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Australian Flatworm
Australoplana sanguinea

Last edited: September 23rd 2016

Australian Flatworm

Australian Flatworm - Australoplana sanguinea

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Short description of Australoplana sanguinea, Australian Flatworm

2-8 cm long, 2-5 mm wide, flattened. Orange with peach-coloured front end or pinkish-orange after feeding. Many minute eyes (black dots) round the anterior and lateral margins.

Impact summary: Australoplana sanguinea, Australian Flatworm

It eats only earthworms and may affect earthworm population structure.

Habitat summary: Australoplana sanguinea, Australian Flatworm

In gardens, garden centres, woodland and other damp sites. Usually found under stones, planks, plastic sacks and other refuges on the soil surface.

Overview table

Environment Terrestrial
Species status Non-Native
Native range Australia
Functional type Predator
Status in England Non-Native
Status in Scotland
Status in Wales Non-Native
Location of first record Scilly (1) & Dorset (9)
Date of first record 1980


Native to eastern Australia.

First Record

The first GB specimens were found on Tresco, Isles of Scilly in 1980.

Pathway and Method

Probably introduced with imported plants.

Species Status

Since the initial identification in 1981, it has been found throughout SW England and sporadically further north.

Dispersal Mechanisms

Presumably by human transport of contaminated plants or plant containers.


Apparently reproduces mainly by fission, worms splitting in two, each half regenerating into a complete worm. Sexual reproduction may occasionally occur, over a 10-year study in one infested garden only 3 egg cocoons were seen.

Known Predators/Herbivores

None known for certain, but ground-feeding birds may take them if the flatworms are not under a suitable refuge.

Resistant Stages

None known.

Habitat Occupied in GB

Gardens, garden centres, adjacent land.

Mainly SW England but also sporadically in NW England, Wales. One record in Scotland.

Environmental Impact

Eats only earthworms and can affect the population structure, some earthworm species being more affected than others. Consequent changes to soil structure and fertility have been suggested but there has been no systematic studies of this.

Health and Social Impact

None known.

Economic Impact

None known.


Ball I.R. & Reynoldson T.B. (1981) British Planarians. Synopses of the British fauna (New Series), No 19. Eds D.M.Kermack & R.S.K.Barnes. Linnean Society of London and The Estuarine and Brackish-Water Sciences Association. Cambridge University Press.

Jones, H.D. (2005) British land flatworms. British Wildlife, 16, 189-194.

Biology, ecology, spread, vectors

Santoro, G. & Jones, H.D. (2001) Comparison of the earthworm population of a garden infested with the Australian land flatworm (Australoplana sanguinea alba) with that of a non-infested garden. Pedobiologia, 45, 313-328.

Jones, H.D., Green, J, Harrison, K & Palin, D.W. (2001) Further monthly records (1994 to 2000) of size and abundance in a population of the "Australian" flatworm, Australoplana sanguinea alba in the U.K. Belgian Journal of Zoology, 131 (Supplement 1), 217-220.

Management and impact