The mysterious alien "Ghost Slug"

Sketch of an extended Ghost slug, with notable features
Sketch of an extended Ghost slug, with notable features. Average length of adult slug = 6/7cms when extended.
An adult Ghost Slug, about 7cms long.
An adult Ghost Slug, about 7cms long.
The Ghost Slug's blade-like teeth
The Ghost Slug's blade-like teeth, each about half a millimetre long. These are much longer and sharper than those of herbivorous species.
Close-up of the Ghost Slug's head.
Close-up of the Ghost Slug's head. The eyes, if present, would normally be at the tips of the two upper (longer) tentacles.
A baby Ghost Slug
A baby Ghost Slug

British gardeners may soon encounter an unexpected arrival — the bizarre Ghost Slug. First discovered in a Cardiff garden in 2007, the animal has been described as a species new to science by biologists at Amgueddfa Cymru and Cardiff University.

Scientists are researching this creature — and we need your help to find out just how common the Ghost Slug is.

Update, May 2009: Ghost Slug Update - Spring 2010


The Ghost Slug is an alien species, introduced to Britain around the roots of garden plants. Its nearest relatives live in the mountains of eastern Europe, Georgia and eastern Turkey.

What is the Ghost Slug?

Unlike most slugs, the Ghost Slug is carnivorous, killing earthworms at night with powerful, blade-like teeth, sucking them in like spaghetti. It is also unusual in having no eyes (it is probably blind) and is almost completely white.

It spends most of its time underground, squeezing its flexible body into cracks or tunnels to get at earthworms, which it detects by smell or taste.

Why do we want to hear from people who find it?

Very little is known about this species, but we know that it eats earthworms and can survive and breed in British gardens.

Earthworms in general are beneficial to gardeners and agriculture, and provide food for much of our wildlife, so there is a possibility that Ghost Slugs could become a pest.

To help us find out how widespread the Ghost Slug is, we are very keen to hear from anyone who finds it. To help people recognise it we have produced a free colour identification guide — you can download this guide below.

Where to find the Ghost Slug

The best way to search for Ghost Slugs is to look under plant pots, paving slabs or stones on soil, or while digging in gardens, allotments or compost heaps. They may prefer loose, rich soils with plenty of earthworms and are probably able to dig quite deep.

The babies, only a few millimetres long when they hatch and rather skinny, are quite conspicuous against dark backgrounds.

The guide also includes the Shelled Slug (Testacella sp.), which, like the Ghost Slug, is also quite mysterious. Information on sightings would also help us understand more about this slug.

If you see either Ghost Slugs or Shelled Slugs, we would love to hear from you. Please contact us using the details on the guide.

Your free identification guide

Click the image to download the identification guide.

Download the Ghost Slug identification guide [PDF - 485 KB]
Download the Ghost Slug identification guide [PDF - 485 KB]

Ghost Slug Guidelines

We have had dozens of responses from all over Britain and Ireland so far. The number of confirmed Ghost Slug records is quite small, however, and we are still keen to hear of any sightings. If you think you have seen the Ghost Slug, please note the following points:

  • tell us which species you saw (Ghost Slug, Shelled Slug, etc.)
  • tell us where and when you saw it (please include postcode for mapping purposes)
  • include digital photos if you have any. Photos or specimens are currently required to verify all Ghost Slug records.

Contact details:

We will respond to all email or 'phone enquiries. 

Phone: (029) 20573110

Article Date: 9 July 2008

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