The CITES convention designates spp as "endangered" (even though some
are not really- it is a bit of a political football at times!!), and is
***completely illegal*** to transport any of these spp across
international borders- if caught, the penalties can be rather stiff
(they vary from country to country, however), so it is good advice not
to even THINK of doing so.
        For those who do not wish to navigate the entire CITES website, here is
the page for molluscs: http://www.wcmc.org.uk/cgi-bin/anap97.pl
(attatched).  You will note many are Unionids (fresh-water clams), which
often have a rather limited range (sometimes a single watershed!!), so
can be threatened easily by  industrial pollution, farm runoff,
siltation (such as from clear-cutting and poor farming practices), and
municipal sewers.  The entire Tridacnidae clan ("giant clams") seems to
have been included to protect Tridacna gigas (although why anyone would
wish to import/export quantities of the juveniles of this species is
beyond me!!),  and the famous "green snail" (P. pulcherissima
(spelling?)) is not really that rare either- it usually occurs higher in
the trees than most people care to look, so it was erroneously thought
to be "endangered", by people who were not looking in the right places
(someone PLEASE correct me if i have this wrong- it is a third-hand
story (albiet an interesting one!!), so it could be as bogus as the
concept of "military intelligence"!!).  The list most probably includes
only a tiny fraction of the land and fresh-water species endangered
worldwide, since few authoritative srudies are being done on this
subject recently.  However, marine spp are seldom truly in major danger
(Tridacna gigas excepted!!), since they usually have large ranges, and
while local populations may be endangered or eradicated, any given
species of marine mollusc is quite difficult to  threaten throughout its
range.
        The species on the list whch is MOST mysterious is Strombus gigas- the
"queen conch".  Although some local populations, especially in Florida,
are greatly over-collected, the species as a whole is about as
endangered as the common House Cat!!  Can someone please explain why the
queen conch is on the CITES list??
                                                                                                                                                        -Ross M.