We have a wildlife-friendly garden, and part of that is a pesticide-free compost heap. When it needs to be turned over, the usual creatures are plentiful - earthworms, slugs, woodlice and so on - but sometimes something less familiar appears, brought to me by my loving wife...
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| A mass of about 20 worm-like creatures attached to a decaying slug. |
I usually deal with invertebrates with legs, but I like a challenge so, holding my nose (the slug-remains were highly fragrant!) looked more closely.
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| One of the 'worms' off exploring. |
It was clear very quickly that these weren't leeches. Although they moved like them, they didn't have the segmentation or mouthparts - instead they were a type of flatworm. A quick look at
Jones (2005) told me they were
Kontikia ventrolineata, an Australian species introduced through the ornamental plant trade.
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| Kontikia ventrolineata - the pair of grey lines on the dorsal surface is a key identification feature. |
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| Kontikia ventrolineata - the series of light and dark bands on the ventral surface is another key identification feature, and give it its specific name. |
The garden plant trade has introduced several Australasian flatworms to Britain,and some such as the Australian flatworm
Australoplana sanguinea and the New Zealand flatworm Arthurdendyus triangulatus can be problematic as they are predatory and hunt earthworms, and may impact on populations of our native species which are so important for soil quality. Fortunately K. ventrolineata is probably less troublesome as it feeds on small snails and possibly slugs, as well as (in this case) scavenging. As yet, I am unaware if it has an impact on our native molluscs, though it is widespread in southern and southwestern England (and as I understand it has been found as far north as Scotland, although the NBN currently holds no records). So, observations and data are always welcome, and if you see this species in England or Wales, let Hugh Jones know via the Natural History Museum in London (scroll down, he's a Scientific Associate), or in Scotland, you'll want Brian Boag who works on introduced and invasive species.
Reference
Jones, H.D. (2005). Identification: British land flatworms.
British Wildlife 16(3): 189-194.
