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Keyhole limpet

Keyhole limpet ©Nigel Phillips

Keyhole limpet

Found on rocky shores and seabeds, the Keyhole limpet gets its name from the little hole at the tip of its shell.

Scientific name

Diodora graeca

When to see

January to December

Species information

Statistics

Length: 4cm
Common

About

The keyhole limpet lives on rocks and under stones on rocky shores and the seabed down to 250m deep. It feeds on sponges, including the Breadcrumb Sponge, using its rasping tongue. Called a radula, this rasping tongue is the world's strongest biological structure - it has to be to constantly scrape sponges off tough rocks without wearing away. Their shell is oval and conical, with a distinctive hole at the tip that gives them their name.

How to identify

Similar to the common limpet, but more oval in shape and with a characteristic 'keyhole' shaped opening in the top of the greyish shell, through which it breathes when underwater. The shell is around 4cm length and features characteristic bands of green or brown.

Distribution

Found on rocky shores around the south and west of the UK. Also found in the Orkney Islands off Northern Scotland.

Did you know?

The hole at the tip of their shell is used for respiration.