Physical Description

  • Large, five-pointed sea star.
  • Red, brown, tan, or purple coloring.
  • Light blue circles around base of each white spine.
  • 14-19 inches in diameter.
  • Sexes look identical.


  • British Columbia to southern California.


  • Live in low and subtidal regions.
  • Mostly found in protected coastal areas.
  • Found on pier pilings, sand, and rocks.


  • They reproduce by broadcast spawning (releasing sperm and eggs into the water column).
  • Spawning season is March-April.
  • Larvae start life bilaterally symmetric (meaning there is one line where they can be divided into a mirror image) and then settle into adult form as pentaradially symmetric (there are five lines where they can be divided into a mirror image).


  • Barnacles, snails, mussels, limpets, ornate tubeworms, California piddock bivalve.


  • Sheep crab, sea gulls, sea otters.

Interesting Facts

  • They can detach a limb to escape a predator and can regrow that limb later. If they are cut in half, they can grow into two sea stars!
  • Sea stars are considered keystone species, because if they are removed from an ecosystem, the entire ecosystem can end up out of balance, with certain species taking over and out-dominating other species. 
  • The giant spined sea star can be trained to associate a light stimulus with food.

Sources: Wildcoast; Encyclopedia of Life;; UC Irvine Biology; SIMoN

Photo: David R. Andrew