Excellent photos. Thank you!
One of the species is amphiatlantic (Littorina obtusata) and personally
I know that species from mary places on the European Atlantic and North
Sea coasts, and the shell morphology of the American specimens really
looks different to me compared to the European ones (American specimens
are much less flat than over here). Also: on the European side of the
Atlantic L.obtusata forms a species complex with L.fabalis. Thus I'm
wondering if the American L.obtusata are really that species or a
distinct, but different, member of the species complex.
See also e.g.:
https://bmcecolevol.biomedcentral.com/articles/10.1186/s12862-019-1561-6
Sincerely, Erick
----------------------------------------------------------------------
[log in to unmask] - a forum for informal discussions on molluscs
To leave this list, click on the following web link:
http://listserv.uga.edu/scripts/wa-UGA.exe?SUBED1=conch-l-L&A=1
Type your email address and name in the appropriate box and
click leave the list.
----------------------------------------------------------------------