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

Juergen Freund / Imperial / Emperor shrimp (Periclimenes imperator / Zenopontonia rex) on an Eyed / Leopard sea cucumber (Bohadschia argus). Lembeh Strait, 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 / Pacific Sea Apple sea cucumber (Pseudocolochirus violaceus) feeds on passing plankton with feathery mouthparts, Komodo National Park, Indonesia.

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

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

Sue Daly / Sea cucumber (Cucumaria frondosa), Trondheimsfjord, Norway, July.

Linda Pitkin / Sea cucumber / Sea apple (Pseudocolochirus violaceus) Rinca, Komodo National Park, Indonesia.

Franco Banfi / Orange sea cucumber (Cucumaria miniata) Little Strytan dive site, Eyjafjordur nearby to Akureyri, northern Iceland, North Atlantic Ocean.

Scott Leslie / Green Sea Urchin (Strongylocentrotus droebachiensis) barren with Orange-footed Sea Cucumber (Cucumaria frondosa), Passamaquoddy Bay, Maine