World Congress of Malacology Antwerp ... - Unitas Malacologica

A molecular phylogeny of apple snails (Gastropoda: Caenogastropoda: Ampullariidae) with
emphasis on the African species
Jørgensen, Aslak; Kristensen, Thomas K.; Madsen, Henry
Mandahl-Barth Research Centre for Biodiversity and Health, DBL - Centre for Health Research and
Development,Department of Veterinary Pathobiology, Faculty of Life Sciences, University of
Copenhagen, Jægersborg Alle 1D, 2920 Charlottenlund, Denmark,
Email: aslak@life.ku.dk; tkk@life.ku.dk; hmad@life.ku.dk
Ampullariids are widespread in Africa, Asia and South and Central America. Between 7 and 10
genera are currently recognized depending on the authority. A basal phylogenetic relationship of the
African genera Afropomus and Saulea has been inferred based on anatomical evidence. Until recently
the Viviparidae was believed to be the sister-group of Ampullariidae but recent molecular data infer a
sister-group relationship with Campanilidae. We have used members of both families as outgroups in
the present investigation on ampullariid phylogeny. We have used data from five molecular loci i.e.
the nuclear genes 18S rRNA, 28S rRNA and H3 and the mitochondrial genes 16S rRNA and COI.
Our preliminary data most often infer a basal position of Afropomus. The position of Saulea is more
ambiguous being inferred both as the second most basal taxon but also as a member of a clade
including the South American Marisa and Pomacea. The African genus Lanistes is inferred to be
paraphyletic by the conserved 18S and 28S, but form a clade when H3 and 16S are analysed. COI
also infer paraphyly, but this gene show evidence of beginning substitutional saturation. The African
and Asian genus Pila is most often inferred to be monophyletic (except for 28S). A sister-group
relationship is most often inferred between Lanistes and Pila. The species radiation of Lanistes in
Lake Malawi did only show 0.64% and 1.22% sequence variation in COI and 16S, respectively,
between Lanistes ellipticus, L. nyassanus and L. solidus. This suggests that the morphological
divergence has happened much faster than the molecular divergence.
Sex in the beach: reproduction of the aphallic, interstitial Pontohedyle milaschewitchii
(Acochlidia, Opisthobranchia)
Jörger, Katharina M. 1 ; Heß, Martin 2 ; Schrödl, Michael 1
1. Zoologische Staatssammlung München, Münchhausenstr. 21, 81247 München, Germany,
Email: k_joerger@hotmail.com; schroedl@zi.biologie.uni-muenchen.de
2. Department Biology II of the Ludwig-Maximilians-Universität München, Großhaderner Str. 2,
82152 Planegg-Martinsried, Germany,
Email: hess@zi.biologie.uni-muenchen.de
Within the opisthobranchs external sperm transfer via spermatophores is very unusual and knowledge
on the structure of opisthobranch spermatophores and the insemination following the placement of
the spermatophores on the body wall is scarce. The mainly minute and interstitial Acochlidia are
known for an extraordinary reproductive life, such as for the occurrence of gonochorism, the
remodelling up to complete reduction of the male copulatory organs, and for the development of
different modes of sperm transfer: by copulation, by hypodermic injection and via spermatophores.
Spermatophores in Acochlidia are known from the gonochoristic Microhedylidae, the hermaphroditic
Asperspinidae and are also suggested for at least one likewise aphallic species of the hermaphroditic
Hedylopsidae.
The ultrastructure of spermatophores and spermatozoa of the microhedylid Pontohedyle
milaschewitchii (Kowalevsky, 1901) were studied using transition electron microscopy (TEM).
Spermatozoan morphology was reconstructed 3-dimensionally from ultrathin serial sections using
AMIRA software. The movement of the spermatozoa during the discharge of the spermatophore
could be observed directly under the fluorescence microscope using DAPI-staining of the nuclei.
Spermatophores of P. milaschewitchii were placed indifferently on head-foot complex and visceral
hump of the counterparts (including other males and immature specimens). The discharge of the
spermatophore lasted various hours. The spermatozoa were observed moving actively and
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