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Coghlan AR, Morales N. New shark in the park: Tiger shark Galeocerdo cuvier observations in the remote South Pacific. JOURNAL OF FISH BIOLOGY 2024; 104:2098-2101. [PMID: 38556875 DOI: 10.1111/jfb.15737] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2024] [Revised: 03/05/2024] [Accepted: 03/11/2024] [Indexed: 04/02/2024]
Abstract
We present the first photographic records of the tiger shark (Galeocerdo cuvier) at the remote Rapa Nui (Easter Island) in the south-east Pacific. Previous anecdotal sightings exist for tiger sharks in this region; however these records have not been reported within the scientific domain. The present sighting occurred in a period of unusually warm sea surface temperature, which has been shown to influence tiger shark range extensions elsewhere. Novel and historic species occurrence records are valuable for determining and predicting species' environmental tolerances, migratory routes, and distributional limits.
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Affiliation(s)
- Amy Rose Coghlan
- Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, Australia
| | - Naiti Morales
- Millennium Nucleus for Ecology and Sustainable Management of Oceanic Islands (ESMOI). Facultad de Ciencias del Mar, Universidad Católica del Norte, Coquimbo, Chile
- Instituto de Fomento Pesquero (IFOP), Valparaíso, Chile
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2
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Liu Y, Hou L, Liu L, Sulaman A, Muhammad F. Mitochondrial DNA reveals two recent diverged lineages in Amphioctopusaegina (Gray, 1849) (Cephalopoda, Octopodidae) across the Leizhou Peninsula: a marine ecoregion barrier. Zookeys 2023; 1179:299-311. [PMID: 37745623 PMCID: PMC10514695 DOI: 10.3897/zookeys.1179.96015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Accepted: 08/07/2023] [Indexed: 09/26/2023] Open
Abstract
Amphioctopusaegina is an economically important species that has been intensively exploited in the marine areas along the Chinese coast. However, the genetic variation and population genetic structure, which would provide valuable information for their fisheries management, have rarely been investigated. In this study, the genetic variation within and among four A.aegina populations throughout its full distribution range were estimated based on mitochondrial cytochrome b DNA sequences. Our results indicated low (Qinzhou) to high (Dongshan) genetic diversities among the four populations. Analysis of molecular variance (AMOVA), ΦST statistics, phylogenetic tree and haplotype networks revealed two significant (p < 0.01) divergent lineages with a ΦST value of 0.7116 between them, one from a population in Qinzhou and the other from the remaining three populations of Dongshan, Huizhou and Zhanjiang. However, the low genetic distance (0.0032) and only two fixed substitutions between them suggest their recent divergence is possibly due to the last glacial period barriers to gene flow produced by the Leizhou Peninsula. The observed lineage divergence suggests that populations of A.aegina in China are genetically subdivided and may represent evolutionary lineages that should be managed individually.
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Affiliation(s)
- Yantao Liu
- National Engineering Research Centre of Marine Facilities Aquaculture, College of Marine Sciences and Technology, Zhejiang Ocean University, Zhoushan, ChinaZhejiang Ocean UniversityZhoushanChina
| | - Long Hou
- National Engineering Research Centre of Marine Facilities Aquaculture, College of Marine Sciences and Technology, Zhejiang Ocean University, Zhoushan, ChinaZhejiang Ocean UniversityZhoushanChina
| | - Liqin Liu
- National Engineering Research Centre of Marine Facilities Aquaculture, College of Marine Sciences and Technology, Zhejiang Ocean University, Zhoushan, ChinaZhejiang Ocean UniversityZhoushanChina
| | - Amna Sulaman
- Center of Excellence in Marine Biology, University of Karachi, Karachi, PakistanUniversity of KarachiKarachiPakistan
| | - Faiz Muhammad
- Center of Excellence in Marine Biology, University of Karachi, Karachi, PakistanUniversity of KarachiKarachiPakistan
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3
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Lesturgie P, Braun CD, Clua E, Mourier J, Thorrold SR, Vignaud T, Planes S, Mona S. Like a rolling stone: Colonization and migration dynamics of the gray reef shark ( Carcharhinus amblyrhynchos). Ecol Evol 2023; 13:e9746. [PMID: 36644707 PMCID: PMC9831972 DOI: 10.1002/ece3.9746] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2022] [Revised: 12/18/2022] [Accepted: 12/27/2022] [Indexed: 01/13/2023] Open
Abstract
Designing appropriate management plans requires knowledge of both the dispersal ability and what has shaped the current distribution of the species under consideration. Here, we investigated the evolutionary history of the endangered gray reef shark (Carcharhinus amblyrhynchos) across its range by sequencing thousands of RADseq loci in 173 individuals in the Indo-Pacific (IP). We first bring evidence of the occurrence of a range expansion (RE) originating close to the Indo-Australian Archipelago (IAA) where two stepping-stone waves (east and westward) colonized almost the entire IP. Coalescent modeling additionally highlighted a homogenous connectivity (Nm ~ 10 per generation) throughout the range, and isolation by distance model suggested the absence of barriers to dispersal despite the affinity of C. amblyrhynchos to coral reefs. This coincides with long-distance swims previously recorded, suggesting that the strong genetic structure at the IP scale (F ST ~ 0.56 between its ends) is the consequence of its broad current distribution and organization in a large number of demes. Our results strongly suggest that management plans for the gray reef shark should be designed on a range-wide rather than a local scale due to its continuous genetic structure. We further contrasted these results with those obtained previously for the sympatric but strictly lagoon-associated Carcharhinus melanopterus, known for its restricted dispersal ability. Carcharhinus melanopterus exhibits a similar RE dynamic but is characterized by a stronger genetic structure and a nonhomogeneous connectivity largely dependent on local coral reefs availability. This sheds new light on shark evolution, emphasizing the roles of IAA as source of biodiversity and of life-history traits in shaping the extent of genetic structure and diversity.
