Nick Upton / Velvet swimming crab (Necora puber) in a rock pool, hiding among Coralweed (Corallina officinalis), Cornwall, UK, March.

Nick Upton / Strawberry anemone (Actinia fragracea) in a rock pool alongside Coralweed (Corallina officinalis), Cornwall, UK, March.

Nick Upton / Common shore crab (Carcinus maenas) hiding among Coralweed (Corallina officinalis) in a rock pool, Cornwall, UK, March.

Nick Upton / Coralweed (Corallina officinalis) from Atlantic Ocean. Cornwall, England, UK. September.

Philippe Clement / Common Coral Weed / Coralweed (Corallina officinalis) washed ashore on beach, Normandy, France. September

Nick Upton / Female Common spider crab (Maja brachydactyla / Maja squinado) well camouflaged in a rockpool among Coralweed (Corallina officinalis), Rhossili, The Gower Peninsula, UK, June.

Nick Upton / Snakelocks anemone (Anemonia viridis) among Coralweed (Corallina officinalis) ejecting remains of its prey, a mussel shell. Rhossili, The Gower Peninsula, July.

Nick Upton / Snakelocks anemone (Anemonia viridis) attached to a boulder alongside Coralweed (Corallina officinalis) and Flat / Purple top shells (Gibbula umbilicalis) in a rockpool, Rhossili, The Gower Peninsula,...

Nick Upton / Shore crab (Carcinus maenas) in defensive posture with claws raised in crevice under Coralweed (Corralina officinalis). Rhossili, The Gower Peninsula, UK, July.

Nick Upton / Sea lettuce / Green laver (Ulva lactuca) growing in a rockpool alongside Coralweed (Corallina officinalis). Rhossili, The Gower Peninsula, UK, July.

Nick Upton / Sea lettuce / Green laver (Ulva lactuca) growing in a rockpool alongside Coralweed (Corallina officinalis). Rhossili, The Gower Peninsula, UK, July.

Nick Upton / Yolk and developing embryo visible in Mermaid's purse egg case of Lesser spotted catshark / Dogfish (Scyliorhinus canicula) entangled with Coralweed (Corallina officinalis) in a rockpool. Rhossil...

Nick Upton / Yolk and developing embryo visible in Mermaid's purse egg case of Lesser spotted catshark / Dogfish (Scyliorhinus canicula) entangled with Coralweed (Corallina officinalis) in a rockpool. Rhossil...

Nick Upton / Yolk and developing embryo visible in Mermaid's purse egg case of Lesser spotted catshark / Dogfish (Scyliorhinus canicula) entangled with Coralweed (Corallina officinalis) in a rockpool. Rhossil...

Nick Upton / Spiny starfish (Marthasterias glacialis) among Coralweed (Corallina officinalis), Wembury, Devon, UK, August.

Nick Upton / Brown seaweed (Bifurcaria bifurcata), an alga that has shown some anti-cancer properties, growing in a rockpool low on the shore alongside Coralweed (Corallina officinalis), Wembury, Devon, UK, August...

Nick Upton / Broad-clawed porcelain crab (Porcellana platycheles) well camouflaged among Coralweed (Corallina officinalis) and encrusting red algae (Lithothamnion sp.) in a rockpool low on the shore, near Falmouth...

Nick Upton / Common brittle star (Ophiothrix fragilis) well camouflaged among mix of red and green algae including Coralweed (Corallina officinalis), Harpoon weed (Asparagopsis armata) and Sea lettuce (Ulva lactuc...

Nick Upton / Cushion star (Asterina gibbosa) on the move over submerged rocks low on the shore among a mix of red algae including Coralweed (Corallina officinalis) and Sea horsetail (Halurus equisetifolus) submerg...

Nick Upton / Red hornweed (Ceramium virgatum) growing in a rockpool low on the shore alongside Coralweed (Corallina officinalis) and Sea lettuce (Ulva lactuca), Wembury, Devon, UK, August.

Nick Upton / Brown seaweed (Bifurcaria bifurcata), an alga that has shown some anti-cancer properties, growing in a rockpool low on the shore alongside Coralweed (Corallina officinalis), Wembury, Devon, UK, August...

Nick Upton / Common Blenny / Shanny (Lipophrys pholis) hiding under Coralweed (Corallina officinalis) in a rockpool near a Common / Edible periwinkle (Littorina liitorea), Rhossili, The Gower peninsula, UK, July.

