Giant Spined Sea Star
Pisaster giganteus

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 their 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 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

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