King Tides arrived this weekend in Southern California, and with them, a rare opportunity to see marine life that’s typically underwater.
On Broad Beach, in western LA County, this constellation of five sea stars was spotted at low tide on a large boulder. Considered a keystone species in intertidal zones, sea stars keep mussels in check, which in turn helps keep the kelp beds healthy.
Curious about the different colors, I learned that diet plays a role in the pigment of the creatures. “These voracious predators feed on mollusks and crustaceans in intertidal areas. Those that have access to mussels (Mylitus spp.) absorb red and orange pigments known as carotenoids from the flesh of these bivalves, the researchers argued. Ochre stars in isolated inlets didn’t have abundant populations of mussels to prey on, and fed more frequently on barnacles. Barnacles lack carotenoids in their flesh, so stars that feed on them don’t accumulate the pigments and are predominately purple.” (Source: https://aquarium.org/ochre-sea-stars-come-different-colors/ )
On the other side of the rock, I found these two riding out the low-tide event. All the small nearby mussel shells are halved, perhaps having been a tasty snack for the hungry sea stars.
“They digest prey outside of their bodies by extruding their stomach out through their mouth and enveloping their meal. Once the food is digested, their stomach is drawn back into their body.” (Source)