Sue Daly / Close-up of a Seven rayed starfish (Luidia ciliaris) moving over the seabed, showing use of its tube feet to walk, Sark, British Channel Islands, UK, August.

Sue Daly / Seven rayed starfish (Luidia ciliaris) moving over the seabed, showing use of its tube feet to walk, Sark, British Channel Islands, UK, August.

SCOTLAND: The Big Picture / Seven armed starfish (Luidia ciliaris) semi buried in the seabed, South Arran Marine Protected Area, Isle of Arran, Scotland, UK, August.

SCOTLAND: The Big Picture / Seven armed starfish (Luidia ciliaris) amongst kelp in no take zone, South Arran Marine Protected Area, Isle of Arran, Scotland, UK, August.

Hanne & Jens Eriksen / Comb sea star (Astropecten polyacanthus) in shallow water, Oman, August

Hanne & Jens Eriksen / Comb sea star (Astropecten polyacanthus) digging itself into the sand, Oman, August

Hanne & Jens Eriksen / Starfish (Luidia savignyi) upperside, in shallow water on beach, Oman, December

Sue Daly / Seven Armed Starfish (Luidia ciliaris) Boue Tirlipois, Sark, British Channel Islands.

Tui De Roy / Starfish (Luidia bellonae) in cold algal community at heart of Cromwell Current upwelling. Fernandina Island coast, Galapagos Islands, Ecuador. Pacific Ocean.

Tui De Roy / Starfish (Luidia bellonae) in cold algal community at heart of Cromwell Current upwelling. Fernandina Island coast, Galapagos Islands, Ecuador. Pacific Ocean.

Joel Sartore / Photo Ark / Two Gray sand stars, showing varying color morphs. (Luidia lawrencei) the larger, solid colored starfish on the left and (Luidia clatherata) the smaller starfish with lines, on white background, Gulf...

Joel Sartore / Photo Ark / Two Gray sand stars, showing varying color morphs. (Luidia lawrencei) the larger, solid colored starfish on the left and (Luidia clatherata) the smaller starfish with lines, on black background, Gulf...