World Congress of Malacology Antwerp ... - Unitas Malacologica

Malacology in the arid areas of the Middle East — unexplored or empty?
Neubert, Eike
Forschungsinstitut Senckenberg, Senckenberganlage 25, D-60325 Frankfurt am Main, Germany,
Email: eike.neubert@senckenberg.de
The arid areas of the Middle East are among those regions of the world that are least known in terms
of the presence or absence of terrestrial molluscs. On the one hand this lack of information is due to
the environmental conditions being unsuitable for terrestrial molluscs, but on the other hand it is the
result of the poor scientific exploration.
Information compiled from the available literature concerning species richness, taxonomical
structure, endemism and biogeographical background of the area is presented. Numbers illustrating
the present state of knowledge are given supplemented by estimates on the numbers of species that
can be expected. Results show that the arid areas of the Middle East represent an undersampled
region, where a considerable increase of species numbers can be expected. The lack of records
mainly dates from the era of the ‘Golden Age of Malacology’ between 1800–1890, when interest was
focused on more easily accessible areas, while the Middle East was more or less ignored. Thus, an
enormous gap in knowledge persists until today.
Unfortunately, recent efforts in inventorying the malacofauna of the world, such as checklists and
databases, continue to disregard this malacofauna. An inventory reflecting the true composition of the
malacofauna is impeded by the following factors: the enormous backlog in cataloguing historical
material present in major museums, the information widely scattered in literature, the unsatisfactory
state of present taxonomical concepts, the disregard of species-level taxonomy, and others.
Additionally, the traditional approach towards biology in the countries concerned is more focused on
applied questions such as parasitology and similar subjects. The importance of inventories or of
surveys on biological diversity as tools for conservation strategies is not fully accepted until today.
Opisthobranchs go limnic: comparative 3D microanatomy of the marine interstitial acochlidian
Pseudunela and the freshwater Strubellia from Vanuatu
Neusser, Timea P.; Schrödl, Michael
Zoologische Staatssammlung München, Münchhausenstr. 21, 81247 München, Germany,
Email: timea-neusser@gmx.de; schroedl@zi.biologie.uni-muenchen.de
Uniquely among the otherwise marine opisthobranchs, several acochlidian species are known to
inhabit true freshwater systems. Our histological re-examination of the Caribbean mountain spring
swamp dweller Tantulum elegans Rankin, 1979 revealed severe discrepancies to its original
description, but its systematic position remained unresolved. The present study tries to explore the
secrets of an array of limnic acochlidian species that are distributed over several tropical Indo-Pacific
islands. The internal anatomy of a limnic Strubellia species from Espiritu Santo, Vanuatu is 3dimensionally
reconstructed from serial histological slides using AMIRA software. For an in-depth
structural comparison with a marine species, the poorly known mesopsammic Pseudunela cornuta
(Challis, 1970) is redescribed from Vanuatu specimens in greatest possible detail. The potential
origin of Indo-Pacific limnic species from a Pseudunela-like marine ancestor is discussed and
evolutionary pathways towards successfully colonizing limnic habitats are highlighted.
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