Dear John,

Greetings from the AMS meeting in Ithaca. Your point about vouchers is well taken. We have been working away at providing images of all the shells of Conus specimens my group has sequenced, on Chris Meyer's ftp site at FLMNH. It's presently incomplete, but Chris is working on completing it. I just sent him images of about a dozen shells of sequenced specimens that I had in my lab.

When I return I'll check on the C. centurio-C. delessertii-? problem that you mentioned. I had noticed it before but had not done anything about it.

Alan


On Sat, 18 Jul 2009, John Tucker wrote:

> Dear Alan,
>
> Your work is good and of course I appreciate the information that
> molecular studies provide.  However, these studies are valid when there
> are differences to be found.  In the case of Melongena corona (sensu
> lato) the molecular study was uninstructive.  This could be because
> there are no differences or because the genes chosen were not the ones
> that would help.
>
> I also might mention a real problem with molecular studies is the lack
> of conchological vouchers.  Now all of the these sequences are in a gene
> bank but the molecular scientists seem to have little concept as to what
> they are calling what.  I point out an example from Duda & Kohn, 2005
> (Molecular Phylogenetics and Evolution 34:257-272).  An entity
> identified as Conus centurio grouped with a number of other western
> Atlantic species (C. daucus, C. poormani, and C. villepinii, Figure 1,
> the 16S phylogram).  All we know is that this specimen is Genbank
> accession number AY382002.  I can say that this particular sample is not
> C. centurio.  C. centurio is closely related to C. delessertii.  These
> are possibly part of a single polytypic species.  Conchologically, they
> are about identical excepting coloration.  Their radulae are identical
> and both have the same structures on the anterior end of the tooth
> including a barb, blade, and posterior blade.  These structures occur in
> C. delesserti and in other small major clade species.
>
> I expect that the shell identified as C. centurio was really C. sanderi
> or some other large major clade species.  So far as I can tell I have no
> way to find out what AY382002 actually looked like.  This to me is a
> weakness in the use of sequences from snail with no vouchered
> conchological specimen.
>
> Finally, I have a comment on Melongena corona.  I have been somewhat
> amazed by the some of the comments made in the past.  Has anyone
> actually read Florida Museum of Natural History Bulletin 36(7) where I
> described M. sprucecreekensis?  The species was not founded on its large
> size but on comparisons of meristic traits using analysis of
> covariance.  In fact, I did all that I could statistically to remove
> size as a variable.  Some spoke of the need for gaps in the linear array
> of populations that Melongena forms.  The paper points out two such
> breaks in shell morphology.  One is at Cedar Key where the Suwannee
> River enters the Gulf and the other is in the Florida Bay.  These are
> illustrated in Figure 2.  johnstonei and corona do intergrade but the
> intergrade zone is narrow and distinct.  Morphologically there is no
> real evidence of an intergrade zone between bicolor and sprucecreekensis
> or for that matter bicolor and corona.  I thus prefer my original
> hypothesis of three species on the Florida coast.  The molecular
> evidence may not be there yet but the morphological evidence is sound.
> Citing one variant after another as proof my hypotheses are wrong is
> less than useful.  Tell me how many spines the population has and
> present ANCOVA demonstrating where the POPULATION fits would be more
> meaningful.
>
> Yours,
>
>
>
> John K. Tucker
>
>
>
> John K. Tucker
>
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