Alex Hyde / Colony of Common Mussels (Mytilus edulis) growing on striated rock formation exposed at low tide. Cornwall, England, UK. Highly commended in the Coast and Marine Category of the British Wildlife Photo...

David Fleetham / Necklace seastar (Fromia monilis) on Sea cucumber (Bohadaschia argus) Yap, Micronesia.

Juergen Freund / Split level - blue starfish (Linckia laevigata) scattered in the shallow white sands and a nearby mangrove island, Nukubati Island Resort, Macuata Province, Fiji, South Pacific

Emanuele Biggi / Hammerhead worms (Bipalium sp) on leaf, Sarawak. Borneo.

Lynn M. Stone / American oystercatcher (Haematopus palliatus) feeding on Calico Clam, shortly after dawn, seashore, Tampa Bay, St. Petersburg, Florida, USA. April.

Alex Mustard / High magnification photo of the spines of a Common starfish (Asterias rubens). Gulen, Bergen, Norway. North Sea, North East Atlantic Ocean.

Franco Banfi / Emperor shrimp (Periclemenes imperator) on sea cucumber (Thelenota ananas) Tubbataha Reef Natural Park, UNESCO World Heritage Site, Sulu Sea, Cagayancillo, Palawan, Philippines

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

Luis Quinta / Patterns made in sand by Mint-sauce worms (Symsagittifera roscoffensis / Convoluta roscoffensis) sunbathing at low tide to allow the symbiotic algae to photosynthesise. Costa de Caparica beach, Port...

Ernie Janes / Empty Cockle Shells washed up on shore of Solway, Dumfries, Scotland, UK, June.

Michael Hutchinson / Red slug (Arion rufus), Bristol, England, UK, September.

Franco Banfi / California sealion, (Zalophus californianus), playing with seastar, Los Islotes, Sea of Cortez, Baja California, Mexico, East Pacific Ocean