Nick Upton / Group of Dog whelks (Nucella lapillus) in an intertidal rock crevice among Acorn barnacles (Balanus perforatus) and Beadlet anemones (Actinia equina), Cornwall, UK, April.

Nick Upton / European oyster drill / Sting winkle (Ocenebra erinacea) a pest of oyster beds, on rocks low on the shore alongside Acorn barnacles (Balanus perforatus) exposed at low tide, with seaweed, rock pools a...

Nick Upton / Common limpets (Patella vulgata) and Acorn barnacles (Balanus perforatus) attached to rocks exposed at low tide, Lyme Regis, Dorset, UK, April.

PREMAPHOTOS / Acorn barnacles on rock (Balanus perforatus) UK

Nick Upton / Acorn barnacles (Balanus perforatus) attached to limestone rocks alongside Common mussels (Mytilus edulis) with barnacles and recently settled cyprid larvae in the process of calcifying on the rock fa...

Nick Upton / Wide angle view of Acorn barnacles (Balanus perforatus) attached to rocks alongside Common mussels (Mytilus edulis) with masses of very young barnacles and recently settled cyprid larvea in the proces...

Nick Upton / Wide angle view of Acorn barnacles (Balanus perforatus) attached to rocks alongside Common mussels (Mytilus edulis) with young barnacles and recently settled cyprid larvea in the process of calcifying...

Nick Upton / Acorn barnacles (Balanus perforatus) living and dead attached to rocks alongside Common mussels (Mytilus edulis) with masses of very young barnacles and recently settled cyprid larvae in the process o...

Nick Upton / Acorn barnacles (Balanus perforatus) filter feeding underwater in a rock pool, Rhossili, Gower Peninsula, Glamorgan, Wales, UK, August.

Nick Upton / Acorn barnacles (Balanus perforatus) filter feeding underwater in a rock pool, Rhossili, Gower Peninsula, Glamorgan, Wales, UK, August.