World Congress of Malacology Antwerp ... - Unitas Malacologica

Pupilla muscorum (Linnaeus, 1758) is the most widespread species in the genus Pupilla. The species
is highly variable and rich in forms. The taxonomic identity of one of these forms, var. pratensis
(Clessin, 1871), commonly considered an ecophenotype of wet habitats, has been investigated using
morphological, ecological and molecular data. The forms differ in a row of morphological characters,
pratensis being larger, more thin-shelled, and having a toothless aperture. They separate well also
using molecular data (COI and CytB) and hence, we conclude that the two forms represent distinct
species. Pupilla pratensis shows some resemblance to the high alpine taxon Pupilla alpiola
(Charpentier, 1837), but differs distinctly in some morphological characters. P. pratensis is
pronounced hygrophile, occurring in calcareous fens. It was described from Germany and also occurs
in Poland and the Czech Republic. It is distributed almost throughout all of Scandinavia. A wide, but
scattered distribution, mainly in calcareous areas in central, north (and possibly western) Europe is to
be expected.
The underused combined approach (morphology, ecology and DNA-barcoding) proves to be a
powerful tool in distinguishing among closely related species within the genus Pupilla. We suggest
that combined results from several methods should be used before assigning taxonomic identity and
when sorting out complexes in other taxonomic groups as well.
Approaches and problems in species delimitation of tropical freshwater snails: examples from
Southeast Asian pachychilids
von Rintelen, Thomas; Köhler, Frank; Glaubrecht, Matthias
Museum of Natural History, Humboldt University Berlin, Invalidenstrasse 43, 10115 Berlin,
Germany,
Email: thomas.rintelen@museum.hu-berlin.de
The destruction of freshwater biota and the loss of habitats is particularly dramatic in Southeast Asia.
The region has rich endemic assemblages of limnic molluscs, especially prosobranch gastropods, and
their inventorization is a prerequisite for the conservation of freshwater diversity. We here employ
data from the endemic and speciose Southeast Asian genera of the cerithioidean Pachychilidae to
illuminate issues arising from using classical morphological and recent molecular methods such as
DNA barcoding in the process of species delimitation and diversity assessment.
We used traditional morphological characters such as the shell or radula in the initial delimitation of
pachychilid species. This procedure proved straightforward in sympatric situations, which were then
employed as a benchmark against which species status could be estimated in allopatric situations.
This approach revealed a considerably higher number of putative species than previously described,
mostly endemics with a restricted occurrence. The taxa delineated by this method did show a poor
match to genetic units derived from a molecular phylogeny based on mtDNA, though. The high level
of congruence among different morphological characters and geography indicates that this rather is a
problem inherent to properties of the mtDNA markers than reflecting errors in prior species
delimitation or cryptic species.
The widespread mismatch between species hypotheses derived from morphological and molecular
data even among sympatric taxa suggests that a mere ‘barcoding shortcut’ is not applicable in
diversity assessment in these freshwater gastropods, which are probably representative for many
tropical limnic caenogastropods. While sequencing may fail in facilitating easy species recognition,
estimates of genetic diversity remain nevertheless valuable. In allopatric situations, which constitute
the majority of cases, species delimitation remains ambiguous, since our molecular data indicate that
even a high genetic distinctiveness may not be correlated with reproductive isolation. Species
diversity estimates will have to take account of that intrinsic uncertainty.
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