First, Splendid site
(http://modena.intergate.ca/personal/seashell/bcframe.html) - great
Photos, especially of live animals!!  Bravo.  The species you are
calling Lottia alveus (Conrad), seems to be an elongated form of pelta
Rathke, or perhaps strigatella - it is lighter, more transluscent, but
if you take a look at the specimens you find in the vicinity, NOT on
Zostera, i think you will find they are the same species.  A similar
thing occurs in Nova Scotia at a few localities where eel-grass
communities are well established - Lottia testudinalis (Muller) has (in
the absence of alveus, which formerly occupied that habitat) expanded
its normal niche to take advantage of the juicy algae on the grass
blades.  It is unknown whether those engaging in this specialization
comprise a genetically distinct sub-population, or whether they just
grow ligher and more elongate on the eelgrass, as a response to
different living conditions (would make a great honors thesis!!).  There
are no references, since i seem to be the only one around here that has
taken serious notice of the phenomenon.  To find ths occuring on the
other coast, is interesting, to say the least.

From the rather dry (but still great!!) North,
Ross.

Peter Egerton Wrote:

Hi all,

In adding species to my Web site I've come across something a little
puzzling. I Boundary Bay, just south of Vancouver BC, I collected a
number of limpets that I've labeled Lottia alveus. This limpet was very
abundant living on eelgrass stems.

What puzzles me is that a number of Web sites call it an extinct
species. One is http://ucmp1.berkeley.edu/davidl/Pages/biblio.html which
lists a paper written in 1991:

Carlton, J. T., G. J. Vermeij, D. R. Lindberg, Debby A. Carlton and E.
C. Dudley. The first historical extinction of a marine invertebrate in
an ocean basin: The demise of the eelgrass limpet Lottia alveus. Biol.
Bull. 180:72-80. 1991