Sue Daly / Cushion Star (Asterina gibbosa) on sea shore, Sark, British Channel Islands.

MYN / Carsten Krieger / Cushion Star (Asterina gibbosa) from rock pool, County Clare, Republic of Ireland, August. Meetyourneighbours.net project

Michele Westmorland / Panamic Cushion Sea Star (Pentaceraster cumingi) on reef structure. Galapagos Islands.

Michele Westmorland / Diver swimming over reef structure. Panamic Cushion Sea Star (Pentaceraster cumingi) Galapagos Islands.

Alex Mustard / Cushion star (Asterina pancerii), juvenile backlit through a blade of seagrass (Posidonia oceanica). Punto Saline, Olbia, Sardinia, Italy. Tyrrhenian Sea, Mediterranean Sea. Endangered species.

Nick Upton / Cushion star (Asterina gibbosa) exposed on a low spring tide on rocks among barnacles (Verruca stroemia) and holdfasts of Tangleweed kelp (Laminaria digitata), near Falmouth, Cornwall, UK, August.

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 / Cushion star (Asterina gibbosa) in rockpool alongside Common limpet (Patella vulgata) and red algae, Wembury, Devon, UK, August.

Alex Mustard / Cushion sea star (Oreaster reticulatus) high magnification detail of the skin gills used to absorb oxygen from the water between the red knobbly spines, East End, Grand Cayman, Cayman Islands, British...

Alex Mustard / Cushion sea star (Oleaster reticulatus) on turtle grass (Thalassia testudinum) below man standing on a jetty, East End, Grand Cayman, Cayman Islands, British West Indies. Caribbean Sea.

Juergen Freund / Skin detail of Pin cushion sea star (Culcita novaguineae) West New Britain, Papua New Guinea.

Juergen Freund / Star shaped Pincushion / Pillow cushion starfish (Culcita novaeguinea), detail of the underbelly. Lembeh Strait, North Sulawesi, Indonesia.