GEORGETTE DOUWMA / Carrier / Dorippid crab (Dorippe frascone) on sea bed holding Sea urchin (Astropyga radiata) on its shell, Lembeh Strait, North Sulawesi, Indonesia.

GEORGETTE DOUWMA / Carrier / Dorippid crab (Dorippe frascone) on sea bed holding Sea urchin (Astropyga radiata) on its shell, Lembeh Strait, North Sulawesi, Indonesia.

Chris Newbert / Coleman's Shrimp (Periclimenes colemani) and Adam's Urchin Crab (Zebrida adamsii) on Fire Urchin (Asthenosoma varium), Indonesia

GEORGETTE DOUWMA / Radiant sea urchin {Astropyga radiata} carried on the back of a Dorippid crab (Dorippe frascone). Lembeh Strait, North Sulawesi, Indonesia.

Georgette Douwma / Adam's urchin crab (Zebrida adamsii) on Fire urchin (Asthonosoma varium), Rinca, Indonesia

Georgette Douwma / Adam's urchin crab (Zebrida adamsii) on Fire urchin (Asthenosoma varium), Rinca, Indonesia

Georgette Douwma / Two Adam's urchin crabs (Zebrida adamsii) on Fire urchin (Asthonosoma varium), Rinca, Indonesia

Konrad Wothe / Sally Lightfoot Crab (Grapsus grapsus) spraying near sea urchin, Galapagos Islands, Ecuador

Constantinos Petrinos / Adam's urchin crab {Zebrida adamsii} on sea urchin {Astropyga radiata} Indonesia, Sulawesi

Constantinos Petrinos / Sea urchin {Astropyga radiata} on crab, Sulawesi, Indonesia

Gary Bell/ Oceanwide / Adam's Urchin Crab (Zebrida adamsii) pair on Fire Urchins (Asthenosoma varium), Lembeh Strait, Indonesia

Tui De Roy / Flightless Cormorant (Phalacrocorax harrisi) carrying Pencil-spined Sea Urchin (Eucidaris thouarsii) prey near Sally Lightfoot Crabs (Grapsus grapsus), Punta Albemarle, Isabela Island, Galapagos Islan...