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Affiliation(s)
- Pierre Lesturgie
- Institut de Systématique, Evolution, Biodiversité (ISYEB), Muséum National d'Histoire Naturelle, EPHE‐PSLUniversité PSL, CNRS, SU, UAParisFrance
| | - Camrin D. Braun
- Biology DepartmentWoods Hole Oceanographic InstitutionWoods HoleMassachusettsUSA
| | - Eric Clua
- Laboratoire d'Excellence CORAILPapetoaiFrench Polynesia
- EPHE, PSL Research UniversityParisFrance
| | - Johann Mourier
- Laboratoire d'Excellence CORAILPapetoaiFrench Polynesia
- Université de Corse Pasquale Paoli, UMS 3514 Plateforme Marine Stella MareBigugliaFrance
| | - Simon R. Thorrold
- Biology DepartmentWoods Hole Oceanographic InstitutionWoods HoleMassachusettsUSA
| | | | - Serge Planes
- Laboratoire d'Excellence CORAILPapetoaiFrench Polynesia
- EPHE, PSL Research UniversityParisFrance
| | - Stefano Mona
- Institut de Systématique, Evolution, Biodiversité (ISYEB), Muséum National d'Histoire Naturelle, EPHE‐PSLUniversité PSL, CNRS, SU, UAParisFrance
- EPHE, PSL Research UniversityParisFrance
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4
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Lesturgie P, Lainé H, Suwalski A, Chifflet-Belle P, Maisano Delser P, Clua E, Jaquemet S, Magalon H, Mona S. Ecological and biogeographic features shaped the complex evolutionary history of an iconic apex predator (Galeocerdo cuvier). BMC Ecol Evol 2022; 22:147. [PMID: 36526977 PMCID: PMC9758794 DOI: 10.1186/s12862-022-02100-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2022] [Accepted: 12/09/2022] [Indexed: 12/23/2022] Open
Abstract
BACKGROUND The tiger shark (Galeocerdo cuvier) is a large iconic marine predator inhabiting worldwide tropical and subtropical waters. So far, only mitochondrial markers and microsatellites studies have investigated its worldwide historical demography with inconclusive outcomes. Here, we assessed for the first time the genomic variability of tiger shark based on RAD-seq data for 50 individuals from five sampling sites in the Indo-Pacific (IP) and one in the Atlantic Ocean (AO) to decipher the extent of the species' global connectivity and its demographic history. RESULTS Clustering algorithms (PCA and NMF), FST and an approximate Bayesian computation framework revealed the presence of two clusters corresponding to the two oceanic basins. By modelling the two-dimensional site frequency spectrum, we tested alternative isolation/migration scenarios between these two identified populations. We found the highest support for a divergence time between the two ocean basins of ~ 193,000 years before present (B.P) and an ongoing but limited asymmetric migration ~ 176 times larger from the IP to the AO (Nm ~ 3.9) than vice versa (Nm ~ 0.02). CONCLUSIONS The two oceanic regions are isolated by a strong barrier to dispersal more permeable from the IP to the AO through the Agulhas leakage. We finally emphasized contrasting recent demographic histories for the two regions, with the IP characterized by a recent bottleneck around 2000 years B.P. and the AO by an expansion starting 6000 years B.P. The large differentiation between the two oceanic regions and the absence of population structure within each ocean basin highlight the need for two large management units and call for future conservation programs at the oceanic rather than local scale, particularly in the Indo-Pacific where the population is declining.
