stevegregory's picture

Woodlouse under plank

Observed: 27th April 2013 By: stevegregory
British Myriapod and Isopod Group
Invertebrates expert
P-dilatatus-plank
P-dilatatus-head
P-dilatatus-telson
Description:

Solitary woodlouse found under plank beside large, well rotted , compost heap in garden. Large, c. 15mm in length.

Identifications
Species interactions

No interactions present.

Comments

dejayM's picture

Marine!

How interesting Steve. I wandered the Web Cellar awhile and found this as a Marine Species here (in Oxford!)
http://www.marinespecies.org/aphia.php?p=taxdetails&id=262272
Comment?
I also see it's a Giant Isopod at only 15mm.
Explain!
Distinctive anyway, so yet another agreement.

stevegregory's picture

WoRMS indeed......

Hi Derek. P. dilatatus is fairly common in stable yards and dairy farms, but easily 'lost' among the ubiquitousness of Onsicus/Porcellio scaber). It does occur on soft coastal cliffs, but never lower down than the splash zone. I had a look at the WoRMS site. It seems all Isopod species (including terrestrial Oniscidea and freshwater Asellota) have been taken directly from the World Database (held at Smithsonian). Most of the rest are marine as you will know. As to size, most GB woodlice are between 2mm and 5mm in size. A full grown P.dilatatus is a relative monster, but hardy on a par with the real Arctic 'Giant Isopod'.

Steve