Dear Victoriano,
Looking over the Philippine literature it would be easy to say that the
many names used in Ryssota are merely forms of a very few widely
distributed species.  That is, until one goes there and actually collects
specimens.  Most of the populations which have names are very discreet and
adhere to biogeographic patterns seen in more well-known groups, such as
reptiles, birds, etc.

Unfortunately, there is no way to say now whether ovum is distinct at the
species level.  It may be a subspecies, maybe a species....no one knows at
this point as not enough collecting has been done.  All I can say right now
is that typical ovum is distinct in shell morphology from typical
otaheitana.  But many more localities need to be collected and additional
anatomic studies are required to sort out this problem.

You can find illustrations of both taxa at G. Poppe's webpage .....go to
old books (or something like that), click on Hidalgo's Obras Malacologicas,
you can find the illustrations in there......Wish I had time to discuss
this in more detail.....But if I get started on PI land snails, it will
take days to stop myself.....

Kurt

At 02:09 PM 1/29/02 -0500, you wrote:
>Dear all I have threes questions so I have written 3 emails to the
>Conch_L users.
>
>  I have some shells that Paul Monfils clasificated me (from here I want to
>thank you, I know this will arrive in your email too) in this Url:
>http://www.seashell-collector.com/identification/other.htm like "Ryssota
>otaheitana Ferussac, 1821, from Luzon Province, Philippines. A commonly
>seen synonym is Ryssota ovum (Valenciennes, 1854). The family is
>Helicarionidae". To confirm this (I´m a bit touchy) I have looking for a
>picture or photograph in the net, but I didn´t find it. The only thing that
>I have found is that there some subespecies:
>
>Ryssota otaheitana A. de Férussac, 1821 Philippines
>Ryssota otaheitana demesai P. Bartsch, 1938 Philippines
>Ryssota otaheitana depressa O. F. von Möllendorff, 1898 Philippines
>Ryssota otaheitana ovum Valenciennes, 1827 Philippines
>Ryssota otaheitana samarensis P. Bartsch, 1938 Philippines
>Ryssota ovum Valenciennes, 1854 Indo-Pacific
>
>
>so I need your help about these new questions:
>
>-- Ryssota otaheitana and Ryssota ovum are the same or different species?
>-- Or is Ryssota ovum a subspecies of Ryssota otaheitana?
>-- What are the differences between the subspecies? I want to have the
>rightest name like ever.
>
>
>Thanks to all in advance.
>
>
>                              Victoriano, Cádiz, España (Spain)
>
>e-mail: [log in to unmask]
>Url: www.eureka.ya.com/aaaron25
>
Mr. Kurt Auffenberg
Senior Biological Scientist
Exhibits & Public Programs
University of Florida
Hull Road & SW 34th Street
Powell Hall, P.O. Box 112710
Gainesville, Florida 32611-2710

Telephone: 352-846-2000, ext. 253
Fax:  352-846-0253