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...

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

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

Juergen Freund / Red-Lined Sea Cucumber (Thelenota rubralineata) Raja Ampat, West Papua, Indonesia

Georgette Douwma / Sea cucumber (Synaptula sp.) crawling on (Thelenota rubralineata) Manado, North Sulawesi, Indonesia

Sue Daly / Diver observing Sea cucumber (Thelenota rubralineata) Cebu, Philippines, March 2008. Model released.

Sue Daly / Sea cucumber (Thelenota rubralineata) Cebu, Philippines, March

GEORGETTE DOUWMA / Red-lined sea cucumber (Thelenota rubralineata) Papua New Guinea

GEORGETTE DOUWMA / Red-lined sea cucumber (Thelenota rubralineata) Papua New Guinea

GEORGETTE DOUWMA / Sea cucumber (Thelenota rubralineata). Milne Pay, New Guinea.

Fred Bavendam / Red-lined Sea Cucumber (Thelenota rubralineata) portrait, New Britain Island, Papua New Guinea

Georgette Douwma / Composite image of echinoderms on black background. Top row from left: Featherstar (Crinoidea), Luzon starfish (Echinaster luzonicus), Mosaic cushion star (Halityle regularis). -Central row from...