Hornwrack

Flustra foliacea

  • Where it lives:

  • Non native species

About

Hornwrack is a bryozoan - a colony of individual animals known as zooids. If you look closely at the hornwrack, you will see it is a mesh of little boxes; each of which is home to an individual zooid. The zooids filter feed on phytoplankton using special feeding tentacles called a lophophore. Hornwrack grows in bushy clumps attached to shells, stones, cobbles or rocky seabeds and is a pale beige colour. They only grow during spring and summer, resulting in distinct growth lines. Hornwrack might not look that tasty to you, but it is a favourite food of sea urchins, sea slugs and even sea spiders!

How to identify

A papery beige lobed frond, often mistaken for seaweed. Individual zooids are tongue shaped. The frond is 2 zooids thick - known as bilaminar.

Did you know?

Hornwrack smells like lemons when freshly collected! Though this citrusy scent is lost in the dried pieces found on beaches.

How people can help

The Wildlife Trusts are working with fishermen, researchers, politicians and local people towards a vision of 'Living Seas', where marine wildlife thrives. Do your bit for our Living Seas by supporting your local Wildlife Trust or take a look at our Action pages.