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Affiliation(s)
- Pierre Lesturgie
- grid.503191.f0000 0001 0143 5055Institut de Systématique, Evolution, Biodiversité (ISYEB), EPHE-PSL, Université PSL, MNHN, CNRS, SU, UA, Paris, France
| | - Hugo Lainé
- grid.503191.f0000 0001 0143 5055Institut de Systématique, Evolution, Biodiversité (ISYEB), EPHE-PSL, Université PSL, MNHN, CNRS, SU, UA, Paris, France
| | - Arnaud Suwalski
- grid.503191.f0000 0001 0143 5055Institut de Systématique, Evolution, Biodiversité (ISYEB), EPHE-PSL, Université PSL, MNHN, CNRS, SU, UA, Paris, France ,grid.424469.90000 0001 2195 5365EPHE, PSL Research University, Paris, France
| | - Pascaline Chifflet-Belle
- grid.503191.f0000 0001 0143 5055Institut de Systématique, Evolution, Biodiversité (ISYEB), EPHE-PSL, Université PSL, MNHN, CNRS, SU, UA, Paris, France ,grid.424469.90000 0001 2195 5365EPHE, PSL Research University, Paris, France
| | | | - Eric Clua
- grid.424469.90000 0001 2195 5365EPHE, PSL Research University, Paris, France ,Laboratoire d’Excellence CORAIL, Papetoai, French Polynesia
| | - Sébastien Jaquemet
- grid.11642.300000 0001 2111 2608UMR ENTROPIE (Université de La Réunion/IRD/CNRS), Université de La Réunion, Saint Denis, France
| | - Hélène Magalon
- Laboratoire d’Excellence CORAIL, Papetoai, French Polynesia ,grid.11642.300000 0001 2111 2608UMR ENTROPIE (Université de La Réunion/IRD/CNRS), Université de La Réunion, Saint Denis, France
| | - Stefano Mona
- grid.503191.f0000 0001 0143 5055Institut de Systématique, Evolution, Biodiversité (ISYEB), EPHE-PSL, Université PSL, MNHN, CNRS, SU, UA, Paris, France ,grid.424469.90000 0001 2195 5365EPHE, PSL Research University, Paris, France ,Laboratoire d’Excellence CORAIL, Papetoai, French Polynesia
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5
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Population structure and genetic connectivity of the scalloped hammerhead shark (Sphyrna lewini) across nursery grounds from the Eastern Tropical Pacific: Implications for management and conservation. PLoS One 2022; 17:e0264879. [PMID: 36525407 PMCID: PMC9757582 DOI: 10.1371/journal.pone.0264879] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2022] [Accepted: 08/18/2022] [Indexed: 12/23/2022] Open
Abstract
Defining demographically independent units and understanding patterns of gene flow between them is essential for managing and conserving exploited populations. The critically endangered scalloped hammerhead shark, Sphyrna lewini, is a coastal semi-oceanic species found worldwide in tropical and subtropical waters. Pregnant females give birth in shallow coastal estuarine habitats that serve as nursery grounds for neonates and small juveniles, whereas adults move offshore and become highly migratory. We evaluated the population structure and connectivity of S. lewini in coastal areas and one oceanic island (Cocos Island) across the Eastern Tropical Pacific (ETP) using both sequences of the mitochondrial DNA control region (mtCR) and 9 nuclear-encoded microsatellite loci. The mtCR defined two genetically discrete groups: one in the Mexican Pacific and another one in the central-southern Eastern Tropical Pacific (Guatemala, Costa Rica, Panama, and Colombia). Overall, the mtCR data showed low levels of haplotype diversity ranging from 0.000 to 0.608, while nucleotide diversity ranged from 0.000 to 0.0015. More fine-grade population structure was detected using microsatellite loci where Guatemala, Costa Rica, and Panama differed significantly. Relatedness analysis revealed that individuals within nursery areas were more closely related than expected by chance, suggesting that S. lewini may exhibit reproductive philopatric behaviour within the ETP. Findings of at least two different management units, and evidence of philopatric behaviour call for intensive conservation actions for this highly threatened species in the ETP.
