Limited contemporary gene flow and high self‐replenishment drives peripheral isolation in an endemic coral reef fish |
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Authors: | Martin H. van der Meer John B. Horne Michael G. Gardner Jean‐Paul A. Hobbs Morgan Pratchett Lynne van Herwerden |
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Affiliation: | 1. Molecular Ecology and Evolution Laboratory, Australian Tropical Sciences and Innovation Precinct, James Cook University, , Townsville, 4811 Australia;2. School of Marine and Tropical Biology, James Cook University, , Townsville, 4811 Australia;3. ARC Centre of Excellence for Coral Reef Studies, James Cook University, , Townsville, 4811 Australia;4. School of Biological Sciences, Flinders University, , Adelaide, 5001 South Australia, Australia;5. Evolutionary Biology Unit, South Australian Museum, , Adelaide, 5000 South Australia, Australia;6. The Oceans Institute and School of Plant Biology, University of Western Australia, , 6009 Australia;7. Australian Institute of Marine Science, , Perth, 6009 Western Australia, Australia;8. Centre for Sustainable Tropical Fisheries and Aquaculture, James Cook University, , Townsville, 4811 Australia |
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Abstract: | Extensive ongoing degradation of coral reef habitats worldwide has lead to declines in abundance of coral reef fishes and local extinction of some species. Those most vulnerable are ecological specialists and endemic species. Determining connectivity between locations is vital to understanding recovery and long‐term persistence of these species following local extinction. This study explored population connectivity in the ecologically‐specialized endemic three‐striped butterflyfish (Chaetodon tricinctus) using mt and msatDNA (nuclear microsatellites) to distinguish evolutionary versus contemporary gene flow, estimate self‐replenishment and measure genetic diversity among locations at the remote Australian offshore coral reefs of Middleton Reef (MR), Elizabeth Reef (ER), Lord Howe Island (LHI), and Norfolk Island (NI). Mt and msatDNA suggested genetic differentiation of the most peripheral location (NI) from the remaining three locations (MR, ER, LHI). Despite high levels of mtDNA gene flow, there is limited msatDNA gene flow with evidence of high levels of self‐replenishment (≥76%) at all four locations. Taken together, this suggests prolonged population recovery times following population declines. The peripheral population (NI) is most vulnerable to local extinction due to its relative isolation, extreme levels of self‐replenishment (95%), and low contemporary abundance. |
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Keywords: |
Chaetodon
coral reefs extinction risk Lord Howe Island marine dispersal Norfolk Island |
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