Title

Genetic Connectivity of a Coral Reef Ecosystem Predator: The Population Genetic Structure and Evolutionary History of the Caribbean Reef Shark (Carcharhinus perezi)

Document Type

Article

Publication Date

7-26-2017

Publication Title

Journal of Biogeography

Keywords

Coral reefs, Elasmobranch, Evolutionary history, Marine biogeography, Microsatellite DNA, Mitochondrial DNA, Population structure, Western Atlantic

ISSN

0305-0270

First Page

1

Last Page

13

Abstract

Aim

The Caribbean reef shark (Carcharhinus perezi) is one of few extant reef sharks inhabiting the Atlantic Ocean. Its variability in movements across habitat types suggests the possibility of a complex genetic population structure. Here, we use mitochondrial and nuclear DNA to investigate the genetic connectivity of the Caribbean reef shark across contemporary and evolutionary time-scales and relate our findings to the ecology of this understudied species.

Location

Tropical western Atlantic and Caribbean.

Methods

Samples were obtained from 216 individuals from six western Atlantic and Caribbean locations. Individuals were genotyped at seven nuclear microsatellite DNA loci and sequenced at two mitochondrial (control region [CR]; NADH dehydrogenase subunit 4 [ND4]) and one nuclear locus (lactate dehydrogenase [LDH]). Analyses to resolve the population genetic structure and evolutionary history of this species were adopted.

Results

Sequencing of the CR (1,068 bp, n = 216), ND4 (741 bp, n = 213) and LDH (258 bp, n = 165) loci, resolved 11, 8 and 13 unique haplotypes (or alleles), respectively. Overall, Caribbean reef sharks showed low levels of genetic diversity and most marker sets identified strong genetic differences (FSTand ΦST) between sharks sampled in Brazil versus all other locations (msat FST > 0.017; CR-ND4 ΦST > 0.013). Mitochondrial DNA showed evidence of increased genetic partitioning among western North Atlantic sampling sites, although widespread haplotype sharing (~85%–92%) and a shallow population history were found.

Main Conclusions

Findings of genetic differentiation are concordant with previous movement studies showing residency and/or site-fidelity to specific locations by individuals. However, similar to other reef shark studies, we found that the level of genetic connectivity among populations was context dependent—i.e., sharks occupying isolated habitats showed greater genetic differentiation compared with those sharks occupying semi-isolated or continuous reef habitats. Furthermore, low genetic diversity and a shallow mitochondrial population history were found, suggesting historical demographic fluctuations, including population collapse and more recent expansions.

Comments

©2017 John Wiley & Sons Ltd

Additional Comments

Sao Paulo Research Foundation grant #: FAPESP #1998/15080-8

ResearcherID

G-4080-2013

DOI

10.1111/jbi.13062

This document is currently not available here.

Peer Reviewed

Find in your library

Share

COinS