by Scarlet cleaner shrimp (Lysmata amboinensis) Ambon, Indonesia

Tony Wu / Giant moray eel (Gymnothorax javanicus) being cleaned by Scarlet cleaner shrimp (Lysmata amboinensis) Ambon, Indonesia

Franco Banfi / Clown shrimp (Lebbeus grandimanus) on Crimson anemone (Cribrinopsis fernaldi) British Columbia, Canada, Pacific Ocean

Pascal Kobeh / Two Paron shrimps (Gelastocaris paronae) on a sponge, Manado, Indonesia. Sulawesi Sea.

Alex Mustard / High magnification portrait of Tiny hairy shrimp (Phycocaris simulans) with eggs, backlit. Secret Bay, Anilao, Batangas, Luzon, Philippines. Verde Island Passages, Tropical West Pacific Ocean.

Solvin Zankl / Humpback / Northern / Scarlet cleaner shrimp (Lysmata amboinensis) cleaning the mouth of a Banana fusilier (Pterocaesio pisang) Raja Ampat, West Papua, Indonesia, Pacific Ocean.

Michele Westmorland / Moray Eel (Gymnothorax prasinus) with Rock shrimps (Lysmata sp) in urchins and sponge encrusted rocks. Galapagos Islands.

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

Norbert Wu / Clown Shrimp (Lebbeus grandimanus) pair on Fernald Brooding Anemone (Cribrinopsis fernaldi), Vancouver Island, British Columbia, Canada

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

Fred Bavendam / Yellow-edged Moray (Gymnothorax flavimarginatus) being cleaned by Scarlet Cleaner Shrimp (Lysmata amboinensis), Bali, Indonesia

Fred Bavendam / Clown Shrimp (Lebbeus grandimanus) living with a Fernald Brooding Anemone (Cribrinopsis fernaldi), British Columbia, Canada

Norbert Wu / Clown Shrimp (Lebbeus grandimanus) and Kincaid Coastal Shrimp (Heptacarpus kincaidi) among stinging tentacles of Fernald Brooding Anemone (Cribrinopsis fernaldi), southeast Alaska

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

Chris Newbert / Squat Anemone Shrimp (Thor amboinensis) 40 feet deep, Solomon Islands

Chris Newbert / Squat Anemone Shrimp (Thor amboinensis) nestled in Sea Anemone tentacles (Actinostephanus haeckeli) 60 feet deep, Papua New Guinea

Fred Bavendam / Scarlet Cleaner Shrimp (Lysmata amboinensis) working on a Tomato Grouper (Cephalopholis sonnerati), Milne Bay, Papua New Guinea

Chris Newbert / Scarlet Cleaner Shrimp (Lysmata amboinensis) cleaning a Moray Eel (Gymnothorax ocellatus) 80 feet deep, Solomon Islands

Chris Newbert / Squat Anemone Shrimp (Thor amboinensis) portrait, 70 feet deep, Solomon Islands

Hiroya Minakuchi / Squat Anemone Shrimp (Thor amboinensis), Sulu Sea, Borneo, Malaysia

Hiroya Minakuchi / Yellow-edged Moray (Gymnothorax flavimarginatus) being cleaned by Scarlet Cleaner Shrimp (Lysmata amboinensis), Sulu Sea, Borneo, Malaysia

Birgitte Wilms / Marbled Shrimp (Saron marmoratus) on coral, Solomon Islands

Fred Bavendam / Zubi Needle Shrimp (Tozeuma armatum) lives on Black Coral (Antipathes sp) where its elongate shape and coloration make it very difficult to discern, Bali, Indonesia

Fred Bavendam / Scarlet Cleaner Shrimp (Lysmata amboinensis) working on a Tomato Grouper (Cephalopholis sonnerati), Bali, Indonesia

Gary Bell/ Oceanwide / Scarlet Cleaner Shrimp (Lysmata amboinensis) cleaning female Stocky Anthias (Pseudanthias hypselosoma), Tulamben, Bali, Indonesia

Gary Bell/ Oceanwide / Squat Anemone Shrimp (Thor amboinensis), Anilao, Philippines

Gary Bell/ Oceanwide / Squat Anemone Shrimp (Thor amboinensis) on sea anemone, Anilao, Philippines

Gary Bell/ Oceanwide / Squat Anemone Shrimp (Thor amboinensis) on sea anemone, Anilao, Philippines

