>Dear members of the list:
>I am looking for examples of sibling species belonging to different
>families of molluscs. I mean valid  species of molluscs, which have
>practically indistinguishable shells and  their taxonomic identity
>is clearly established by non-conchological method (or methods).
>Today, I know only one example when malacologists think that two
>different valid species have very similar (almost identical) range
>of distribution and extremely similar  (until now,
>indistinguishable) shells  and are considered valid species --
>Cypraea teres and Cypraea alisonae. Knowing about a similar
>situation in other families of molluscs can help us to better
>understand this phenomenon.
>Apropos, perhaps use of a term "sibling species" in this case is not
>suitable because in the Webster's Third New International Dictionary
>(1976) one can read:"sibling species: one of two or more physiologic
>races that are morphologically nearly or completely
>indistinguishable."  This sentence defines, perhaps, subspecies
>rather than species.
>
>Eduard Heiman
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>
>

Cryptic species. They look identical and may have identical
anatomies, but DNA work and ecological studies (say distinctly
different breeding times) will separate them. Useless to the
collector, though, as he has NO way to distinguish them, and any
accurate label/catalog then must list the alternative ID!

Anodonta in Newfoundland
Littorina saxatilis & cryptic species (see Reid ?1992)
Utriculastra and Acteocina
--
Andrew Grebneff
165 Evans St, Dunedin 9001, New Zealand
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Seashell, Macintosh, VW/Toyota van nut