What is a Nudibranch?

Nudibranch

Nudibranch (Facelina auriculata) ©Alex Mustard/2020VISION

What is a Nudibranch?

Scientific name: Over 100 different species in the UK’
Nudibranchs, also known as sea slugs, are much like their land-based relatives that you may spot in your garden. But, unlike your regular garden slug, the nudibranch can incorporate the stinging cells from their prey into their own bodies – giving them a defence against predators!

Species information

Statistics

Length: Species vary in size from a few millimetres to several centimetres in length. The largest British species has been recorded at 20cm.

Conservation status

Common

When to see

January to December

About

Nudibranchs, also known as sea slugs, are soft-bodied marine molluscs that lack external shells. There are more than 100 species in UK seas, where they feed on seaweeds, sea mats, sponges, anemones and other nudibranchs. Unlike your regular garden slug, the nudibranch can incorporate the stinging cells from their prey into their own bodies – giving them a defence against predators. They are often brightly coloured – with some resembling a fireworks display!

How to identify

Nudibranchs come in many colours and forms, often with two horn-like tentacles or feathery gills.

Distribution

Widespread around the UK.

Did you know?

Nudibranchs are hermaphrodites, which means they have both male and female reproductive organs.

How people can help

When rockpooling, be careful to leave everything as you found it - replace any rocks you turn over, put back any crabs or fish and ensure not to scrape anything off its rocky home. If you want to learn more about our rockpool life, Wildlife Trusts around the UK run rockpool safaris and offer Shoresearch training - teaching you to survey your local rocky shore. The data collected is then used to protect our coasts and seas through better management or through the designation of Marine Protected Areas. The Wildlife Trusts are working with sea users, scientists, 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 checking out our Action Pages.

Check out some of our cool nudibranchs!

A coastal landscape, with the sea gently lapping at smooth rocks as the sun sets behind scattered clouds

Mark Hamblin/2020VISION

As a charity we rely on memberships

Memberships help us campaign for better protection and management of our seas.

Join today

Get marine updates straight to your inbox

Receive our monthly newsletter packed with marine conservation news from around the world!

Sign up
Sea

Mark Hamblin/2020VISION

Seas in crisis

Plastic-strewn beaches, fisheries on the verge of collapse and the ever growing effects of global climate change.

What The Wildlife Trusts are doing