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Thornhill et al . 2008. Mol. Ecol. 17 (23), 5104-5117 https://doi.org/10.15468/7a5e2q
Contact: Grant, Rachel
Availability: This dataset is licensed under a Creative Commons Attribution 4.0 International License.
Data on Antactic Nemertea. more
Open-ocean environments provide few obvious barriers to the dispersal of marine organisms. Major currents and/or environmental gradients potentially impede gene flow. One system hypothesized to form an open-ocean dispersal barrier is the Antarctic Polar Front, an area characterized by marked temperature change, deep water, and the high-flow Antarctic Circumpolar current. Despite these potential isolating factors, several invertebrate species occur in both regions, including the broadcast-spawning nemertean worm Parborlasia corrugatus.
To empirically test for the presence of an open-ocean dispersal barrier, we sampled P. corrugatus and other nemerteans from southern South America, Antarctica, and the sub-Antarctic islands. Diversity was assessed by analyzing mitochondrial 16S rRNA and cytochrome c oxidase subunit I sequence data with Bayesian inference and TCS haplotype network analysis. Appropriate neutrality tests were also employed. Although our results indicate a single well-mixed lineage in Antarctica and the sub-Antarctic, no evidence for recent gene flow was detected between this population and South American P. corrugatus. Thus, even though P. corrugatus can disperse over large geographical distances, physical oceanographic barriers (i.e. Antarctic Polar Front and Antarctic Circumpolar Current) between continents have likely restricted dispersal over evolutionary time. Genetic distances and haplotype network analysis between South American and Antarctic/ sub-Antarctic P. corrugatus suggest that these two populations are possibly two cryptic species.
Biology > Invertebrates
Marine/Coastal, Data, Dna sequencing, Marine Genomics, Rrna, PS, Antarctica, Nemertea
PS, Antarctica [Marine Regions]
1 January 2008 - 2008
Mitochondrial DNA sequences, Occurrence of biota
Based on this dataset
Thornhill, D.J. et al. (2008). Open-ocean barriers to dispersal: a test case with the Antarctic Polar Front and the ribbon worm Parborlasia corrugatus (Nemertea: Lineidae). Mol. Ecol. 17(23): 5104–5117. https://dx.doi.org/10.1111/j.1365-294X.2008.03970.x, more
Dataset status: Completed
Data type: Data
Data origin: Literature research
Metadatarecord created: 2010-08-02
Information last updated: 2019-04-09