There have been a number of instances of isolated specimens of a Cypraea
species being found in Hawaii.  I hadn't heard of the C. boivinii.  the
majority of isolated species center near the entrance to Pearl Harbor
where there is some ship traffic from Guam and other points.  Barges and
ships that were anchored in Guam for a long period and had considerable
growth on the hull had non-Hawaiian species attached.  Their towing
speed probably allows that.

Another source of unique species is the off loading of ballast water
prior to entering harbor.  The ballast water can easily contain veligers
when on loaded, and could easily survive a relatively short transit.

I found one Cypraea and my dive partner found another that were
one-of-a-kind here.  Others are reported each year.  Most do not become
established.  Cypraea moneta are very scarce but have become established
in several places in Hawaii.  Oddly, Cypraea annulus has not been found
in Hawaii although both it and C. monetta are common in many Pacific
ports.

C. erosa have been found as fossils here so they were present at one
time, but became extinct in most places, though a few have been found in
Maui.  This early presence and current absence is true of several
species.

Incidently, I know of no niger Cypraea in Hawaii.  Some other families
have very dark shells occasionally.
--
                     Aloha from Wesley M. Thorsson
Editor of Internet Hawaiian Shell News, a monthly Internet Publication
           122 Waialeale St, Honolulu, HI  96825-2020,  U.S.A
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