Presentation Title

Demographic Data and Genetic Diversity of the Introduced Barnacle, Megabalanus coccopoma, in the Southeastern U.S.

Location

Atrium

Session Format

Poster Presentation

Research Area Topic:

MBI - Molecular Biology Initiative

Roundtable Presentation Participants

Gleason, D.F., Harrison, J.S.

Abstract

The barnacle Megabalanus coccopoma is a recently introduced species to the southeastern U.S. Their large body size and rapid range expansions have heightened concerns that M. coccopoma may outcompete native sessile invertebrates on hard substrata. In addition, yearly range expansions indicate the potential for local larval sources. We hypothesize that M. coccopoma populations on offshore structures are acting as a larval source and thus have higher genetic diversity and mean shell sizes than onshore populations due to overlapping generations of mature, breeding adults. To assess this hypothesis we collected demographic data including density and mean shell size from each of 4 shoreline sites and 4 offshore sites. Additionally, we sampled ~25 individuals biannually for two years from each site for genetic analysis using microsatellite markers. Demographic data supports our hypothesis indicating that offshore populations consist of larger, more mature individuals suggesting a stable adult population at these sites. To date microsatellite data shows high diversity at all sites with the mean average alleles per locus ranging from 13.15±4.83 to 18.92±7.89. All sites also show significant deviation from Hardy-Weinberg Equilibrium, which may be the result of recent founder events or a population admixture from multiple source populations.

Keywords

Introduced species, Population genetics

Presentation Type and Release Option

Presentation (Open Access)

Start Date

4-24-2015 2:45 PM

End Date

4-24-2015 4:00 PM

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Apr 24th, 2:45 PM Apr 24th, 4:00 PM

Demographic Data and Genetic Diversity of the Introduced Barnacle, Megabalanus coccopoma, in the Southeastern U.S.

Atrium

The barnacle Megabalanus coccopoma is a recently introduced species to the southeastern U.S. Their large body size and rapid range expansions have heightened concerns that M. coccopoma may outcompete native sessile invertebrates on hard substrata. In addition, yearly range expansions indicate the potential for local larval sources. We hypothesize that M. coccopoma populations on offshore structures are acting as a larval source and thus have higher genetic diversity and mean shell sizes than onshore populations due to overlapping generations of mature, breeding adults. To assess this hypothesis we collected demographic data including density and mean shell size from each of 4 shoreline sites and 4 offshore sites. Additionally, we sampled ~25 individuals biannually for two years from each site for genetic analysis using microsatellite markers. Demographic data supports our hypothesis indicating that offshore populations consist of larger, more mature individuals suggesting a stable adult population at these sites. To date microsatellite data shows high diversity at all sites with the mean average alleles per locus ranging from 13.15±4.83 to 18.92±7.89. All sites also show significant deviation from Hardy-Weinberg Equilibrium, which may be the result of recent founder events or a population admixture from multiple source populations.