Gary Bell/ Oceanwide / Zubi Needle Shrimp (Tozeuma armatum) male, Anilao, Philippines

Gary Bell/ Oceanwide / Squat Anemone Shrimp (Thor amboinensis) on camouflaged on hard coral, Lembeh Strait, Indonesia

Hiroya Minakuchi / Scarlet Cleaner Shrimp (Lysmata amboinensis) cleaning Titan Triggerfish (Balistoides viridescens)

Norbert Wu / Clown Shrimp (Lebbeus grandimanus) among stinging tentacles of Fernald Brooding Anemone (Cribrinopsis fernaldi), Vancouver Island, British Columbia, Canada

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

Alex Mustard / Cleaner shrimp (Lysmata sp.) larval stage, drifting in open water as part of the plankton, Bitung, North Sulawesi, Lembeh Strait, Molucca Sea.

Alex Mustard / Stiletto shrimp (Heptacarpus stylus) crawling down the twisted stipes of Bull kelp (Nereocystis luetkeana), Browning Pass, Vancouver Island, British Columbia, Canada, Queen Charlotte Strait, Pacific O...

Alex Mustard / Three White-eyed moray eels (Gymnothorax thyrsoideus) and Palechin moray eel (Gymnothorax herrei) with Cleaner shrimps (Decapoda) resting in a hollow log on seabed, Bitung, North Sulawesi, Indonesia,...

Jacob Guy / Close up of Hairy shrimp (Phycocaris simulans) eating. Then the animal walks further down the vegetation. Lembeh Strait, Indonesia.

Jacob Guy / Close up of Hairy shrimp (Phycocaris simulans) eating, Lembeh Strait, Indonesia.

David Fleetham / Marbled shrimp (Saron marmoratus) male resting on coral, Hawaii, Pacific Ocean.

David Fleetham / Marbled shrimp (Saron marmoratus) female resting on coral, Hawaii, 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 / Two Scarlet cleaner shrimps (Lysmata amboinensis) inspecting a Yellowmargin moray eel (Gymnothorax flavimarginatus) off Sabang Beach, Mindoro, Philippines, Pacific Ocean.

Georgette Douwma / Composite image of marine invertebrates on black background. Top row from left: Tube anemone (Ceriantharia), Yellow sea cucumber (Colochirus robustus), Nudibranch (Nembrotha lineolata), Squat shri...

Franco Banfi / Feather star shrimp (Hippolyte prideauxiana) on a Common feather star (Antedon bifida), Marine Protected area Punta Campanella, Costa Amalfitana, Italy, Tyrrhenian Sea.

Shane Gross / Candy stripe shrimp (Lebbeus grandimanus) sheltering beneath tentacles of its host, Crimson anemone (Cribrinopsis fernaldi). Browning Pass, British Columbia, Canada. North East Pacific Ocean. July.

Shane Gross / Elegant coastal shrimp (Heptacarpus decorus) on Orange sea pen (Ptilosarcus gurneyi) in Browning Pass, British Columbia, Canada. North East Pacific Ocean. July.

Joel Sartore / Photo Ark / Two Atlantic cleaner shrimp (Lysmata grabhami) full length profile, Loro Parque aquarium. Captive.

David Hall / Close up of Peppermint shrimp (Lysmata wurdemanni), Dominica, Eastern Caribbean.

Franco Banfi / Parrot shrimp (Spirontocaris spinus) in front of Arctic anemone (Bolocera tuediae), Trondheimfjord, Norway, North Atlantic Ocean.

Alex Mustard / Feather star shrimp (Hippolyte prideauxiana) in a Red feather star (Antedon bifida). This observation greatly expands the known range of this rare species of shrimp in the UK, Eyemouth, Scotland, UK,...

Alex Mustard / Deep red Feather star shrimp (Hippolyte prideauxiana) crawling secretly amongst the arms of a Feather star (Antedon bifida), Loch Duich, Highands, Scotland, UK.

David Fleetham / A close-up of a Pacific cleaner shrimp (Lysmata amboinensis), Hawaii, USA.

David Fleetham / Seven tiny Squat shrimp (Thor amboinensis) on a Malu anemone (Heteractis malu), Hawaii.

Shane Gross / Kelp humpback shrimp (Hippolyte clarki) on eelgrass (Zostera marina) off Vancouver Island, British Columbia, Canada

Sergio Hanquet / Tiger moray (Enchelycore anatina) with Red-baked cleaner shrimp (lysmata grabhami), Tenerife, Canary Islands.