Week #4: Giant Spined Sea Star, Pisaster giganteus

img_8716 Photo by Dana Roeber Murray

I am one of the ocean’s most fascinating creatures and can only be found in marine environments. I am a member of phylum Echinodermata (Ancient Greek: echinos – “hedgehog” derma – “skin”) and we are special in that we are not found in freshwater or terrestrial environments. Like my brothers and sisters, I also possess the unique ability to regenerate my spiny limbs lost to predators like seagulls and can detach my arms to act as a distraction while I make my escape. If I am cut in half, I have the ability to grow into 2 new starfish—pretty cool! When I’m not avoiding predators I’m on the lookout for my next meal, which generally consists of barnacles, snails, mussels, limpets, and pretty much anything else I can find. I feed a bit differently that other organisms, which in my case means that I can extend my stomach out into tiny cracks in my prey’s shell and digest the soft tissue found inside.

Why should humans care about me?

Sea stars are negatively affected by pollution and disease, sometimes being used as an indicator for the quality of ocean water around our home. Many scientists have also labeled me as a keystone species, which means that if I were gone, the delicate relationships in the intertidal ecosystem would be thrown into chaos. I help keep the populations of my prey at a manageable level, making sure that none of them can dominate the community and outcompete other species. In fact, studies in the past have found that if sea stars are removed from a shoreline, the overall number of different species in that area will decrease drastically, which is also bad news for humans who live nearby and want to go snorkeling, tide pooling, or enjoy eating seafood. Us sea stars know these things are important to many people in San Diego, so please help take care of the water I live in and use best practices when exploring tide pools!  

If you would like to help in the conservation of my species there are ample volunteer opportunities with WILDCOAST to help clean up beaches and collect data on Marine Protected Areas in San Diego County. Contact cory@wildcoast.net for more info on how to get involved.  


Giant Spined Sea Star
Pisaster giganteus

10974366_633782676748762_2214133538759859893_oHere I am with my friend the California Spiny Lobster (Panulirus interruptus). Photo by Dana Roeber Murray