Native
Stenosoma are elongated Idoteids with no distinct pleon somites, so that the pleon and the telson are completely fused.
The triangular coxal plates give S. lancifer a serrated shape. The pleotelson expands before narrowing sharply to an elongated point so that it is shaped like the nib of a fountain pen. Males grow to 22.4 mm, with females being smaller. The species is a reddish colour, sometimes with pale medial dots or stripe.
This species is found amongst red algae at and beyond the low spring tide limit. Washing handfuls of red seaweed can be a productive technique if the conditions are right. It has been recorded in the Channel Islands and along the south coast of England, from Kent to Scilly, as well as on the north Cornwall and Devon coasts.
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.
World Register of Marine Species (WoRMS): https://www.marinespecies.org/aphia.php?p=taxdetails&id=295701
Aphotomarine: https://www.aphotomarine.com/isopoda_stenosoma_lancifer.html
Ocean Biodiversity Information System (OBIS) distribution map: https://mapper.obis.org/?taxonid=295701
