Group of American slipper limpets (Crepidula fornicata), invasive pests of oyster beds in Europe, stacked on top of one another on mudflats near barnacle encrusted Common mussels (Mytilus edulis) with moored sailing yachts in the background, Helford River, Helford, Cornwall, UK, August.

- Image ID: W7N9FX

Group of American slipper limpets (Crepidula fornicata), invasive pests of oyster beds in Europe, stacked on top of one another on mudflats near barnacle encrusted Common mussels (Mytilus edulis) with moored sailing yachts in the background, Helford River, Helford, Cornwall, UK, August.

Nature Picture Library / Alamy Stock Photo

Image ID: W7N9FX