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 main picture shows the detail of the tube feet.
The images below illustrate the colour range of Plectaster decanus.
Distribution = southern Australia, Two Rocks WA to Byron Bay and northern Tas.