Putative long distance gene flow 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 of the Crown-of-Thorns Starfish in the Pacific Ocean. PeerJ PrePrints 3:e1167v2 https://doi.org/10.7287/peerj.preprints.1167v2
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 severe COTS outbreaks in the last 50 years, and in this study we tested whether Guam is genetically connected with surrounding long distant regions. 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. Our findings highlight the importance of addressing likely triggers of both primary and secondary outbreaks in conservation efforts using highly variable markers that provide enough variance to infer contemporary patterns of gene-flow and allow to implement programs that strive to control the growth and spread of A. ‘planci’ in the Pacific Ocean.
Author Comment
This is a revised version after peer review.
Supplemental Information
Predicted allelic richness in function of sample size
Predicted allelic richness in function of sample size. Each line represents sampled localities. Localities with the lowest and highest allelic richness are shown in red and blue respectively, with their variance in dash lines.
Results of the discriminant analysis of principal components (DAPC)
Results of the discriminant analysis of principal components (DAPC). Values of the Bayesian Information Criteria (BIC) in function of number of clusters.
Genetic diversity estimates for 10 microsatellite loci all the localities
Genetic diversity estimates for 10 microsatellite loci all the localities. N number of individuals, Na number of allele per locus, Ar allelic richness, Ho observed heterozygosity, He expected heterozygosity, FIS inbreeding coefficient.
Pairwise Fst bootstrap
Pairwise Fst bootstrap. CI: confidence intervals. BC: Bonferroni correction.