World Congress of Malacology Antwerp ... - Unitas Malacologica

heterogeneity. The values of the diversity indexes were very close, on both sides, slightly higher at
the oceanic side. Accumulation curves showed that samples were not enough. Jackknife richness
estimator indicated 29 to 41 species to the oceanic side and 34 to 51 species to the continental. The
cluster analysis identify three similar biological groups: one at 100m, other at 200m, another joining
the 300, 400 and 500m altitudinal level. The most important factors explaining snail distribution, on
the two sides were humidity, atmospheric and soil temperature and litter depth; on the continental
slope brightness and canopy closure also influenced the distribution of the snails. With this work, the
land snail richness of Grande Island reaches 62 species.
Are morphological and molecular perspectives of anomalodesmatan phylogeny reconcilable?
Sartori, André F.; Harper, Elizabeth M.
Department of Earth Sciences, University of Cambridge, Downing Street, Cambridge, CB2 3EQ,
UK,
Email: andrefsartori@yahoo.com.br; emh21@cam.ac.uk
In recent years, the use of molecular techniques in studies of bivalve phylogeny has revolutionized
our understanding of the relationships among several taxa. Based on molecular evidence, the
ecologically diverse Anomalodesmata has been reclassified as an order of basal heterodonts instead
of as a subclass of its own. Traditional views of internal anomalodesmatan relationships have also
been challenged, with several families and superfamilies widely accepted as monophyletic on
morphological grounds being rendered strongly as non-monophyletic in molecular surveys. Such
incongruence between these two sources of data might indicate that convergent evolution of
morphological traits has been so common in the group as to mask phylogenetic signal. Alternatively,
at least part of the conflicting results may be due to misinterpretation of homologies and insufficient
knowledge of the morphological variation within each nominal family. If the latter is the case,
increasing the number of taxa and morphological characters sampled in previous cladistic analyses
should resolve the issue and clarify what derived character states are shared by the clades supported
by molecular studies. To test this hypothesis, a cladistic investigation based on morphological data is
in progress, comprising previously unsampled anomalodesmatan genera and characters, as well as a
reinterpretation of traits used in previous studies. A preliminary analysis of this dataset is presented.
Micromolluscs in Japan: recent findings and future subjects
Sasaki, Takenori
The University Museum, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033,
Japan,
Email: sasaki@um.u-tokyo.ac.jp
Studies of micromolluscs are essential in the malacology of the 21st century. Our understanding on
molluscs has been chiefly based on large-sized species, but there are many little-known taxa
composed only of small-sized species. Obviously high-quality research focusing on micromolluscs
must be accelerated in various fields, especially in species-level taxonomy, comparative anatomy,
and molecular phylogeny. In taxonomic studies, species diversity is extremely high in Gastropoda
and Bivalvia, and undescribed small species also exist in other classes. In Japan, more than 8000
species of molluscs have been recorded since 18th century, but there are still numerous (more than
1000?) unidentifiable or undescribed species. For anatomical and molecular studies, obtaining fresh
material is particularly important. Live micromolluscs can be collected almost everywhere by
standard methods like sediment screening and rock washing, but some specific groups had been
known only as empty shells. New findings since the late 1990s suggest that we have to pay attention
to all possible environments, including undersides of half-buried boulders, deep crevices in rocks,
submarine caves, sunken drift wood, chemosynthesis-based biological communities, underground
freshwater, etc. Developmental and life-history studies are also necessary to establish identification
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