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...

Jurgen Freund / Timelapse of Giant sea cucumbers (Thelenota ananas) moving underwater, with a Giant clam (Tridacna gigas) in the background, Great Barrier Reef, Queensland, Australia, 2015.

Alex Mustard / 2020VISION / A forest of Sea cucumbers (Psolus phantapus) feeding, extended up out of the sediment in Scottish sea loch, Loch Duich, Ross and Cromarty, Scotland, UK, April

Jurgen Freund / Sea apple (Pseudocolochirus violaceus) with tentacles exposed, feeding, Komodo NP, Indonesia, Indo-pacific.

Jurgen Freund / Imperial / Emperor shrimp (Periclimenes imperator / Zenopontonia rex) on an Eyed / Leopard sea cucumber (Bohadschia argus). Lembeh Strait, North Sulawesi, Indonesia.

Jurgen Freund / Imperial / Emperor shrimp (Periclimenes imperator / Zenopontonia rex) on an Eyed / Leopard sea cucumber (Bohadschia argus). Lembeh Strait, North Sulawesi, Indonesia

Jurgen Freund / Eyed / Leopard sea cucumber (Bohadschia argus), close-up of the skin. Lembeh Strait, North Sulawesi, Indonesia.

Jurgen Freund / Imperial / Emperor shrimps (Periclimenes imperator / Zenopontonia rex) on a sea cucumber. Lembeh Strait, North Sulawesi, Indonesia.

David Shale / Deepsea benthic Sea cucumber (Peniagone sp) with commensal polynoid polychaete, from mid atlantic ridge, depth approx 2600m, June 2010

David Shale / Deepsea benthic Sea cucumber (Peniagone porcella) from mid atlantic ridge, depth approx 2500m, June 2010

David Shale / Underside of deepsea Sea cucumber (Deima validum) from 2500m, mid Atlantic ridge, June 2010

Jeff Rotman / Scarlet Psolus Sea Cucumber (Psolus fabricii), feeding with arm in mouth. Bay of Fundy, Canada, Atlantic Ocean.

Georgette Douwma / Burrowing sea cucumber (Neothyonidium magnum). The massive tentacular crown is the only part that is visible, the rest is buried in the sand. Feeds by picking particles out of the water with the tenta...

Jurgen Freund / Shark fins and Sea cucumbers drying. Philippines.

Magnus Lundgren / Wild Wonders of China / Pineapple sea cucumber (Thelenota ananas) Green Island, Taiwan. Endangered species.

Andy Murch / Happy Eddie (Haploblepharus edwardsii) shyshark amongst Sea slugs (Holothuroidea). False Bay, Western Cape, South Africa. June.

David Fleetham / Sea cucumber (Bohadschia argus) which has ejected a part of its internal organs called Cuvierian tubules. These significantly sticky strings are a defense mechanism designed to deter predators. Yap, M...

Francisco Marquez / Sea cucumber (Holothuria hylla) on white background, Islas Marias Archipelago, Marias Biosphere Reserve, Mexico.

Sirachai Arunrugstitchai / Dried Japanese sea cucumbers (Apostichopus japonicus). This highly prized species can cost over US$3500 per kg. Displayed for sales at a store in Hong Kong Island, 2019.

Sirachai Arunrugstitchai / Graeff's sea cucumbers (Bohadschia graeffei) extend their bodies to spawn on top of coral bommie, releasing gametes into the flowing current at Hin Daeng Pinnacle, Mu Koh Lanta National Park, Krabi Pr...

Sirachai Arunrugstitchai / Graeff's sea cucumbers (Bohadschia graeffei) extend their bodies to spawn on top of coral bommie, releasing gametes into the flowing current at Hin Daeng Pinnacle, Mu Koh Lanta National Park, Krabi Pr...

Shane Gross / Sea cucumber (Holothuroidea) larva amongst Plankton at night. The Bahamas.

Jurgen Freund / Split level of Sea cucumbers (Holothuroidea) on sea floor at low tide, tourist looking at coral reef with coral scope in background. Southern Great Barrier Reef, Heron Island, Queensland, Australia. 2...

Jurgen Freund / Sea cucumber (Holothuroidea) group in coral reef at low tide, split level view. Southern Great Barrier Reef, Heron Island, Queensland, Australia. 2016.