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6
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Smukall MJ, Carlson J, Kessel ST, Guttridge TL, Dhellemmes F, Seitz AC, Gruber S. Thirty-five years of tiger shark Galeocerdo cuvier relative abundance near Bimini, The Bahamas, and the Southeastern United States with a comparison across jurisdictional bounds. JOURNAL OF FISH BIOLOGY 2022; 101:13-25. [PMID: 35446438 DOI: 10.1111/jfb.15067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/08/2021] [Revised: 10/17/2021] [Accepted: 04/13/2022] [Indexed: 06/14/2023]
Abstract
Abundances of large sharks are reported to have declined worldwide, and in response various levels of fisheries management and conservation efforts have been established. For example, marine-protected areas have been suggested as a means to protect large expanses of ocean from fishing and other industrial activities (e.g., habitat destruction), and in 2011 The Commonwealth of The Bahamas established The Bahamas Shark Sanctuary. Nonetheless, assessing the effectiveness of conservation efforts is challenging because consistent long-term data sets of shark abundances are often lacking, especially throughout the Caribbean and The Bahamas. In this study, the authors investigated the catch rates and demographics of tiger sharks Galeocerdo cuvier caught in a fishery-independent survey near Bimini, The Bahamas, from 1984 to 2019 to assess relative abundance trends following the banning of longline fishing in 1993 and the subsequent establishment of the shark sanctuary. To contextualize the relative abundance trends near Bimini, the authors compared this to the relative abundance of tiger sharks in a fishery-dependent survey from the Southeastern USA (SE USA), conducted from 1994 to 2019. The data of this study suggest that local abundance of tiger sharks has been stable near Bimini since the 1980s, including after the ban of longline fishing and the implementation of the shark sanctuary. In comparison, the abundance near the SE USA has slowly increased in the past decade, following potential declines in the decade preceding the USA Shark Management Plan. The results of this study provide some optimism that current conservation efforts in The Bahamas have been effective to maintain local tiger shark abundance within the protected area. In addition, current fisheries management in the SE USA is allowing this species to recover within those waters.
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Affiliation(s)
- Matthew J Smukall
- Bimini Biological Field Station Foundation, Bimini, The Bahamas
- University of Alaska Fairbanks, College of Fisheries and Ocean Sciences, Fairbanks, Alaska, USA
| | - John Carlson
- National Oceanic and Atmospheric Administration, Panama City, Florida, USA
| | - Steven T Kessel
- Bimini Biological Field Station Foundation, Bimini, The Bahamas
- Shedd Aquarium, Chicago, Illinois, USA
| | - Tristan L Guttridge
- Bimini Biological Field Station Foundation, Bimini, The Bahamas
- Saving the Blue, Cooper City, Florida, USA
| | - Félicie Dhellemmes
- Bimini Biological Field Station Foundation, Bimini, The Bahamas
- Leibniz-Institute of Freshwater Ecology and Inland Fisheries, Berlin, Germany
| | - Andrew C Seitz
- University of Alaska Fairbanks, College of Fisheries and Ocean Sciences, Fairbanks, Alaska, USA
| | - Samuel Gruber
- Bimini Biological Field Station Foundation, Bimini, The Bahamas
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7
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Manuzzi A, Jiménez-Mena B, Henriques R, Holmes BJ, Pepperell J, Edson J, Bennett MB, Huveneers C, Ovenden JR, Nielsen EE. Retrospective genomics highlights changes in genetic composition of tiger sharks (Galeocerdo cuvier) and potential loss of a south-eastern Australia population. Sci Rep 2022; 12:6582. [PMID: 35449439 PMCID: PMC9023511 DOI: 10.1038/s41598-022-10529-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Accepted: 04/06/2022] [Indexed: 11/08/2022] Open
Abstract
Over the last century, many shark populations have declined, primarily due to overexploitation in commercial, artisanal and recreational fisheries. In addition, in some locations the use of shark control programs also has had an impact on shark numbers. Still, there is a general perception that populations of large ocean predators cover wide areas and therefore their diversity is less susceptible to local anthropogenic disturbance. Here we report on temporal genomic analyses of tiger shark (Galeocerdo cuvier) DNA samples that were collected from eastern Australia over the past century. Using Single Nucleotide Polymorphism (SNP) loci, we documented a significant change in genetic composition of tiger sharks born between ~1939 and 2015. The change was most likely due to a shift over time in the relative contribution of two well-differentiated, but hitherto cryptic populations. Our data strongly indicate a dramatic shift in the relative contribution of these two populations to the overall tiger shark abundance on the east coast of Australia, possibly associated with differences in direct or indirect exploitation rates.
