World Congress of Malacology Antwerp ... - Unitas Malacologica

adula were found as well as species with a rather distinct radula irrespective of substrate. Two
species are highly variable both in shell and trophic morphology, even within populations on one
substrate. These findings are consistent both with the assumption of intraspecific polymorphism or
possible incipient speciation. Molecular phylogenies based on mtDNA data and nuclear AFLPs were
used to test these hypotheses and the validity of morphological species delineations in general. While
the mtDNA data fail to support even a single morphospecies, the results from the AFLPs are
generally in concordance with the morphological findings and provide evidence for fine-scaled
differentiation and possible speciation in one case. The discordance between the two molecular data
sets also suggests that introgressive hybridization might be a common factor in this system. Simple
models of diversification do not seem sufficient to explain the observed diversity in this ancient lake
species flock.
On the identity of two New World ampullariids, Pomacea lineata and Pomacea figulina
Thiengo, S.C. 1 ; Hayes, K. 2 ; Mattos, A. 1 ; Fernandez, M.A. 1 ; Cowie, R.H. 2
1. Laboratório de Malacologia, Instituto Oswaldo Cruz/Fiocruz, Av. Brasil 4365 Manguinhos 21040-
900 Rio de Janeiro, RJ, Brasil,
Email: sthiengo@ioc.fiocruz.br
2. University of Hawaii – Manoa, Center for Conservation Research and Training, 3050 Maile Way,
Gilmore 408, Honolulu, HI 96822, USA,
Email: cowie@hawaii.edu
Ampullariids are freshwater snails distributed throughout the tropical regions. They are represented
in the New World by five genera: Asolene (7 spp.), Felipponea (3), Marisa (2), Pomella (3) and
Pomacea (~ 50). The taxonomy and evolutionary relationships within Pomacea are still confused in
spite of its abundance, wide distribution and importance from biological, parasitological and
economic points of view. This study is part of a collaborative project aimed at a taxonomic revision
of New World ampullariids based on morphological and molecular studies. Pomacea figulina was
illustrated by Spix as a full species but when Spix’s illustration was published by Wagner (1827) the
latter treated it as a small variety of P. lineata. It has since been considered a synonym of P. lineata
by many authors. However, examination of the types of both species at the Zoologische
Staatssammlung München revealed that the shells are quite different. In addition, data from
morphological and molecular studies on specimens of both species collected in Brazil confirmed their
distinction. Pomacea lineata has a more elongate shell with a wide umbilicus and the penial sheath
has a prominent outer basal gland and concave tip, while P. figulina is more globose, the shell is
almost imperforate and the penial sheath has two inner glands and a rounded tip. Supporting the
morphological distinctiveness, phylogenetic analyses of mitochondrial and nuclear sequences places
the two species into reciprocally monophyletic groups. The distribution of the two species overlaps
and we have collected specimens from six states from the northeast, southeast and Midwest regions
of Brazil.
The nervous system of Solenogastres – a confocal view
Todt, Christiane 1 ; Wanninger, Andreas 2
1. University of Bergen, Department of Biology, Thormøhlensgate 55, P.O. Box 7800, N-5020
Bergen, Norway, Email: Christiane.Todt@bio.uib.no
2. Institute of Biology, Department of Cell Biology and Comparative Zoology, Universitetsparken
15, DK-2100 Copenhagen, Denmark,
Email: awanninger@bi.ku.dk
Even though the nervous system has been considered to provide important characters for mollusk
systematics and phylogeny for many decades, the plesiomorphic type of the molluscan nervous
system is still under debate. The Solenogastres (or Neomeniomorpha) are, together with the
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