A sacoglossan sea slug beside its spiralling (Archimedean) egg ribbon

Bobtail Squid with its flamboyant, communicative mantle on display

Lined Chiton, its shell made of eight overlapping plates

A gaping Giant Clam

A Spondylus thorny oyster

An Aztec double–headed serpent made of turquoise, red Spondylus and white conch shell, probably part of a sixteenth–century ceremonial costume

A Little Egg Cowrie

Mask made from a large Spondylus shell in Manabi, Ecuador between 800 and 400 BC

Andy Woolmer pouring oysters into the sea off the Mumbles in Swansea Bay, Wales

A handful of Native Oysters ready to go back to the seabed

A Striped Hermit Crab. It has made a Calliostoma top shell its home, with a fringe of stinging hydroids clinging to the outside

Fatou Janha cheers on wrestlers at the Gambian Oyster Festival

An Oyster festival costume

A midden of Gambian oyster shells

A member of the TRY Oyster Women's Association shucks oysters

Celebrations at the festival

Triton shells from the Conchologia Iconia, drawn by Lovell Reeve and based on shells at the Cuming Museum, 1843

Blue-ray Limpets, clustered on a kelp frond

The teeth of a Common Limpet seen under an electron microscope. These teeth are made of the strongest biological material known — all the better for scraping the limpet's algal food from rocks

A chambered nautilus, swimming in the sea off the island of Palau in Micronesia

A Janthina snail floats at the surface on a raft of bubbles, camouflaged against the open ocean by its blue shell and foot

A Veined Octopus peers from the bivalve shell that it uses as a hideaway

A female argonaut peeps from her shell, which she uses as a portable chamber to brood her young and control her buoyancy

A clutch of baby argonauts, each around 1mm long

Raw byssus from a single Noble Pen Shell

Sea-silk embroidery by Assuntina and Giuseppina Pes

Ignazio Marrocu demonstrates a tool that was once used to harvest pen shells, at the Museo Etnografico in Sant'Antioco

A Noble Pen Shell, standing high above the Mediterranean sea bed

Sea–silk weaver Efisia Murroni

Newly discovered micromolluscs from islands off Papua New Guinea, found by Philippe Bouchet and his team

KOSMOS mesocosms in Gran Canaria, used to study the effects of increasing acidity on open ocean ecosystems

A sea butterfly with its tiny wings and left-coiling shell

A sea angel — not as angelic as it appears. This shell-less swimming gastropod is a deadly enemy of the sea butterfly