Fabio,

The mechanism of color production in the shells of mollusks has not been
fully determined; however, it is interesting to note that several species of
Oliva will reflect the color of their environment,
Examples are Oliva jaspidea and Oliva panniculata. These may be black or
dark from the areas of black sand and white from areas with white sand.
Ed Petuch and I feel that there is something in the environment that affects
the production of color in the shells. Tursch and Greifeneder established
the theory they called "local color palette" based upon areas where several
species of Oliva were found together and exhibited similar color and
patterns. We have been looking for answers and only finding more questions.
But that is what science is all about!

Best wishes,

Dennis Sargent

________________________________________
From: Conchologists List [mailto:[log in to unmask]] On Behalf Of
Fabio Moretzsohn
Sent: Friday, February 27, 2009 11:40 AM
To: [log in to unmask]
Subject: Re: [CONCH-L] Albino Shells

I wonder if there are environmental conditions that may induce or influence
mollusks to produce less melanin than normal, resulting in lighter-colored
shells (not true albinos), kind of the opposite of some places known for
melanistic shells, like Prony Bay in New Caledonia, where specimens of many
species of cowries can be found. It is assumed that higher levels of nickel
in the water may contribute to some specimens (but not all) producing more
pigments to the point that some shells become jet black (some also become
very rostrate and distorted).

So, could this place mentioned by Peggy have some environmental conditions
that inhibits the production of pigments in some mollusks?

The practice of cooking shells in oil to produce fake albinistic shells that
Andrew mentioned is well known. I wonder if there is any known process to
produce darker shells, or even to change the colors to different hues?

Fabio M.

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