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Affiliation(s)
- Alice Manuzzi
- National Institute of Aquatic Resources, Technical University of Denmark, Vejlsøvej 39, 8600, Silkeborg, Denmark.
| | - Belen Jiménez-Mena
- National Institute of Aquatic Resources, Technical University of Denmark, Vejlsøvej 39, 8600, Silkeborg, Denmark
| | - Romina Henriques
- National Institute of Aquatic Resources, Technical University of Denmark, Vejlsøvej 39, 8600, Silkeborg, Denmark
| | - Bonnie J Holmes
- School of Science, Technology & Engineering, University of the Sunshine Coast, Sippy Downs, QLD, 4556, Australia
| | - Julian Pepperell
- Pepperell Research and Consulting, PO Box 1475, Noosaville DC, QLD, 4566, Australia
| | - Janette Edson
- Queensland Brain Institute, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Mike B Bennett
- School of Biomedical Sciences, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Charlie Huveneers
- College of Science and Engineering, Flinders University, Adelaide, SA, 5001, Australia
| | - Jennifer R Ovenden
- Molecular Fisheries Laboratory, School of Biomedical Sciences, The University of Queensland, Brisbane, QLD, 4072, Australia
| | - Einar E Nielsen
- National Institute of Aquatic Resources, Technical University of Denmark, Vejlsøvej 39, 8600, Silkeborg, Denmark
- School of Biomedical Sciences, The University of Queensland, Brisbane, QLD, 4072, Australia
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8
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Lesturgie P, Planes S, Mona S. Coalescence times, life history traits and conservation concerns: An example from four coastal shark species from the Indo-Pacific. Mol Ecol Resour 2021; 22:554-566. [PMID: 34407294 DOI: 10.1111/1755-0998.13487] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2021] [Revised: 07/27/2021] [Accepted: 08/12/2021] [Indexed: 11/30/2022]
Abstract
Dispersal abilities play a crucial role in shaping the extent of population genetic structure, with more mobile species being panmictic over large geographical ranges and less mobile ones organized in metapopulations exchanging migrants to different degrees. In turn, population structure directly influences the coalescence pattern of the sampled lineages, but the consequences on the estimated variation of the effective population size (Ne ) over time obtained by means of unstructured demographic models remain poorly understood. However, this knowledge is crucial for biologically interpreting the observed Ne trajectory and further devising conservation strategies in endangered species. Here we investigated the demographic history of four shark species (Carharhinus melanopterus, Carharhinus limbatus, Carharhinus amblyrhynchos, Galeocerdo cuvier) with different degrees of endangered status and life history traits related to dispersal distributed in the Indo-Pacific and sampled off New Caledonia. We compared several evolutionary scenarios representing both structured (metapopulation) and unstructured models and then inferred the Ne variation through time. By performing extensive coalescent simulations, we provided a general framework relating the underlying population structure and the observed Ne dynamics. On this basis, we concluded that the recent decline observed in three out of the four considered species when assuming unstructured demographic models can be explained by the presence of population structure. Furthermore, we also demonstrated the limits of the inferences based on the sole site frequency spectrum and warn that statistics based on linkage disequilibrium will be needed to exclude recent demographic events affecting meta-populations.
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Affiliation(s)
- Pierre Lesturgie
- Institut de Systématique, Evolution, Biodiversité, ISYEB (UMR 7205), Muséum National d'Histoire Naturelle, CNRS, Sorbonne Université, EPHE, Université des Antilles, Paris, France
| | - Serge Planes
- PSL Research University: EPHE-UPVD-CNRS, USR 3278 CRIOBE, Université de Perpignan, Perpignan, France.,Laboratoire d'Excellence CORAIL, Papetoai, French Polynesia
| | - Stefano Mona
- Institut de Systématique, Evolution, Biodiversité, ISYEB (UMR 7205), Muséum National d'Histoire Naturelle, CNRS, Sorbonne Université, EPHE, Université des Antilles, Paris, France.,Laboratoire d'Excellence CORAIL, Papetoai, French Polynesia.,EPHE, PSL Research University, Paris, France
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9
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Bernard AM, Finnegan KA, Pavinski Bitar P, Stanhope MJ, Shivji MS. Genomic assessment of global population structure in a highly migratory and habitat versatile apex predator, the tiger shark (Galeocerdo cuvier). J Hered 2021; 112:497-507. [PMID: 34374783 DOI: 10.1093/jhered/esab046] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Accepted: 08/09/2021] [Indexed: 11/12/2022] Open
Abstract
Understanding the population dynamics of highly mobile, widely distributed, oceanic sharks, many of which are overexploited, is necessary to aid their conservation management. We investigated the global population genomics of tiger sharks (Galeocerdo cuvier), a circumglobally distributed, apex predator displaying remarkable behavioral versatility in its diet, habitat use (near coastal, coral reef, pelagic), and individual movement patterns (spatially resident to long-distance migrations). We genotyped 242 tiger sharks from 10 globally distributed locations at more than 2000 single nucleotide polymorphisms. Although this species often conducts massive distance migrations, the data show strong genetic differentiation at both neutral (FST=0.125-0.144) and candidate outlier loci (FST=0.570-0.761) between western Atlantic and Indo-Pacific sharks, suggesting the potential for adaptation to the environments specific to these oceanic regions. Within these regions, there was mixed support for population differentiation between northern and southern hemispheres in the western Atlantic, and none for structure within the Indian Ocean. Notably, the results demonstrate a low level of population differentiation of tiger sharks from the remote Hawaiian archipelago compared to sharks from the Indian Ocean (FST=0.003-0.005, P<0.01). Given concerns about biodiversity loss and marine ecosystem impacts caused by overfishing of oceanic sharks in the midst of rapid environmental change, our results suggest it imperative that international fishery management prioritize conservation of the evolutionary potential of the highly genetically differentiated Atlantic and Indo-Pacific populations of this unique apex predator. Furthermore, we suggest targeted management attention to tiger sharks in the Hawaiian archipelago based on a precautionary biodiversity conservation perspective.
