World Congress of Malacology Antwerp ... - Unitas Malacologica

Also, biomass of the seagrass (leaves and rhizomes) was quantified for each sample. The principal
aim of the study was the evaluation of the molluscan assemblage evolution along several years.
The results show the replacement of the well structured molluscan assemblage (with more than 80%
of adults and a distribution between gastropods and bivalves near to 50% each) for an assemblage
strongly dominated by bivalvian recruits (the total abundance of individuals in the last year was 87%
for recruits and 90% for bivalves). The dominant species in the assemblage were the same during the
study (genus Tellina, Mysella, Spisula and other Veneridae)
Global opisthobranch biodiversity: Are they evolving faster than we can find them?
Gosliner, Terrence
California Academy of Sciences, 875 Howard Street, San Francisco, 94103, California, USA,
Email: tgosliner@calacademy.org.
Portions of the world’s opisthobranch fauna are relatively well known, particularly the shallow
waters of the European and Mediterranean and the Atlantic and Pacific coasts of North America.
Nevertheless, examination of the chronology of the study of these faunas reveals that much of these
faunas has only recently been documented and is not yet complete. Deeper-water faunas from these
areas are far less well known than shallow-water taxa.
Other temperate areas such as southern Africa, New Zealand, Australia and Japan are far less well
known and many new taxa continue be discovered. It is likely that a minimum of 15-25 % of these
faunas remains undescribed. This view is evidenced by the number of new taxa appearing on
websites and by very recent publications describing species from these other temperate regions.
Tropical regions, with much higher diversity of taxa, remain less well-studied. Approximately, 300
species have been documented from the Caribbean, of which approximately 20% are undescribed. It
is also evident that many other Caribbean species have not yet been discovered.
The tropical Indo-Pacific is home to at least 5-10 times the diversity of species found in Caribbean.
Most localities surveyed have 16-52% of their resident species as undescribed taxa. Recent studies in
the Philippines over the last 15 years have shown that at least 40% of the species found there are
undescribed. The Philippines have more than 700 species of opisthobranchs documented from the
archipelago and species accumulation curves indicate that our knowledge of this biota is by no means
complete. Within the Indo-Pacific, most species inhabiting deeper waters, below scuba diving depths
are new taxa with possibly 90% of the species remaining undescribed. While considerable progress
has been made in recent decades to describe the world’s opisthobranch fauna, our knowledge, at
present, is far from complete.
Palaeoheterdonta MMVII: A cosmopolitan assessment of freshwater mussel diversity
Graf, Daniel L. 1 ; Cummings, Kevin S. 2
1. Academy of Natural Sciences, 1900 Benjamin Franklin Parkway, Philadelphia PA 19103 USA,
Email: graf@ansp.org
2. Illinois Natural History Survey, 1816 S. Oak Street, Champaign IL 61820 USA,
Email: ksc@inhs.uiuc.edu
Numerous issues complicate estimating the current state of our knowledge of the diversity of
palaeoheterodonts (Bivalva: Trigonioida + Unionoida): historical and contemporary supernomination
due to typological species concepts, lumped “Biological” species concepts, outmoded
higher classification, incomplete knowledge of soft-anatomical variation, and limited taxon sampling
for molecular phylogenetic studies, to name a few. These shortcomings are unfortunate given
freshwater mussels’ globally imperiled status and the potential utility of the group to lend insight to a
wide range of evolutionary processes. Based upon cladistic analysis of nuclear (28S) and
mitochondrial DNA (COI) as well as 59 morphological characters, we recovered seven
paleoheterodont families: (Trigoniidae, ((Unionidae, Margaritiferidae), ((Hyriidae, (Etheriidae,
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