Physical Description

  • Five-armed sea star, with thin arms and a small radial disc.
  • Red and gray mottled coloration.
  • The normal number of limbs is five, but can have anywhere from one to nine.
  • Arms are often not symmetrical, due to ability to regrow new arms and discs.
  • Maximum size is 4 inches in diameter.


  • Southern California to Peru.
  • Ecuador (Galapagos Islands).
  • May also be present in Hawaii.


  • Lives in the rocky intertidal.
  • Found at depths of 0 to 500 feet.


  • Embryos hatch into biradially symmetric (foldable on one line of symmetry) planktonic larvae that later transform into pentaradially symmetric (foldable on five lines of symmetry) juveniles with stubby arms.


  • Sea stars eat mollusks and detritus.


  • Fragile sea stars are considered rather inedible, although sea stars can be eaten by seabirds, fish, crabs, otters, and even other sea stars. 

Interesting Facts

  • The fragile star is known to undergo autotomy, or self-amputation, where one arm detaches itself from the disc. That arm then regrows a new disc and new arms, a process that can take six months or more to complete. This is often why fragile stars look asymmetrical – they are in the process of regrowing their bodies! 

Sources:; Reef Life Survey; Between Pacific Tides: Fifth Edition; National Aquarium; Benthic Invertebrates of Four Southern California Marine Habitats;

Photo: Matthew Meier