Plectaster decanus Muller and Troschel 1843
mosaic sea star, carpet star
Plectaster decanus, mosaic sea star,  carpet star

family Echinasteridae

The Mosaic Seastar or Carpet Star, Plectaster decanus, has five arms. Rows of granules form a network of ridges, clusters purple or red papules fill the spaces in between. The insert in the picture shows the detail of the tube feet.

Distribution =   southern Australia, Two Rocks WA to Byron Bay and northern Tas.
Max size =   arm radius to 12cms