Jordi Chias / Sponge (Mycale acerata) with diver. Lermaire strait, Antarctic Peninsula, Antarctica.

Nick Upton / Mourtia beach and bay with the southeast tip of Samos and Mount Mycale in Turkey's Dilek Peninsula National Park in the background, east coast of Samos, August 2011.

Norbert Wu / Sponge (Mycale acerata) and kelp forest, Palmer Station, Antarctic Peninsula, Antarctica

Norbert Wu / Antarctic Sun Starfish (Labidiaster annulatus), Hydrozoan (Candelabrum penola), and Sponge (Mycale acerata) below kelp forest, Palmer Station, Antarctic Peninsula, Antarctica

Nick Upton / Mikri Laka beach with the southeast tip of Samos and Mount Mycale in Turkey's Dilek Peninsula National Park in the background, east coast of Samos, August 2011.

Nick Upton / Mourtia beach and bay with the southeast tip of Samos and Mount Mycale in Turkey's Dilek Peninsula National Park in the background, east coast of Samos, August 2011.

Juergen Freund / Orange icing sponge {Mycale laevis} on brain coral. Caribbean.

Alex Mustard / Orange icing sponge (Mycale laevis) growing on Mountainous star coral (Orbicella faveolata) at an early stage of growth, Cayman Islands, Caribbean Sea.

Shane Gross / Close up of Spiny pink scallop (Chlamys hastata) showing eye detail and Smooth scallop sponge (Mycale adhaerens) encrused on top of shell, Vancouver Island, British Columbia, Canada, Pacific Ocean.

Alex Mustard / Sponge spider crab / Decorator crab (Inachus sp) on Sea vases (Ciona intstinalis). Kinlochbervie, Sutherland, The Highlands, Scotland, United Kingdom. Loch Inchard, The Minch, North East Atlantic Ocea...

Alex Mustard / Sponge spider crab / Decorator crab (Inachus sp) clambers over Sea vases (Ciona intstinalis). Kinlochbervie, Sutherland, The Highlands, Scotland, United Kingdom. Loch Inchard, The Minch, North East At...

Claudio Contreras / Orange icing sponge (Mycale laevis), Guanahacabibes Peninsula National Park, Pinar del Rio Province, western Cuba.