D. Parer & E. Parer-Cook / Common Wombat (Vombatus ursinus) with sarcoptic skin mange, which will eventually kill it, southeastern Australia

Georgette Douwma / Cock's comb oyster (Lopha cristagalli) covered with encrusting sponge on artificial reef. Mabul, Malaysia.

Magnus Lundgren / Wild Wonders of China / Barnacles and oysters on mangrove in Ha Pak Nai, a mudflat in the Yuen Long District, Hong Kong, China.

Loic Poidevin / Rows of racks used in oyster farming at high tide, Isle de Re, Charente-Maritime, France, July 2017.

Loic Poidevin / Rows of racks used in oyster farming at low tide, Ie de Re, Charente-Maritime, France, July 2017.

Sue Daly / Pacific oyster (Magallana gigas) farm, Herm, British Channel Islands, June 2016

Nick Upton / Pacific oyster / Japanese oyster / Miyagi oyster (Crassostrea gigas) attached to rocks among barnacles, mussels, limpets and anemones, exposed at low tide, Asturias, Spain, August

Philippe Clement / Cultivated oysters (Lophia folium) in bags at oyster farm / oyster park exposed on beach at low tide, Saint-Martin-de-Varreville, Normandy, France, June 2015

Benjamin Barthelemy / Aerial view of oyster hatcheries in Le Banc d'Arguin, Arcachon Bay, Aquitaine, France, June 2014.

Georgette Douwma / Cock's comb oyster (Lopha cristagalli) covered with encrusting sponge on artificial reef. Mabul, Malaysia.

Philippe Clement / Oyster (Ostreidae), barnacles and limpets growing on rock exposed on beach at low tide. Brittany, France, September.

Philippe Clement / Oyster (Ostreidae), barnacles and mussels (Mytillus) growing on rock exposed on beach at low tide. Brittany, France, September.

Ingo Arndt / Giant Pacific Oyster (Crassostrea gigas) colony, invasive species oppresses local Mussel (Mytilus edulis), Sylt Island, North Sea, Germany

Ingo Arndt / Giant Pacific Oyster (Crassostrea gigas) colony, invasive species oppresses local Mussel (Mytilus edulis), Sylt Island, North Sea, Germany

Ingo Arndt / Giant Pacific Oyster (Crassostrea gigas) colony, invasive species oppresses local Mussel (Mytilus edulis), Sylt Island, North Sea, Germany

Philippe Clement / Japanese Oyster / Pacific Oyster shell (Crassostrea gigas), North Sea, Belgium

Flip de Nooyer / Long-eared Owl (Asio otus) two owlets, Europe

Flip de Nooyer / Long-eared Owl (Asio otus) three owlets on branch, Europe

Tim Fitzharris / Long-eared Owl (Asio otus) perched in tree, circumpolar species, British Columbia, Canada

Tim Fitzharris / Long-eared Owl (Asio otus) perching in a tree, circumpolar species, British Columbia, Canada

Konrad Wothe / Long-eared Owl (Asio otus), Europe

Konrad Wothe / Long-eared Owl (Asio otus), Europe

Peter Scoones / Oysters covered with encrusting sponge {Ostreidae} Andaman sea, Thailand

Ashley Cooper / Oyster (Ostreidae) shells from a fish farm, Walney island, Cumbria, UK. March.

Joel Sartore / Photo Ark / Encrusting sand tube worm (Sabellaria sp.) and Ivory barnacles (Balanus eburneus) on the shell of a American / Common oyster (Crassostrea virginica), Gulf Specimen Marine Lab and Aquarium.

Joel Sartore / Photo Ark / Encrusting sand tube worm (Sabellaria sp.) and Ivory barnacles (Balanus eburneus) on the shell of a North America / Common oyster (Crassostrea virginica), Gulf Specimen Marine Lab and Aquarium.

Magnus Lundgren / Zig zag oyster (Lopha folium), close up, Triton Bay, West Papua, Indonesia, Pacific Ocean.

David Fleetham / Zigzag oyster (Lopha cristagalli) also known as the Cock's comb oyster, Yap, Federated States of Micronesia. As is often the case, this individual is covered in an encrusting sponge.

Chris Shields / Illustration of Common oyster (Ostrea edulis)