Learning About Limpets

What tide pool animal sleeps in a rock bed and helps to cure cancer? The answer is the limpets. Though limpets look like just lifeless shells, as with all mollusks, a fascinating animal lives inside.

Strange Facts About Limpets

Limpets scrape algae, small green plants, off of rocks with their rough tongues. They slide around at night when they can be safe from predators. Each limpet also scrapes a limpet-sized pit or groove in the rock to make a bed. After grazing, the limpet goes back to its bed by following the trails it made by scraping the algae-- just like a lawn mower cuts a path through grass.

A type of limpet called the Keyhole Limpet invites a worm to live under its shell. When a starfish comes to attack, the worm zaps out and bites the starfish to make it retreat.

Limpets can also "run away" from attacking starfish who invade their home rocks. In the world of limpets, running means moving only a few inches an hour.

Limpets Face Strong Waves

Limpets get hit with more than 8000 wave crashes a day. To avoid tumbling off their rocks, limpets are shaped like domes to protect themselves against the waves. In contrast, mollusks that have spiraled shells, such as periwinkles, are easily rolled around by the waves.

Low Tide Alert!

At low tide, to avoid drying out, limpets trap some water inside their shells. They create their own tide pools right inside their shells.

Limpets to the Rescue

Chemicals from the Keyhole Limpet are being tested in the treatment of cancer. This discovery is just one reason why tide pool animals are important and should be protected.

Limpets help other animals to live in tide pools. Limpets eat so many plants that they make bare spots on the rocks where other tide pool animals like barnacles can come and live. When oil is accidentally spilled along the shore, limpets die. They arenít able to clear the plants, and other tide pool animals canít find homes to live.

Finding Limpets

Look closely on the sides of rocks to find limpets clinging on to avoid being swept away by waves. Limpets may be tan, greenish brown or gray. Do not pull a limpet off its rock; pulling limpets can hurt them.

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Designed and written by Sherry Weaver Smith, last modified 3/2002.