For free-swimming marine species like sharks, only population genetics and demographic history analyses can be used to assess population health/status as baseline population numbers are usually unknown. We investigated the population genetics of blacktip reef sharks, Carcharhinus melanopterus; one of the most abundant reef-associated sharks and the apex predator of many shallow water reefs of the Indian and Pacific Oceans. Our sampling includes 4 widely separated locations in the Indo-Pacific and 11 islands in French Polynesia with different levels of coastal development. Four-teen microsatellite loci were analysed for samples from all locations and two mitochondrial DNA fragments, the control region and cytochrome b, were examined for 10 locations. For microsatellites, genetic diversity is higher for the locations in the large open systems of the Red Sea and Australia than for the fragmented habitat of the smaller islands of French Polynesia. Strong significant structure was found for distant locations with FST values as high as ∼0.3, and a smaller but still significant structure is found within French Polynesia. Both mitochondrial genes show only a few mutations across the sequences with a dominant shared haplotype in French Polynesia and New Caledonia suggesting a common lineage different to that of East Australia. Demographic history analyses indicate population expansions in the Red Sea and Australia that may coincide with sea level changes after climatic events. Expansions and flat signals are indicated for French Polynesia as well as a significant recent bottleneck for Moorea, the most human-impacted lagoon of the locations in French Polynesia.
|Original language||English (US)|
|Number of pages||15|
|State||Published - Oct 13 2014|
Bibliographical noteKAUST Repository Item: Exported on 2020-10-01
Acknowledgements: All of the following provided funding for the research presented here (no particular order after the first organization): Labex CORAIL, Ministere de l'Ecologie du Developpement Durable et de l'Energie, Ministere de l'Outre Mer, Fonds Pacifique, IFRECOR, Delegation a la recherche de Polynesie, the Agence Nationale de la Recherche, Institut National de Recherche en Agronomie and a Marie Curie Actions Fellowship. We also thank Andrew Chin, Jennifer Ovenden, Mark Meekan and Conrad Speed, Mael Imirizaldu, David Lecchini, Patrick Plantard, Jonathan Werry and several students for providing samples or for assistance with sampling. Part of the MIGRAINE work was undertaken using the resources of the INRA MIGALE and GENOTOUL bioinformatics platform and the computing grids of ISEM and CBGP laboratories. K. Keenan assisted with the application of diveRsity to our data in R and D. Tracey assisted with developing final figures.
ASJC Scopus subject areas
- Ecology, Evolution, Behavior and Systematics