Meeting Abstract
The neogastropod family Columbellidae is a highly successful group of small epibenthic marine snails, with 725 living species in 69 nominal genera distributed in temperate to tropical waters worldwide. Extensive polymorphism has caused the establishment of a plethora of names currently treated as synonyms. Although columbellids can be found from the intertidal to depths of 2,000 meters, maximum diversity is in shallow tropical habitats; 40 to 50 species can co-occur at single West Pacific sites, with syntopic occurrences of up to 10 to 12 species. Species vary widely in habitat, diet, larval development and adult anatomy, and provide many potential avenues for studying macroevolutionary trends. Membership in the family is traditionally confirmed using the unique morphology of the radula and, as in all shelled gastropods, species are typically defined and identified by conchological characters. The monophyly of the group and its constituent genera have never been rigorously tested. To reconstruct columbellid phylogeny, we assembled a data set including five mitochondrial and nuclear gene markers, for multiple representatives each of over 80 species in 25 genera and representative outgroups from the buccinoid and muricoid neogastropods. Correspondence of the resulting phylogeny with the traditional classification based on anatomical and morphological data will be assessed. Preliminary results based on partial data for three markers suggests that Columbellidae as it is understood based on the unique radular morphology is monophyletic, but traditional subfamilies based on radular morphology, anatomical data and conchological characters are not. In addition, several nominal genera based primarily on conchological characters such as the presence or absence of axial sculpture are polyphyletic.