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Affiliation(s)
- Andrea M Bernard
- Save Our Seas Foundation Shark Research Center, Nova Southeastern University, 8000 North Ocean Drive, Dania Beach, Florida, USA
| | - Kimberly A Finnegan
- Save Our Seas Foundation Shark Research Center, Nova Southeastern University, 8000 North Ocean Drive, Dania Beach, Florida, USA.,Guy Harvey Research Institute, Nova Southeastern University, 8000 North Ocean Drive, Dania Beach, Florida, USA
| | - Paulina Pavinski Bitar
- Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, USA
| | - Michael J Stanhope
- Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY, USA
| | - Mahmood S Shivji
- Save Our Seas Foundation Shark Research Center, Nova Southeastern University, 8000 North Ocean Drive, Dania Beach, Florida, USA.,Guy Harvey Research Institute, Nova Southeastern University, 8000 North Ocean Drive, Dania Beach, Florida, USA
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10
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11
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Forensic genetic identification of sharks involved in human attacks. Forensic Sci Int Genet 2021; 54:102558. [PMID: 34217058 DOI: 10.1016/j.fsigen.2021.102558] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Revised: 06/22/2021] [Accepted: 06/23/2021] [Indexed: 11/22/2022]
Abstract
Each year, 75-100 unprovoked shark attacks on humans are recorded, most of them resulting in no or minor injuries, while a few are fatal. Often, shark identification responsible for attacks relies on visual observations or bite wound characteristics, which limits species determination and preclude individual identification. Here, we provide two genetic approaches to reliably identify species and/or individuals involved in shark attacks on humans based on a non-invasive DNA sampling (i.e. DNA traces present on bite wounds on victims), depending on the knowledge of previous attack history at the site. The first approach uses barcoding techniques allowing species identification without any a priori, while the second relies on microsatellite genotyping, allowing species identification confirmation and individual identification, but requiring an a priori of the potential species involved in the attack. Both approaches were validated by investigating two shark attacks that occurred in Reunion Island (southwestern Indian Ocean). According to both methods, each incident was attributed to a bull shark (Carcharhinus leucas), in agreement with suggestions derived from bite wound characteristics. Both approaches appear thus suitable for the reliable identification of species involved in shark attacks on humans. Moreover, microsatellite genotyping reveals, in the studied cases, that two distinct individuals were responsible of the bites. Applying these genetic identification methods will resolve ambiguities on shark species involved in attacks and allow the collection of individual data to better understand and mitigate shark risk.