Jurgen Freund / Sea cucumber (Holothuroidea) group and Giant clam (Tridacna sp) in Great Barrier Reef. Queensland, Australia.

David Hall / Armored Sea Cucumber (Psolus chitonoides), Seven Tree Island, Browning Pass, Queen Charlotte Strait, British Columbia, Canada. September .

David Hall / Red sea cucumbers (Cucumaria miniata) and plumose anemones (Metridium farcimen)North Wall, Browning Pass, Queen Charlotte Strait, British Columbia, Canada. September.

David Fleetham / Graeff's sea cucumber (Pearsonothuria graeffei) showing the tentacles of this adult Holothurian feeding. Fiji.

Dimitris Poursanidis / Sea cucumber (Holothuria tubulosa) in seagrass meadow. Skyros, North Aegean, Greece.

Pascal Kobeh / Barrel sponge (Xestospongia testudinaria) covered with Lampert's sea cucumbers (Synaptula lamperti). Crinoids and Feather stars (Crinozoa) also on Sponge. Jewel fairy basslets (Pseudanthias squami...

Georgette Douwma / Kaleidoscopic image of Sea apple (Pseudocolochirus violaceus). Komodo National Park, Indonesia.

Tony Wu / Japanese sea cucumber (Apostichopus japonicus), rare albino. Hokkaido, Japan. May.

Georgette Douwma / Lampert's sea cucumber (Synaptia lamperti) group feeding, North Sulawesi, Indonesia.

Georgette Douwma / Candycane sea cucumber (Thelenota rubralineata). North Sulawesi, Indonesia.

Georgette Douwma / Candycane sea cucumber (Thelenota rubralineata) detail. North Sulawesi, Indonesia.

Magnus Lundgren / Wild Wonders of China / Sea apple, eating, using arm to transfer food into mouth. Ninepin Group or Kwo Chau Islands, Sai Kung District of Hong Kong, China

David Fleetham / Sea cucumber (Holothuria pervicax) at night with Red boring sponge (Hamigera sp) in foreground. Hawaii.

David Fleetham / Imperial shrimp (Periclimenes imperator / Zenopontonia rex), two on Sea cucumber (Holothuroidea). Wakaya, Fiji.

Georgette Douwma / Yellow sea cucumbers (Colochirus robustus) feeding in current. Triton Bay, West Papua, Indonesia.

Magnus Lundgren / Wild Wonders of China / Japanese spiky sea cucumber (Apostichopus japonicus). Bohai Sea, Yellow Sea. Zhifu Island, Shandong Province, China.

Magnus Lundgren / Wild Wonders of China / Japanese spiky sea cucumber (Apostichopus japonicus). Bohai Sea, Yellow Sea. Zhifu Island, Shandong Province, China.

Nick Hawkins / Orange-footed sea cucumber (Cucumaria frondosa) tentacles, Bay of Fundy, New Brunswick, Canada, July.

Linda Pitkin / Leather coral (Sarcophyton sp.), on a rock with soft corals and Yellow Sea Cucumbers (Colochirus robustus), Triton Bay, near Kaimana, West Papua, Indonesia

Franco Banfi / Emperor shrimp (Periclemenes imperator) on sea cucumber (Thelenota ananas) Tubbataha Reef Natural Park, UNESCO World Heritage Site, Sulu Sea, Cagayancillo, Palawan, Philippines

Franco Banfi / Emperor shrimp (Periclemenes imperator) on sea cucumber (Thelenota ananas) Tubbataha Reef Natural Park, UNESCO World Heritage Site, Sulu Sea, Cagayancillo, Palawan, Philippines

Franco Banfi / Emperor shrimp (Periclemenes imperator) on sea cucumber (Thelenota ananas) Tubbataha Reef Natural Park, UNESCO World Heritage Site, Sulu Sea, Cagayancillo, Palawan, Philippines

Franco Banfi / Emperor shrimp (Periclemenes imperator) on sea cucumber (Thelenota ananas) Tubbataha Reef Natural Park, UNESCO World Heritage Site, Sulu Sea, Cagayancillo, Palawan, Philippines

Franco Banfi / Emperor shrimp (Periclemenes imperator) on sea cucumber (Thelenota ananas) Tubbataha Reef Natural Park, UNESCO World Heritage Site, Sulu Sea, Cagayancillo, Palawan, Philippines