World Congress of Malacology Antwerp ... - Unitas Malacologica

accumulation during the larval phase, with larvae fed only brown ride containing less lipids than
larvae fed an equal biovolume of a known good food, the alga Isochrysis. Lipids are important in
bivalves for post-metamorphic juvenile growth and survivorship, and a diet of brown tide thus may
have lasting legacies for hard clam larvae.
New insights on the phylogeny of the Conoidea (Neogastropoda) using molecular data
Puillandre, Nicolas 1,2 ; Samadi, Sarah 1 ; Boisselier, Marie-Catherine 1 ; Bouchet, Philippe 2
1. MNHN, 43 rue Cuvier, 75005 Paris, France,
Email: puillandre@mnhn.fr; dubayle@mnhn.fr; sarah@mnhn.fr
2. MNHN, 55 rue Buffon, 75005 Paris, France,
Email: pbouchet@mnhn.fr
The superfamily Conoidea is one of the most speciose groups of marine molluscs, with almost 700
genera and 10000 living species. Previous classifications were based on morphological and
anatomical characters, but clades and phylogenetic relationships were not well assessed. Informations
provided by one mitochondrial (COI) and three nuclear (28S, 18S and H3) genes were used to infer
the phylogeny of this group. Data were obtained from more than 100 specimens, belonging to 57
genera, collected during recent cruises in West-Pacific (Philippines, Vanuatu, Norfolk ridge and
Chesterfield and Salomon Islands). Some older specimens collected in West Africa were also
included in the study. Analyses were performed on each gene independently as well as for a data
matrix where all genes were concatenated, using several methods (ML, Parcimony, Bayesian). Some
families and subfamilies among Conoidea correspond to well-supported clades uniformly found with
all genes and all methods, but others appear to be polyphyletic. Several bathyal and abyssal genera
are also found polyphyletic. Our results also pointed out some new phylogenetic relationships at the
family, subfamily and genera level.
Phylogenetics of the Pectinidae: Sexual reproductive modes and the evolution of adult dispersal
behaviour
Puslednik, Louise; Serb, Jeanne
Ecology, Evolution and Organismal Biology, Iowa State University, Ames, Iowa, 50011 USA,
Email: louisep@iastate.edu; serb@iastate.edu.au
The Pectinidae is a large, cosmopolitan group of marine bivalves and includes approximately 300
species. This diversity offers a rich system to examine major evolutionary questions on the origin and
evolution of complex traits and behaviours. Within the pectinids, at least three modes of sexual
reproduction are displayed: gonochorism, hermaphroditism and protandry. Other aspects of life
history also vary within the Pectinidae, including dispersal capabilities of the adult organism. Hence,
pectinid species can be divided into six different categories based on their dispersal life history, such
as byssal attachers, cementers, nestlings, recliners, excavators or gliders. It has been hypothesized
that sexual reproductive mode may be influenced by an organism’s mode of dispersal, whereby
organisms that are highly mobile may be more likely to be gonochoristic. To test this hypothesis, we
undertook a comparative study to examine the evolutionary correlation of reproductive mode and
adult dispersal in the Pectinidae using a molecular phylogenetic framework.
A molecular phylogeny was produced for approximately 60 pectinid species using DNA sequence
from three genes: two mitochondrial (12S and 16S) and one nuclear (H3). We used both maximum
parsimony and Bayesian analyses to construct molecular phylogenetic hypotheses of the family.
Categories of sexual reproduction and dispersal life history for each species were mapped separately
onto the molecular phylogeny. We tested for correlated evolutionary change between sexual
reproductive mode and dispersal life history using the phylogenetic comparative method.
The molecular phylogeny supports previously identified tribes within the Pectinidae.
Gliding dispersal behaviour has evolved independently three times with the Pectinidae.
174