Shane Gross / Bubble coral shrimp (Vir philippinensis) on Bubble coral (Plerogyra sp). Anilao, Philippines.

David Fleetham / Bubble coral shrimp (Vir philippinensis) on Bubble coral (Plerogyra sp), Philippines.

Pascal Kobeh / Divers are setting up concrete reef balls to build an artificial reef, Philippines, Sulu Sea. August 2014.

Alex Mustard / Diver blowing bubble rings, while resting on the sand, East End, Grand Cayman, Cayman Islands, British West Indies, Caribbean Sea, January 2011.

Jeff Rotman / Free diver coming up from dive to explore coral reef, Sinai, Egypt, Red Sea Model released Model released.

Pascal Kobeh / Bubble-coral (Plerogyra sp.) New Caledonia, Pacific Ocean.

Pascal Kobeh / Coleman's bubble coral shrimp (Vir colemani) with its eggs in a bubble-coral (Plerogyra sinuoasa) where it is protected, New Caledonia, Pacific Ocean Completed Review

Gary Bell/ Oceanwide / Hard Tube Coco Worm (Protula magnifica) filter feeding in Euphyllia Coral (Euphyllia ancora), Great Barrier Reef, Australia

Georgette Douwma / Kaleidoscopic image of Bubble tip anemone (Entacmaea quadricolor). Raja Ampat, West Papua, Indonesia.

Georgette Douwma / Kaleidoscopic image of Bubble tip anemone (Entacmaea quadricolor). Raja Ampat, West Papua, Indonesia.

David Fleetham / Orang utan crab (Achaeus japonicus), with its red algae growth, on bubble coral, Philippines.

Franco Banfi / Rounded bubblegum / Bubble coral (Plerogyra sinuosa) with two Gobies (Gobiidae) on it, Lazi Pier, Dumaguete, East Negros Island, Central Visayas, Philippines, Pacific Ocean.