D Cole's picture

Unusual worm

Observed: 22nd July 2012 By: D Cole

We have been finding these worms in our garden for a few months & have been unable to identify them. They are found in damp grassy areas. The colour is blackish-brown with a prominent green-yellow stripe running along the back. Approx 2 ins long. Children thought could be a slow worm but on close observation has worm-like body and ends.

Species interactions

No interactions present.


GrizzledBadger's picture

There are some leeches that

There are some leeches that will move over wet grass. There is also a worm that came in from N.Zealand, in the pots of such as Tree Ferns.


Matt Smith's picture


Not a leech, possibly a New Zealand Flatworm?

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Thistle's picture


Can you tell us what colour the underside of the worm is?

Christian Owen's picture


Not something that i can point to. It would be good if you could contact Hugh Jones who is an expert on Terrestrial Flatworms...see what he has to say.

Contact: flat worm @ btopenworld . com

Do let us know how you get on...

D Cole's picture

unusual worm

Thanks very much for your comments, I agree it seems to be some kind of flatworm and I will follow up your advice and report back. Unfortunately we're not sure of the underneath colour as we didn't look at the time and couldn't find them today in the cool weather! Will keep looking.

D Cole's picture

unusual worm


D Cole's picture

unusual worm

Hugh Jones has provided much helpful information, identifying the species as almost certainly Caenoplana bicolor (originally Geoplana bicolor) originating from Queensland, Australia. He comments that C. bicolour has a pale blue underside with a pale median line. Another another similar species, C. variegata has a pale ventral surface. It's not known whether they are predatory or scavengers at present.

 I will try to locate more specimens and check the underside, also take more photos, a video and send one for a proper id.

The species seems to have only been found in 2 places in the UK, being Kew Gardens and The Living Rainforest in Newbury, both indoors.

We are on the edge of the New Forest in a semi rural area with plenty of wildlife, and mild winters usually so they may be able to survive.

I will report back if I find out anything further.

Thanks again to all.

Christian Owen's picture


Thanks for updating us on this. And well done on an interesting find.

Thistle's picture

C bicolor? C coerulea?

Information on C bicolor is a little hard to come by but sources seem to suggest that it is a marine species. My question about the colour of the underside was leading towards the possibility of C coerulea. Comments?

gramandy's picture


agree with Hugh after seeing images. Amazing they have found their way into your garden. Interesting find and unusual as they are not commonly around.

D Cole's picture

unusual worm

Thank you for your comments. I have no idea how they have arrived in our garden either! I do wonder if they found their way out of a pot plant or an introduced plant at some point as I can't think how else they could arrive. The other examples found in the UK were indoors apparently. I have young daughters who are avid 'bug hunters' and it is to their credit they kept bringing me these 'unusual worms' they had found!