Nick Upton / Common Blenny / Shanny (Lipophrys pholis) hiding under Coralweed (Corallina officinalis) in a rockpool near a Common / Edible periwinkle (Littorina liitorea), Rhossili, The Gower peninsula, UK, July.

Nick Upton / Colourful mix of Bushy rainbow wrack (Cystoseira tamariscifolia) with turquoise iridescent tips to its fronds and red Harpoon weed (Asparagopsis armata) surrounded by Coralweed (Corallina officinalis)...

Nick Upton / Colourful mix of Bushy rainbow wrack (Cystoseira tamariscifolia) with blue iridescent tips to its fronds and red Harpoon weed (Asparagopsis armata) surrounded by Coralweed (Corallina officinalis) Furb...

Nick Upton / Dense gathering of Common periwinkles (Littorina liitorea) of all ages in a rockpool lined with Coralweed (Corallina officinalis) and Irish moss (Chondrus crispus), North Berwick, East Lothian, July

Nick Upton / Close up of Snakelocks anemone (Anemonia viridis) among Coralweed (Corallina officinalis) filter feeding in a rockpool. Rhossili, The Gower Peninsula, July.

Nick Upton / Shore crab (Carcinus maenas) camouflaged as it hides in a crevice below Coralweed (Corralina officinalis) in a rockpool. Rhossili, The Gower Peninsula, UK, July.

Nick Upton / Common prawn (Palaemon serratus) swimming in a rockpool among Coralweed (Corralina officinalis) and Sea Lettuce / Sea Laver (Ulva lactuca). Rhossili, The Gower Peninsula, UK, July.

Nick Upton / Split level view of Irish moss / Carrageen (Chondrus crispus) iridescing in a sunlit rockpool alongside Coralweed (Corallina officinalis) and Sea Lettuce / Green laver (Ulva lactuca). Rhossili, The Go...

Nick Upton / Edible crab (Cancer pagurus) camouflaged among Coralweed (Corralina officinalis) in rockpool. Rhossili, The Gower Peninsula, UK, July.

Nick Upton / Edible crab (Cancer pagurus) camouflaged among Coralweed (Corralina officinalis) in rockpool. Rhossili, The Gower Peninsula, UK, July.

Nick Upton / Edible crab (Cancer pagurus) camouflaged among Coralweed (Corralina officinalis) in rockpool. Rhossili, The Gower Peninsula, UK, July.

Nick Upton / Lesser spotted catshark / Dogfish (Scyliorhinus canicula) resting on floor of a rockpool among Coralweed (Corallina officinalis) and Irish moss / Carrageen (Chondrus crispus). Rhossili, The Gower peni...

Nick Upton / Close up of Lesser spotted catshark / Dogfish (Scyliorhinus canicula) resting on floor of a rockpool among Irish moss / Carrageen (Chondrus crispus) and Coralweed (Corallina officinalis). Rhossili, Th...

Nick Upton / Close up of Lesser spotted catshark / Dogfish (Scyliorhinus canicula) resting on floor of a rockpool among Coralweed (Corallina officinalis) low on the shore. Rhossili, The Gower peninsula, UK, July.

Nick Upton / Lesser spotted catshark / Dogfish (Scyliorhinus canicula) hiding in a rockpool among Coralweed (Corallina officinalis) and Irish moss / Carrageen (Chondrus crispus). Rhossili, The Gower peninsula, UK,...

Nick Upton / Worm pipefish (Nerophis lumbriciformis) well camouflaged among red and green algae including Coralweed (Corallina officinalis) and Sea lettuce (Ulva lactuca), near Falmouth, Cornwall, UK, August.

Nick Upton / European oyster drill / Sting winkle (Ocenebra erinacea) a pest of oyster beds, on the move over Coralweed (Corallina officinalis) in a low shore rockpool, near Falmouth, Cornwall, UK, August.

Nick Upton / Bulbous holdfast and divided frond of Furbellows (Saccorhiza polyschides), a large kelp, attached to floor of a rockpool alongside red algae: Harpoon weed (Asparagopsis armata) and Coralweed (Corallin...

Nick Upton / Arctic / Northern Cowrie (Trivia arctica) on subtidal rock encrusted with Coralweed (Corallina officinalis). Wembury, Devon, UK, August.