Dynamene bidentata (Adams, 1800)


Both males and females of this species have a single medial indent in the posterior border of the pleotelson. Males are also characterised by two backwards projections from pereonite 6. Unlike Dynamene magnitorata, these taper to a point. Males are up to 7.0mm, females up to 6.0mm.

Distribution and Habitat

This species occurs on southern and western British as well as Irish shores. It appears to be absent from eastern Britain, the single record in south-east Scotland probably representing a stranding rather than a resident population (Vieira et al. 2016, who wrongly assign this record to north-east England). It is found in rock crevices, empty barnacles and amongst seaweed, mostly below MTL.



Naylor, E. & A. Brandt. 2015. Intertidal Marine Isopods. Synopses of the British Fauna (New Series), No. 3. Field Studies Council, for The Linnean Society of London.

Vieira, Pedro E., Henrique Queiroga, Filipe O. Costa, David M. Holdich. 2016. Distribution and species identification in the crustacean isopod genus Dynamene Leach, 1814 along the North East Atlantic-Black Sea axis. ZooKeys 635, 1–29.