Open AccessPieces in a global puzzle: Population genetics at two whale shark aggregations in the western Indian Ocean
Author(s) -
Hardenstine Royale S.,
He Song,
Cochran Jesse E. M.,
Braun Camrin D.,
Cagua Edgar Fernando,
Pierce Simon J.,
Prebble Clare E. M.,
Rohner Christoph A.,
SaenzAgudelo Pablo,
SinclairTaylor Tane H.,
Skomal Gregory B.,
Thorrold Simon R.,
Watts Alexandra M.,
Zakroff Casey J.,
Berumen Michael L.
Publication year - 2022
Publication title -
ecology and evolution
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.17
H-Index - 63
ISSN - 2045-7758
DOI - 10.1002/ece3.8492
Subject(s) - whale , biology , mtdna control region , ecology , population , genetic diversity , phylogeography , microsatellite , genetic structure , coral reef fish , fishery , reef , geography , zoology , phylogenetic tree , haplotype , allele , sociology , demography , biochemistry , gene
The whale shark Rhincodon typus is found throughout the world's tropical and warm‐temperate ocean basins. Despite their broad physical distribution, research on the species has been concentrated at a few aggregation sites. Comparing DNA sequences from sharks at different sites can provide a demographically neutral understanding of the whale shark's global ecology. Here, we created genetic profiles for 84 whale sharks from the Saudi Arabian Red Sea and 72 individuals from the coast of Tanzania using a combination of microsatellite and mitochondrial sequences. These two sites, separated by approximately 4500 km (shortest over‐water distance), exhibit markedly different population demographics and behavioral ecologies. Eleven microsatellite DNA markers revealed that the two aggregation sites have similar levels of allelic richness and appear to be derived from the same source population. We sequenced the mitochondrial control region to produce multiple global haplotype networks (based on different alignment methodologies) that were broadly similar to each other in terms of population structure but suggested different demographic histories. Data from both microsatellite and mitochondrial markers demonstrated the stability of genetic diversity within the Saudi Arabian aggregation site throughout the sampling period. These results contrast previously measured declines in diversity at Ningaloo Reef, Western Australia. Mapping the geographic distribution of whale shark lineages provides insight into the species’ connectivity and can be used to direct management efforts at both local and global scales. Similarly, understanding historical fluctuations in whale shark abundance provides a baseline by which to assess current trends. Continued development of new sequencing methods and the incorporation of genomic data could lead to considerable advances in the scientific understanding of whale shark population ecology and corresponding improvements to conservation policy.