World Congress of Malacology Antwerp ... - Unitas Malacologica

their habitats and diverse anatomical features, in order to demonstrate the unrevealed diversity of
micromolluscs in this area.
A molecular phylogeny of the Buccinidae—a southern and a northern connection
Hayashi, Seiji
Graduate School of Environmental Studies, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-
8601, Japan,
Email: seijih@nagoya-u.jp
The Buccinidae comprises one of the most prolific families among the Neogastropoda, with fossil
records back into the Cretaceous. There has been marked adaptive radiation of the family, with a
distribution ranging from equatorial to polar regions and from fresh water systems to deep ocean vent
communities. However, the phylogeny of the family remains ambiguous. There is no consensus as to
its taxonomic boundaries, or to the relationships among its genera and subgenera. To address these
problems and mainly to identify major phylogenetic groups within the Buccinidae, sequences of the
entire mitochondrial 12S and 16S rRNA genes for 45 caenogastropods (including 34 buccinoids)
were collected for molecular phylogenetic analysis. This used the conserved (unambiguously aligned)
regions of both genes using a Bayesian approach.
The resultant 95% majority-rule consensus Bayesian inference tree revealed monophyly of the
Buccinoidea with high statistical significance, yet the initial radiation of the superfamily could not be
resolved fully. In contrast, monophyly of the Buccinidae in the traditional sense—except for
Babylonia—was not supported; however, this could reflect the inadequate level of resolution of the
current dataset. Of polytomously branched clades under the Buccinoidea, most noteworthy is a
subordinarily structured clade that accommodates both boreal and Austral genera. This suggests some
ancient vicariant or dispersal process across the equator in an early stage of buccinid evolution. For
future research, supported clades, as well as unresolved radiation in the present results, need further
evaluation with denser taxonomic sampling and additional gene sequences.
Molecular systematics and evolutionary patterns of diversification in New World
Ampullariidae
Hayes, Kenneth A.
Department of Zoology, University of Hawaii Manoa, Honolulu, Hawaii 96822, USA,
Email: khayes@hawaii.edu
Apple snails (Ampullariidae) are freshwater, operculate snails globally distributed in humid tropical
and subtropical habitats. Nine genera are recognized: Afropomus (1 species), Saulea (2) and Lanistes
(~20) are African; Pila (~30) is African and Asian; Asolene (7), Felipponea (3), Marisa (2) and
Pomella (3) are South American; Pomacea (~50) ranges from Argentina to the southeastern USA.
Ampullariid taxonomy and evolutionary relationships remain poorly understood, especially regarding
Pomacea, which has implications for research on many aspects of ampullariid evolutionary biology.
Here I provide a preliminary phylogenetic basis for addressing questions of Neotropical ampullariid
diversification. Samples were collected from ~190 populations in South and Central America,
concentrating in Brazil, the center of ampullariid diversity. Phylogenetic analyses of mitochondrial
and nuclear loci from 44 species (>1000 snails) in 7 genera indicate that New World Ampullariidae
are a robustly supported monophyletic group with respect to Old World ampullariids. Within this
group most species of Asolene, both Marisa species, and Felipponea neritiformis form a basal,
weakly supported polyphyletic clade, sister to a weakly supported group of species currently placed
in Pomacea and Asolene. Most Pomacea spp. cluster into four distinct groups, with 11 and 7 in the
“canaliculata group” and “bridgesii group”, respectively. Six species ranging from the Amazon Basin
through Venezuela constitute the “glauca group” and 5 from South and Central America are in the
“sordida group”. Overall, these results confirm what conchology has always hinted at: New World
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