Porcellio scaber
System : Terrestrial
Kingdom
Phylum
Class
Order
Family
Animalia
Arthropoda
Malacostraca
Isopoda
Porcellionidae
- General
- Distribution
- Impact
- Management
- Bibliography
- Contact
Common name
woodlouse (English)
Synonym
Oniscus granulatus , Lamark 1818
Porcellio nigra , Say 1818
Porcellio brandlii , Milne-Edwardes 1840
Porcellio dubius , Koch 1840
Porcellio asper , Koch 1847
Porcellio montezumaex , Saussure 1857
Porcellio paulensis , Heller 1865
Porcellio seaber , Bate and Westwood 1868
Porcellio graniger , Miers 1876
Porcellio graniger , Biidde-Lund 1885
Porcellio nigra , Say 1818
Porcellio brandlii , Milne-Edwardes 1840
Porcellio dubius , Koch 1840
Porcellio asper , Koch 1847
Porcellio montezumaex , Saussure 1857
Porcellio paulensis , Heller 1865
Porcellio seaber , Bate and Westwood 1868
Porcellio graniger , Miers 1876
Porcellio graniger , Biidde-Lund 1885
Similar species
Summary
The terrestrial crustacean Porcellio scaber was first recorded on the sub-Antarctic Marion Island during a survey in April 2001. Searches conducted between September 2001 and April 2002 yielded as many as 391 specimens including gravid females. There are concerns that P. scaber may have an impact on native invertebrates in its introduced range. For example, Gough Island's only indigenous terrestrial isopod Styloniscus australis is rare in lowland habitats where the introduced terrestrial isopod P. scaber is abundant; however it is abundant on upland sites where P. scaber is rare. P. scaber may also compete with primary native detritivores on Marion Island such as Pringleophaga marioni and earthworms.
Species Description
The body of Porcellio scaber is densely covered with tubercles. Its colour is usually a very dark grey, but can also be quite red or variegated with yellow. Albino specimens have been recorded. The two joints of the flagellum are of the same length and together equal that of the last joint of the peduncle. Air-tubes are present on the outer plates of the first two abdominal appendages (Webb & Sillem 1906).
Lifecycle Stages
Juveniles are carried ventrally by the females characteristic of this species (Carefoot 1993, in Slabber & Chown 2002).
Habitat Description
Porcellio scaber not only inhabits litter stratum in forests, but also inhabits middens, gardens, and cellars in human habitations, preferring moist microclimates (Wang & Schreiber 1999). \r\n
Several studies have investigated the low-temperature tolerance of P. scaber. In the Palearctic, this species has a lower lethal temperature of approximately minus 4.6 degC (Tanaka and Udagawa 1993, in Slabber & Chown 2002) and can survive for at least 1 week at minus 2 degC, so long as individuals have access to food and have been previously exposed to relatively low, but not subzero, temperatures (Lavy et al. 1997, in Slabber & Chown 2002).
Reproduction
On Marion Island Porcellio scaber appears to be reproductively most active over the summer months from October until March (Slabber & Chown 2002). Day-length variation and low temperatures might be responsible for inducing seasonal reproduction (Slabber & Chown 2002).
Nutrition
Porcellio scaber feeds on detritus (Slabber & Chown 2002). On Marion Island P. scaber feeds on detritus including plant and animal remains, soil algae and fungi, as is the case with most isopods (Barnes 1980, Warburg 1993, Lavy et al. 2001, in Slabber & Chown 2002).
Pathway
Porcellio scaber may be moved to new locations through human-aided dispersal, for example, through the movement of ballast, rubble, agricultural products, compost and plants (Wang & Schreiber 1999, in Slabber & Chown 2002).
Principal source: Slabber, S. & S. L. Chown, 2002. The first record of a terrestrial crustacean, Porcellio scaber (Isopoda, Porcellionidae), from sub-Antarctic Marion Island. Polar Biol (2002) 25: 855–858
Compiler: IUCN SSC Invasive Species Specialist Group (ISSG) with support from the EU-funded South Atlantic Invasive Species project, coordinated by the Royal Society for the Protection of Birds (RSPB)
Review:
Publication date: 2009-04-28
Recommended citation: Global Invasive Species Database (2024) Species profile: Porcellio scaber. Downloaded from http://iucngisd.org/gisd/species.php?sc=1460 on 25-11-2024.
General Impacts
Porcellio scaber has an island wide range on Gough Island and introduced invertebrates form a large proportion of the invertebrate community. Introduced detritivores on Gough like P. scaber, lumbricid worms, and the millipede Cylindroiulus latestriatus can have long term effects on nutrient cycles of its peaty soils, that lack such species and have formed in the absence of rapid organic breakdown. Long term effects can include changes in flora and faunal communities (Jones et al. 2003).
There are concerns that P. scaber may have an impact on native invertebrates. For example, Gough Island's only indigenous terrestrial isopod Styloniscus australis is rare in lowland habitats where the introduced terrestrial isopod P. scaber is abundant; however it is abundant on upland sites where P. scaber is rare. P. scaber may also compete with primary native detritivores on Marion Island such as Pringleophaga marioni and earthworms (Jones et al. 2003).
Management Info
On Marion Island the most appropriate conservation strategy would be complete eradication of Porcellio scaber. This recommendation has been made to the Prince Edward Islands Management Committee, which oversees conservation at the islands (Marion and Prince Edward islands). Eradication attempts are now underway (Slabber & Chown 2002).
