If you’ve ever explored the shores or tidal pools of our ocean, chances are you’ve spotted some small, cone-shaped shells clinging to rocks. These are sea snails called limpets, and they are far more resilient and important than they may appear.
To feed, limpets use a tongue-like organ called a radula. The radula is covered in rows of tiny teeth, each measuring less than a millimeter in length. The remarkable strength of limpet teeth stems from their structure, which is made of chitin—a primary material in the exoskeletons of insects and crustaceans—and reinforced by the mineral goethite. Researchers in the U.K. have found that goethite is the strongest known biological material on Earth and is even stronger than Kevlar. Limpets use their incredibly sturdy teeth and radula to scrape algae off rocks with ease, earning them the nickname the “bulldozers of the seashore.”
To move across rock formations, limpets utilize tidal movements and their strong muscular “foot.” This foot is different than a human foot in that it acts as a suction cup to firmly attach the limpet to rocks and withstand the force of waves. The foot also produces mucus, which helps with adhesion and eases movement by allowing the limpet to glide across rock formations. As limpets travel, they also leave behind a trail of this mucus, which helps guide them back to a preferred resting spot during low tide.
Over time, a limpet creates a “home scar,” a small indentation in the rock formed by repeatedly scraping and returning to the same location. During low tide, the limpet uses its foot to seal itself tightly to this home scar and prevent it from drying out. Limpets can live for more than 20 years, often remaining on the same rock their entire lives.
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Why are Limpets Important for Our Ocean?
Limpets play an essential role in controlling algae growth on the rocky surfaces of our ocean. By clearing algae, limpets create space for other species, like barnacles and mussels, to settle and thrive. Those species, in turn, provide habitat for countless microorganisms and other marine life.
Limpets also provide a significant food source for fish, birds and even humans. In fact, the earliest known evidence of humans eating limpets dates back 164,000 years to a cave in South Africa. Today, limpets are considered a delicacy in many coastal cultures worldwide.
Unfortunately, limpets face the same threats that affect all ocean species. Dirty fossil fuel production, oil spills and other human stressors are causing our ocean to absorb more carbon and making seawater more acidic. Limpets are particularly impacted by ocean acidification caused by a changing climate. Ocean acidification causes the calcium carbonate in the limpet shells to dissolve, making it difficult to maintain normal function, growth and reproduction.
At Ocean Conservancy, we know that a responsible and rapid transition away from oil and gas toward 100%-clean ocean energy by 2050 is both possible and essential to protect our ocean from the climate crisis. But we cannot do this work alone. Take action and demand bold ocean-climate solutions that protect limpets and all marine species.
