Alex Mustard / A diver exploring a coral reef with formation of brown tube sponges (Agelas conifera) red rope sponges (Amphimedon compressa) and deepwater sea fans (Iciligorgia nodulifera) East End, Grand Cayman, Ca...

Jeff Rotman / Gorgonian Seafan Coral (Gorgonacea) polyps open to feed at night. South China Sea, Sipadan Island, Borneo.

Juergen Freund / Fan coral (Gorgonacea) with open polyps. Misool, Raja Ampat, West Papua, Indonesia..

Juergen Freund / Split-level shot of Fan coral (Gorgonacea) in the shallows with boat shilouetted against the sunset in the background. North Raja Ampat, West Papua, Indonesia, February 2010

Tim Laman / Denise's Pygmy seahorse (Hippocampus denise) camouflaging itself in a Sea Fan. Yellow colour form. Pisang Islands, West of Fak Fak Peninsula. West Papua, Indonesia, April 2007

Juergen Freund / Orange elephant ear sponge (Agelas clathrodes), with other sponges and gorgonians, Indo-pacific

Chris Newbert / Reef scenic at one-hundred-twenty feet, showing Soft Corals, Sea Fans, Crinoids, Leather Corals, Sea Whips and Sponges, Solomon Islands

Fred Bavendam / Butterfly Perch (Caesioperca lepidoptera) swimming amidst Gorgonian Sea Whips, fans and various kinds of sponges at 40 meters depth, Tasman Peninsula, Tasmania, Australia

Fred Bavendam / Butterfly Perch (Caesioperca lepidoptera) and diver swimming amidst Gorgonian Sea Whips, Fans and various kinds of Sponges at 40 meters depth, Tasman Peninsula, Tasmania, Australia

Juergen Freund / Gorgonian fan corals, Raja Ampat, West Papua, Indonesia

Juergen Freund / Gorgonian fan corals in Raja Ampat coral reef, near to mangroves, Raja Ampat, West Papua, Indonesia

Juergen Freund / Gorgonian fan corals (Gorgonacea) split level with mangroves, Raja Ampat, West Papua, Indonesia