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Spiny brittle star

Spiny brittle star

On Exhibit: Monterey Bay Habitats

Animal Facts

  • Scientific Name

    Ophiothrix spiculata

  • Animal Type


  • Diet

    organic particles, small animals

  • Size

    disc to .7 inches across (1.8 cm); arms 5 to 8 times disc size

  • Relatives

    sea stars, sea urchins, sand dollars, sea cucumbers; Phylum: Echinodermata

  • Habitat

    Sandy Seafloor

  • Range

    Northern California to Peru; also Galapagos Islands

Natural History

Brittle stars are sea star cousins that bury themselves for protection, leaving an arm or two free to catch bits of food. Sometimes this attracts a hungry fish but fortunately, a star can't be tugged out by the arm. The arm snaps off, and a new one grows from the stump. At night, they stretch out to catch food particles, passing the bits down to the central mouth.


Used motor oil poured down the drain or on the ground winds up in rivers, lakes, and the ocean. No matter what the source, oil harms ocean animals. Each year, Americans illegally dispose of 220 million gallons of oil—twenty times the Exxon Valdez spill. The solution? Recycle the oil—it can be re-refined and reused.

Cool Facts

Brittle stars occur in incredible numbers on the sandy seafloor. In kelp forests near La Jolla in southern California, millions of them may carpet the seafloor in layers up to an inch thick! 

Brittle stars live in a wide range of water depths—from the shoreline down to 6,755 feet (2,059 m).

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