Register      Login
Marine and Freshwater Research Marine and Freshwater Research Society
Advances in the aquatic sciences

Age and growth of the great hammerhead shark, Sphyrna mokarran, in the north-western Atlantic Ocean and Gulf of Mexico

Andrew N. Piercy A , John K. Carlson B C and Michelle S. Passerotti B
+ Author Affiliations
- Author Affiliations

A Florida Program for Shark Research, Florida Museum of Natural History, University of Florida, PO Box 117800, Gainesville, FL 32611, USA.

B NOAA/National Marine Fisheries Service, Southeast Fisheries Science Center, 3500 Delwood Beach Road, Panama City, FL 32408, USA.

C Corresponding author. Email:

Marine and Freshwater Research 61(9) 992-998
Submitted: 9 September 2009  Accepted: 10 February 2010   Published: 23 September 2010


The great hammerhead shark, Sphyrna mokarran, is a cosmopolitan species that is caught in a variety of fisheries throughout much of its range. The apparent decline of great hammerhead shark populations has reinforced the need for accurate biological data to enhance fishery management plans. To this end, age and growth estimates for the great hammerhead were determined from sharks (n = 216) ranging in size from 54- to 315-cm fork length (FL), captured in the Gulf of Mexico and north-western Atlantic Ocean. Growth curves were fitted using multiple models and evaluated using Akaike’s information criterion. The von Bertalanffy growth model was the best fitting model, with resulting growth parameters of L = 264.2-cm FL, k = 0.16 year–1, t0 = –1.99 year for males, and L = 307.8-cm FL, k = 0.11 year–1, t0 = –2.86 year for females. Annual band pair deposition was confirmed through marginal-increment analysis and a concurrent bomb radiocarbon validation study. Great hammerheads have one of the oldest reported ages for any elasmobranch (44 years) but grow at relatively similar rates (on the basis of von Bertalanffy k value) to other large hammerhead species from this region. The present study is the first to provide vertebral ages for great hammerheads.

Additional keyword: von Bertalanffy.


We thank NOAA Fisheries observers and Florida Program for Shark Research scientists for assistance with collection of shark specimens for this study. We extend our gratitude to the numerous student interns and volunteers for helping with the preparation of vertebrae. We thank two anonymous reviewers who provided valuable comments on this manuscript. A portion of the funding for this project was contributed by the National Marine Fisheries Service’s Highly Migratory Species Division through the Florida Program for Shark Research, a member institution in the National Shark Research Consortium.


Abercrombie, D. L. , Clarke, S. C. , and Shivji, M. S. (2005). Global-scale genetic identification of hammerhead sharks: application to assessment of the international fin trade and law enforcement. Conservation Genetics 6, 775–788.
Crossref | GoogleScholarGoogle Scholar | CAS | Burnham K. P., and Anderson D. R. (2002). ‘Model Selection and Multimodel Inference: A Practical Information-Theoretic Approach.’ 2nd edn. (Springer: New York.)

Cailliet G. M., and Goldman K. J. (2004). Age determination and validation in chondrichthyan fishes. In ‘The Biology of Sharks and Their Relatives’. (Eds J. Carrier, J. A. Musick and M. Heithaus.) pp. 399–447. (CRC Press: Boca Raton, FA.)

Cailliet, G. M. , Mollet, H. F. , Pittenger, G. G. , Bedford, D. , and Natanson, L. J. (1992). Growth and demography of the Pacific angel shark (Squatina californica), based on tag returns off California. Australian Journal of Marine and Freshwater Research 43, 1313–1330.
Crossref | GoogleScholarGoogle Scholar | Camhi M. D. (1998). ‘Sharks on the Line: A State-by-State Analysis of Sharks and Their Fisheries.’ (National Audubon Society: New York.)

Camhi M. D., Valenti S. V., Fordham S. V., Fowler S. L., and Gibson C. (2009). ‘The Conservation Status of Pelagic Sharks and Rays: Report of the IUCN Shark Specialist Group Pelagic Shark Red List Workshop.’ (IUCN Species Survival Commission Shark Specialist Group: Newbury, UK.)

Campana, S. E. , Natanson, L. J. , and Myklevoll, S. (2002). Bomb dating and age determination of large pelagic sharks. Canadian Journal of Fisheries and Aquatic Sciences 59, 450–455.
Crossref | GoogleScholarGoogle Scholar | Compagno L. J. V. (1984). FAO species catalogue. Sharks of the world. An annotated and illustrated catalogue of shark species known to date. Part 2: Carcharhiniformes. FAO Fisheries Synopsis No. 125, Vol. 4, