Doug Perrine / Giant brain coral provides shelter for Grunts and Squirrelfish, Florida Keys, USA.

Alex Mustard / Secretary blenny (Acanthemblemaria maria) peering out of a boulder brain coral (Colpophyllia natans) East End, Grand Cayman, Cayman Islands, British West Indies, Caribbean Sea.

Alex Mustard / Secretary blenny (Acanthemblemaria maria) peeking out of a boulder brain coral (Colpophyllia natans) East End, Grand Cayman, Cayman Islands, British West Indies, Caribbean Sea.

Alex Mustard / Brain coral (Colpophyllia natans) showing healthy coral, unmanipulated image. East End, Grand Cayman, Cayman Islands. British West Indies. Caribbean Sea.

Alex Mustard / Brain coral (Colpophyllia natans) probably suffering from white band disease, East End, Grand Cayman, Cayman Islands. British West Indies, Caribbean Sea, January 2010.

Alex Mustard / Brain coral (Colpophyllia natans) bleached, polyps have expelled their zooxanthellae symbiotic algae from their tissue, probably as a result of being stressed by a rise in sea temperature, East End,...

Alex Mustard / Secretary blenny (Acanthemblemaria maria) living in a tube within Boulder brain coral (Colpophyllia natans). Photo illuminated with a single flash, with restricted beam to create hard lighting. East E...

Pete Oxford / Boulder Brain Coral (Colpophyllia natans), Belize Barrier Reef, Belize

Claudio Contreras / Boulder brain coral (Colpophyllia natans) close-up, Banco Chinchorro Biosphere Reserve, Caribbean Sea, Mexico, May

Martha Holmes / Close up of patterns in Brain coral (Colpophyllia natans) Carriacou, Caribbean

Norbert Wu / Boulder Brain Coral (Colpophyllia natans) common in south Florida, Bahamas and Caribbean, Saba, Dutch Antilles

Martha Holmes / Brain coral {Colpophyllia natans} feeding at night polyps exted Dominica Caribbean