Taxonomy Search:

Pseudosphaeroma sp. A
Image courtesy of Plantweb (, please note that this image is of P. barnardi, not the unidentified Pseudosphaeroma sp. A.
Pseudosphaeroma sp. A
Taxonomic Group: Crustaceans-Isopods


Pseudosphaeroma sp. A is a marine and brackish water isopod. Its taxonomic and biogeographic history are complicated and not fully understood; however it has been introduced (based on recent occurrence records) into California and Oregon. North American specimens are similar to a ‘smooth’ and ‘nodular’ form of Pseudosphaeroma from New Zealand. Little is known about the life history or ecology of this unidentified species, but in Oregon it was found in marsh banks, woody debris and sandstone terraces, often associated with another introduced isopod, Sphaeroma quoianum.

* Content for this species is based on the literature and peer review is pending - if you have comments or feedback please contact Paul Fofonoff at

This is some default tab content, embedded directly inside this space and not via Ajax. It can be shown when no tabs are automatically selected, or associated with a certain tab, in this case, the first tab.


Fofonoff PW, Ruiz GM, Steves B, Simkanin C, & Carlton JT (2018)
National Exotic Marine and Estuarine Species Information System.
Access Date:

Marine Invasions Lab
Smithsonian Environmental Research Center

P.O. Box 28
647 Contees Wharf Road
Edgewater, MD 21037-0028 Tel: 443 482 2200
Fax: 443 482 2380

Databases Overview| Chesapeake Bay | National Database |