Piaster giganteus can be found in both very low intertidal to depths of 90 m (1), though subtidal specimens are larger than intertidal specimens (4). Giant sea stars can be up to 56 cm in diameter and normally have five arms, though some have been found with six arms (1). Their bodies can be yellow, orange, brown or purple and are completely covered with calcium carbonate spines (1)(4). P. giganteus’ spines are long and blue, ending in a white tip (1). Like most sea stars P. giganteus are carnivorous scavengers that prey upon a wide variety of organisms (4), preferentially feeding on mussels (1). They are severely affect by sea star wasting disease, which leads to behavioral changes, loss of limbs, and ultimately death (3), with several observations found on Coal Oil Point (2).
(1) Gotshall, D. W. (2005). Guide to marine invertebrates: Alaska to Baja California. Monterey, CA: Sea Challengers.
(2) Hewson, Ian, Jason B. Button, Brent M. Gudenkauf, Benjamin Miner, Alisa L. Newton, Joseph K. Gaydos, Janna Wynne, Cathy L. Groves, Gordon Hendler, Michael Murray, Steven Fradkin, Mya Breitbart, Elizabeth Fahsbender, Kevin D. Lafferty, A. Marm Kilpatrick, C. Melissa Miner, Peter Raimondi, Lesanna Lahner, Carolyn S. Friedman, Stephen Daniels, Martin Haulena, Jeffrey Marliave, Colleen A. Burge, Morgan E. Eisenlord, and C. Drew Harvell. "Densovirus associated with sea-star wasting disease and mass mortality." Proceedings of the National Academy of Sciences 111, no. 48 (2014): 17278-7283. doi:10.1073/pnas.1416625111.
(3) "Pacific Rocky Intertidal Monitoring: Trends and Synthesis." Gordon Science Oregon State. http://gordon.science.oregonstate.edu/marine1/observations.html?site=Coal Oil Point ST.
(4) "Pisaster giganteus - Giant Spined Star." SIMoN. http://sanctuarymonitoring.org/species/pisaster/giganteus/giant-spined-star.
(Photograph) Lovell and Libby Langstroth © California Academy of Sciences
- rocky intertidal