Conservation Genetics

, Volume 12, Issue 2, pp 371–382

Phylogeography and conservation of the bull shark (Carcharhinus leucas) inferred from mitochondrial and microsatellite DNA

  • S. A. Karl
  • A. L. F. Castro
  • J. A. Lopez
  • P. Charvet
  • G. H. Burgess
Research Article

DOI: 10.1007/s10592-010-0145-1

Cite this article as:
Karl, S.A., Castro, A.L.F., Lopez, J.A. et al. Conserv Genet (2011) 12: 371. doi:10.1007/s10592-010-0145-1

Abstract

The bull shark (Carcharhinus leucas) is a widely distributed, large coastal shark species known to travel long distances. These characteristics, coupled with the species’ long life span and late age of maturity, would lead one to predict significant global genetic exchange among bull shark populations. By contrast, data show localized depletion in some areas of large coastal shark fisheries, indicating some geographic isolation may exist. We examined genetic variation in the control region of mitochondrial DNA and at five nuclear microsatellite loci in bull sharks sampled from the western Atlantic to investigate the degree of population subdivision. The average per sample haplotype and nucleotide diversity in the mtDNA (0.51 ± 0.26 and 0.12% ± 0.12, respectively) and expected heterozygosity (0.84) in the microsatellite loci contrast sharply in having lower and higher values (respectively) relative to many other shark species. Significant structure exists between the Brazilian and all northern populations at the mtDNA control region (pairwise ΦST > 0.8, P < 0.001), but not at the nuclear microsatellite loci. Adjacent northern populations show weak to no genetic differentiation for both markers. These results are congruent with restricted maternal gene flow between populations caused by female site fidelity to nursery areas. We estimate the current effective population size to be around 160,000 and 221,000 individuals for the southern and northern Atlantic populations, respectively. The philopatric habits and the relatively low levels of mtDNA genetic diversity observed in bull sharks must be considered in the conservation of this species. Our results indicate that effective bull shark management strategies will require local, regional, and international attention and cooperation.

Keywords

mtDNA control regionMicrosatellitePopulation structurePhilopatry

Supplementary material

10592_2010_145_MOESM1_ESM.doc (274 kb)
Supplementary material 1 (DOC 274 kb)

Copyright information

© Springer Science+Business Media B.V. 2010

Authors and Affiliations

  • S. A. Karl
    • 1
  • A. L. F. Castro
    • 2
    • 3
  • J. A. Lopez
    • 4
  • P. Charvet
    • 5
  • G. H. Burgess
    • 6
  1. 1.The Hawai`i Institute of Marine BiologyUniversity of Hawai`i, MānoaKāne`oheUSA
  2. 2.Department of BiologyUniversity of South FloridaTampaUSA
  3. 3.Departamento de Engenharia de BiossistemasUniversidade Federal de São João del ReiSão João Del ReiBrazil
  4. 4.University of Alaska MuseumFairbanksUSA
  5. 5.SENAI-PR, Rua Senador Accioly FilhoCuritibaBrazil
  6. 6.Florida Program for Shark Research, Florida Museum of Natural HistoryUniversity of FloridaGainesvilleUSA