A number of species in Hawaii vary in rarity with time:  Cypraea
granulata is in this category.  Some years it is near to rare.  Some
years, if you know where they are to be found, you can find 3 or 4 in
two dives in a good area.
 
C. granulata is essentially endemic to Hawaii.  This alone would limit
the total number ever available to people outside Hawaii.
 
There are a relatively small number of divers in Hawaii that collect
shells, and the number is decreasing due to ecological concerns.  This
means they will be harder to obtain in the future.
 
There are fewer people in Hawaii that trade shells than formerly, and
the number was always small.  This, again limits the number of C.
granulata and other Hawaii endemic shells available off the island.
 
I maintained records of all species seen while diving for about 18 years
diving in Hawaii.  (For obscure reasons, I didn't maintain the log for
about 3 years when C. granulata was more common)  My log shows seeing C.
granulata at 30 stations during that time, and the number seen varied
from 1 to 4.  Of course, the majority of my 1950 stations were not in
areas where I expected to see C. granulata.
 
In total, C. granulata are not common to people out of Hawaii. and the
same applies to other endemic species that are more common or less
common than C. granulata.
 
The same availability of shells found in Hawaii, but not endemic to
Hawaii applies.  If you want a specimen of a shell from Hawaii that is
rare in Hawaii but common elsewhere, it would have to be treated as rare
 to a collector outside Hawaii.
 
This rarity of specimens from a specific area applies to all areas. If
the area is small and remote, and the species rare there, and collectors
are few, getting a specimen from that area is difficult.
 
--
                     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
       http://www.hits.net/~hsn                 [log in to unmask]