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12
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Sort M, Manuzzi A, Jiménez-Mena B, Ovenden JR, Holmes BJ, Bernard AM, Shivji MS, Meldrup D, Bennett MB, Nielsen EE. Come together: calibration of tiger shark (Galeocerdo cuvier) microsatellite databases for investigating global population structure and assignment of historical specimens. CONSERV GENET RESOUR 2021. [DOI: 10.1007/s12686-021-01197-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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13
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Chynel M, Munschy C, Bely N, Héas-Moisan K, Pollono C, Jaquemet S. Legacy and emerging organic contaminants in two sympatric shark species from Reunion Island (Southwest Indian Ocean): Levels, profiles and maternal transfer. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 751:141807. [PMID: 33181997 DOI: 10.1016/j.scitotenv.2020.141807] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Revised: 08/09/2020] [Accepted: 08/17/2020] [Indexed: 06/11/2023]
Abstract
The contamination of tiger sharks (Galeocerdo cuvier) and bull sharks (Carcharhinus leucas) by legacy persistent organic pollutants (POPs) and emerging organic contaminants was investigated in specimens from Reunion Island (Southwest Indian Ocean) in 2018 and 2019. Contamination levels were determined in the muscle of adult individuals of both sexes in relation to biological and trophic parameters. Maternal transfer was additionally investigated in one set of embryos in each species. Polychlorinated biphenyl (PCB), organochlorinated pesticide (OCP) and perfluoroalkylated substance (PFAS) concentrations were 2597 ± 2969, 785 ± 966 and 267 ± 194 pg g-1 ww, respectively, in bull sharks, and 339 ± 270, 1025 ± 946 and 144 ± 53 pg g-1 ww in tiger sharks. The results highlighted higher PCB contamination, and by the heavier congeners, in adult bull sharks versus tiger sharks. The significant differences found in PCB profiles and concentrations suggest that the two species are exposed to different contamination sources. As bull sharks rely on a more coastal habitat for feeding, their higher contamination by PCBs suggests the occurrence of local PCB sources. DDT concentrations were similar in both species, suggesting a more homogeneous contamination on the scale of the Southwest Indian Ocean. Female bull sharks showed lower OCP and PCB concentrations than males, while this trend was not observed in tiger sharks. The ratio of chlorinated contaminants in muscle between the mother and her embryos was related to molecule hydrophobicity in bull shark but not in tiger shark, suggesting that shark mode of gestation, known to be different in the two species, is a key driver of organic contaminant maternal transfer. Finally, the results show that organic contaminant levels in the studied species were lower than those of other shark species in the Southern Hemisphere, related to the limited urbanization and industrialization of Reunion Island.
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Affiliation(s)
- M Chynel
- IFREMER (French Research Institute for Exploitation of the Sea), Laboratory of Biogeochemistry of Organic Contaminants, Rue de l'Ile d'Yeu, BP 21105, 44311 Nantes Cedex 3, France
| | - C Munschy
- IFREMER (French Research Institute for Exploitation of the Sea), Laboratory of Biogeochemistry of Organic Contaminants, Rue de l'Ile d'Yeu, BP 21105, 44311 Nantes Cedex 3, France.
| | - N Bely
- IFREMER (French Research Institute for Exploitation of the Sea), Laboratory of Biogeochemistry of Organic Contaminants, Rue de l'Ile d'Yeu, BP 21105, 44311 Nantes Cedex 3, France
| | - K Héas-Moisan
- IFREMER (French Research Institute for Exploitation of the Sea), Laboratory of Biogeochemistry of Organic Contaminants, Rue de l'Ile d'Yeu, BP 21105, 44311 Nantes Cedex 3, France
| | - C Pollono
- IFREMER (French Research Institute for Exploitation of the Sea), Laboratory of Biogeochemistry of Organic Contaminants, Rue de l'Ile d'Yeu, BP 21105, 44311 Nantes Cedex 3, France
| | - S Jaquemet
- Université de La Réunion, UMR 9220 ENTROPIE (Université de La Réunion-CNRS-IRD), Avenue René Cassin CS 92003, 97744 Saint-Denis Cedex 9, Ile de La Réunion, France
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Pirog A, Magalon H, Poirout T, Jaquemet S. Reproductive biology, multiple paternity and polyandry of the bull shark Carcharhinus leucas. JOURNAL OF FISH BIOLOGY 2019; 95:1195-1206. [PMID: 31393599 DOI: 10.1111/jfb.14118] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Accepted: 08/06/2019] [Indexed: 05/05/2023]
Abstract
To improve understanding of bull shark Carcharhinus leucas reproductive biology, we analysed reproductive traits from 118 bull sharks caught along Reunion Island coasts (Western Indian Ocean), including 16 gravid females. Specific microsatellite loci were used to investigate the frequency of multiple paternity. Males and females reached maturity at c. 234 cm and 257 cm total length (LT ), respectively, and litter sizes ranged from 5 to 14 embryos. Analysis of the 16 litters collected in various months of the year indicated that parturition occurs between October and December, with a size at birth c. 60-80 cm LT and that the gestation period is probably c. 12 months. Assuming a 1 year resting period and a period of sperm storage (4-5 months) between mating (in June-September) and fertilisation, the reproductive cycle of bull sharks at Reunion Island would be biennial. At least 56.25% of the litters investigated were polyandrous, sired by 2-5 males. Several males that each sired several litters conceived during the same or distinct mating seasons were detected, suggesting both a seasonal aggregation of sharks to mate and some male fidelity to mating site. Altogether, these findings provide valuable information for both shark risk management and conservation of the species in the Western Indian Ocean.
