Ochre Sea Star

Fascinating facts about the Ochre Sea Star

• The ochre sea star acts as a keystone predator, keeping mussel populations in check and allowing many other intertidal species to thrive. When a few individuals are removed, mussels such as Mytilus californianus quickly dominate the space, turning a diverse community into a near-monoculture.
• The ochre sea star is remarkably resilient, able to survive the loss of a substantial portion of its internal fluids without fatal consequences. Laboratory observations note that it can tolerate a loss of thirty percent of its body weight in body fluids, a level that would cripple most marine invertebrates. This durability helps it persist in the harsh, wave-swept intertidal zones where sudden stressors are common.
• Each tube foot of the ochre sea star ends in a tiny suction cup, giving the animal a firm grip on the rocky substrate even when waves crash over the shore. These suckers enable it to remain anchored in heavily wave-swept areas where many other organisms would be dislodged. By clinging securely, the sea star can hunt for prey and move across the intertidal zone despite the relentless surf.
• An adult ochre sea star can eat a large number of mussels each year, using its tube feet to pry the shells apart and then everting its stomach to digest the flesh. It can pull open the tightly sealed valves of Mytilus californianus and Mytilus trossulus, inserting its stomach through the narrow gap where the byssal threads emerge.
• The ochre sea star can endure ocean-acidification conditions that exceed future projections, surviving in water warmed to 21 °C with carbon dioxide levels of 770 ppm. Experiments showed the animals lived through these stressors, indicating a remarkable tolerance. Scientists attribute this resilience to the star's nodular calcium structure, which lets it offset carbonate loss by growing additional fleshy tissue.

Sources

Every fact above was checked against these pages, and kept only where one of them states it.

• Wikipedia

At a glance

About the Ochre Sea Star

In the vibrant tapestry of the intertidal zone, the ochre sea star emerges as a masterful forager, its flexible, sun-kissed arms rippling like a slow-motion dance as it navigates the rocky shores in search of its prized prey, the mussel. With calculated precision, it prises open the tightly sealed shells, a testament to its remarkable adaptability and tenacity in this unforgiving, wave-battered world. As it moves, its very presence orchestrates the delicate balance of the ecosystem, a reminder of the intricate, interconnected beauty that thrives in these coastal realms.

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