Lip-tingling and tongue-tingling are also an indication of "red tide" or paralytic shellfish poisoning, which definitely could be in your Macomas.
Roland
 
Roland C. Anderson, Puget Sound Biologist
The Seattle Aquarium
1483 Alaskan Way
Seattle WA 98101 USA
phone: 206-386-4359
See our website: www.seattleaquarium.org
 
>>> Ross Mayhew <[log in to unmask]> 12/10 6:11 AM >>>
    Sorry for cross-posting this brief message (and repeating, but i did
not recieve any plausible replies the first time!) , but there are new
members recently who may have the answer to this little mystery. Also,
it would be interesting to hear about unusual defence methods that
seemingly-innocent bivalves use to avoid being eaten!
 
<While we are on the topic of lip-tingling sensations caused by
molluscs, i'll add my 2 cents' worth.  Macoma calcarea seems to be
capable of defending itself by producing either a toxin, or perhaps an
electrical discharge, although i have not found any reference to this in
the literature.  When picking up shells on scallop trawlers, i sometimes
pop them in my mouth for temporary storage (like a chipmunk!), since a
container on the sorting table would be upset quickly.  Once i did this
with a Macoma calcarea, and recieved  what felt like the tingling one
recieves when testing a battery with one's tongue.  I have never heard
of a similar report, but would be quite interested to know if other
bivalves have this type of defence mechanism!!>
 
-Ross M.