Putative long distance gene flow and evidence of secondary outbreaks of the Crown-of-Thorns Starfish in the Pacific Ocean
- Published
- Accepted
- Subject Areas
- Biogeography, Evolutionary Studies, Marine Biology
- Keywords
- Acanthaster ‘planci’, crown-of-thorns starfish, microsatellites, outbreak, larval migration, Pacific
- Copyright
- © 2015 Tusso et al.
- Licence
- This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, reproduction and adaptation in any medium and for any purpose provided that it is properly attributed. For attribution, the original author(s), title, publication source (PeerJ PrePrints) and either DOI or URL of the article must be cited.
- Cite this article
- 2015. Putative long distance gene flow and evidence of secondary outbreaks of the Crown-of-Thorns Starfish in the Pacific Ocean. PeerJ PrePrints 3:e1167v1 https://doi.org/10.7287/peerj.preprints.1167v1
Abstract
Population outbreaks of the corallivorous crown-of-thorns starfish (COTS), Acanthaster ‘planci’ L., are considered among the most important biological disturbances of tropical coral reefs. A local COTS outbreak, a “primary outbreak”, can lead to so-called “secondary outbreaks” in adjacent coral reefs due to increased larval release and subsequent dispersion. Previous analyses have shown that in the Pacific Ocean, this dispersion may be geographically restricted to certain regions. Guam, an island in the western Pacific region, suffered from several COTS outbreaks in the last 50 years, and in this study we test whether Guam is genetically connected with surrounding regions as a consequence of secondary outbreaks. We used microsatellites to measure gene flow and genetic structure among 14 localities in the Pacific Ocean. Our results show substantial genetic structure between geographical regions. There was, however, a lack of significant genetic differentiation between localities separated by large geographic distances (e.g., Guam, Kingman Reef and Johnston Atoll) – a finding consistent with the existence of contemporary long distance larval dispersion and the gradual erasing of ancestral signatures of divergence. Long distance larval dispersion suggests that secondary outbreaks occur across regions in the Pacific, and have occurred in the recent outbreaks in Guam. However, significant genetic differences among outbreak localities around the island of Guam were also detected, revealing the signature of both primary and secondary outbreaks. Our findings highlight the importance of addressing likely triggers of both primary and secondary outbreaks in conservation efforts and programs that strive to control the growth and spread of A. ‘planci’ in the Pacific Ocean.
Author Comment
This is a submission to PeerJ for review.
Supplemental Information
Raw Data
Raw genotype data per locus and individual. Each line corresponds to one individual. The values are given in length (bp) of the fragment. Empty spaces are missing data.