The humble limpet is a resilient marine mollusc that has cleverly adapted to life in one of the sea's harshest environments. You've likely seen them decorating the outer edges of rockpools and clinging tightly to the jagged rocks of an intertidal zone, but did you know that these commonplace creatures are much more extraordinary than meets the eye?
Unassuming at first glance, limpets must be able to survive harsh coastal conditions caused by crashing waves, drying winds, and constant exposure. How have they adapted to be so resilient? Limpets must anchor themselves with remarkable strength to the shore and seek sustenance by feeding on microscopic algae, both of which feats are achieved thanks to insanely strong teeth.
The evolutionary success of the humble limpet lies in its extraordinary feeding adaptation. Underneath that familiar, tough shell, you'll find thousands of rows of microscopic teeth, made from one of the toughest natural materials in existence. It's for this reason that limpet teeth are said to be the strongest biological material ever tested and five times stronger than spider silk.
How many species of limpet are there in the UK?
Around 15 species of true and false limpets are recorded in UK waters, though the common limpet is the most widespread.
What are true and false limpets?
True limpets belong to the group Patellogastropoda. They’re the classic cone-shaped limpets commonly found on rocky UK shores. Meanwhile, false limpets are species from other snail groups that have independently evolved a similar flattened, conical shell. These include keyhole limpets and slipper limpets.
How many teeth do limpets have?
They possess thousands of microscopic teeth arranged in rows on a ribbon-like tongue called a radula, which is often cited as one of the strongest natural materials.
What are limpet teeth made from?
Limpet teeth are formed from a protein scaffold reinforced with iron-based minerals, giving them exceptional strength. The main mineral in action here is goethite, which is an iron ore commonly found in soil and sediment. Goethite was historically used as a brown ochre pigment.
How are limpet teeth so sharp?
They stay sharp because new teeth continuously grow at the back of the radula and move forward, while older teeth wear down. Effectively, the teeth are self-sharpening through constant replacement and don't degrade with age like we see in other animals.
What are limpet teeth made for?
They are used to scrape algae and biofilm off hard rocks, allowing them to feed effectively in the typically harsh intertidal zone.
What do limpets eat?
Limpets mainly graze on algae and biofilm, scraping them off rocks with their radula. Biofilm is a thin, sticky layer of microorganisms (mainly bacteria and algae) that grows on surfaces and is held together by a self-made protective slime.
Can limpets live outside of their shells?
No – removing a limpet from its shell is fatal, as the shell is essential for protection and preventing dehydration.
How long do limpets live?
Most limpets live around 5 to 10 years, though in good conditions some can reach 15 to 20 years.
Can you eat limpets?
Technically, humans can eat limpets and in some coastal regions of the UK, they have traditionally been collected as food. However, limpets are typically tough and rubbery. They require thorough cooking to be palatable and are not considered particularly tasty. They can also be difficult to harvest sustainably.
Guide to limpet species found in the UK
Common limpet, Patella vulgata
The most widespread limpet in the UK, the common limpet, lives on rocky shores around Britain and Ireland. It grazes on algae and always returns to the same spot on the rock after feeding.
Black-Footed Limpet, Patella depressa
Found mainly along the warmer coasts of southwest England and Wales, this species has a flatter shell than the common limpet. It prefers lower shore habitats exposed to strong wave action.
China Limpet, Patella ulyssiponensis
Called the China limpet because of its delicate shell shape, this species inhabits sheltered rocky shores in southern and western Britain. It is less common than the common limpet and tends to live lower on the shore.
