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Predominance of Genetic Monogamy by Females in a Hammerhead Shark, Sphyrna tiburo: Implications for Shark Conservation
Molecular Ecology
  • Demian D. Chapman, Nova Southeastern University
  • Paulo A. Prodohl, Queen's University - Belfast, United Kingdom
  • James Gelsleichter, Mote Marine Laboratory
  • Charles A. Manire, Mote Marine Laboratory
  • Mahmood S. Shivji, Nova Southeastern University
Document Type
Publication Date
  • Bonnethead shark,
  • Conservation,
  • Genetic monogamy,
  • Mating system,
  • Microsatellite DNA profiling,
  • Multiple paternity,
  • Sphyrna tiburo
There is growing interest in the mating systems of sharks and their relatives (Class Chondrichthyes) because these ancient fishes occupy a key position in vertebrate phylogeny and are increasingly in need of conservation due to widespread overexploitation. Based on precious few genetic and field observational studies, current speculation is that polyandrous mating strategies and multiple paternity may be common in sharks as they are in most other vertebrates. Here, we test this hypothesis by examining the genetic mating system of the bonnethead shark, Sphyrna tiburo, using microsatellite DNA profiling of 22 litters (22 mothers, 188 embryos genotyped at four polymorphic loci) obtained from multiple locations along the west coast of Florida. Contrary to expectations based on the ability of female S. tiburo to store sperm, the social nature of this species and the 100% multiple paternity observed in two other coastal shark species, over 81% of sampled bonnethead females produced litters sired by a single male (i.e. genetic monogamy). When multiple paternity occurred in S. tiburo, there was an indication of increased incidence in larger mothers with bigger litters. Our data suggest that sharks may exhibit complex genetic mating systems with a high degree of interspecific variability, and as a result some species may be more susceptible to loss of genetic variation in the face of escalating fishing pressure. Based on these findings, we suggest that knowledge of elasmobranch mating systems should be an important component of conservation and management programmes for these heavily exploited species.

©2004 Blackwell Publishing Ltd

Additional Comments
EPA grant #: E826128-01–0
Citation Information
Demian D. Chapman, Paulo A. Prodohl, James Gelsleichter, Charles A. Manire, et al.. "Predominance of Genetic Monogamy by Females in a Hammerhead Shark, Sphyrna tiburo: Implications for Shark Conservation" Molecular Ecology Vol. 13 Iss. 7 (2004) p. 1965 - 1974 ISSN: 0962-1083
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