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Affiliation(s)
- Agathe Pirog
- UMR ENTROPIE (Université de La Réunion/IRD/CNRS), Université de La Réunion, Saint Denis, France
| | - Hélène Magalon
- UMR ENTROPIE (Université de La Réunion/IRD/CNRS), Université de La Réunion, Saint Denis, France
- Laboratoire d'Excellence CORAIL, Perpignan, France
| | - Thomas Poirout
- UMR ENTROPIE (Université de La Réunion/IRD/CNRS), Université de La Réunion, Saint Denis, France
| | - Sébastien Jaquemet
- UMR ENTROPIE (Université de La Réunion/IRD/CNRS), Université de La Réunion, Saint Denis, France
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15
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Pirog A, Jaquemet S, Ravigné V, Cliff G, Clua E, Holmes BJ, Hussey NE, Nevill JEG, Temple AJ, Berggren P, Vigliola L, Magalon H. Genetic population structure and demography of an apex predator, the tiger shark Galeocerdo cuvier. Ecol Evol 2019; 9:5551-5571. [PMID: 31160982 PMCID: PMC6540675 DOI: 10.1002/ece3.5111] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Revised: 01/20/2019] [Accepted: 02/26/2019] [Indexed: 12/16/2022] Open
Abstract
Population genetics has been increasingly applied to study large sharks over the last decade. Whilst large shark species are often difficult to study with direct methods, improved knowledge is needed for both population management and conservation, especially for species vulnerable to anthropogenic and climatic impacts. The tiger shark, Galeocerdo cuvier, is an apex predator known to play important direct and indirect roles in tropical and subtropical marine ecosystems. While the global and Indo-West Pacific population genetic structure of this species has recently been investigated, questions remain over population structure and demographic history within the western Indian (WIO) and within the western Pacific Oceans (WPO). To address the knowledge gap in tiger shark regional population structures, the genetic diversity of 286 individuals sampled in seven localities was investigated using 27 microsatellite loci and three mitochondrial genes (CR,COI, and cytb). A weak genetic differentiation was observed between the WIO and the WPO, suggesting high genetic connectivity. This result agrees with previous studies and highlights the importance of the pelagic behavior of this species to ensure gene flow. Using approximate Bayesian computation to couple information from both nuclear and mitochondrial markers, evidence of a recent bottleneck in the Holocene (2,000-3,000 years ago) was found, which is the most probable cause for the low genetic diversity observed. A contemporary effective population size as low as 111 [43,369] was estimated during the bottleneck. Together, these results indicate low genetic diversity that may reflect a vulnerable population sensitive to regional pressures. Conservation measures are thus needed to protect a species that is classified as Near Threatened.
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Affiliation(s)
- Agathe Pirog
- UMR ENTROPIE (Université de La Réunion/IRD/CNRS)Université de La RéunionSaint Denis, La RéunionFrance
| | - Sébastien Jaquemet
- UMR ENTROPIE (Université de La Réunion/IRD/CNRS)Université de La RéunionSaint Denis, La RéunionFrance
| | | | - Geremy Cliff
- KwaZulu‐Natal Sharks BoardUmhlanga RocksSouth Africa
- School of Life SciencesUniversity of KwaZulu‐NatalDurbanSouth Africa
| | - Eric Clua
- EPHE‐CNRS‐UPVDCNRS UPVDUSR 3278 CRIOBEPSL Research UniversityPerpignanFrance
- Laboratoire d'Excellence CORAILPerpignanFrance
| | - Bonnie J. Holmes
- School of Biological SciencesUniversity of Queensland, St LuciaBrisbaneQueenslandAustralia
| | - Nigel E. Hussey
- Biological SciencesUniversity of WindsorWindsorOntarioCanada
| | | | - Andrew J. Temple
- School of Natural and Environmental SciencesNewcastle UniversityNewcastle‐upon‐TyneUK
| | - Per Berggren
- School of Natural and Environmental SciencesNewcastle UniversityNewcastle‐upon‐TyneUK
| | - Laurent Vigliola
- Laboratoire d'Excellence CORAILPerpignanFrance
- UMR ENTROPIE (Université de La Réunion/IRD/CNRS)Institut de Recherche pour le DéveloppementNouméaNouvelle CalédonieFrance
| | - Hélène Magalon
- UMR ENTROPIE (Université de La Réunion/IRD/CNRS)Université de La RéunionSaint Denis, La RéunionFrance
- Laboratoire d'Excellence CORAILPerpignanFrance
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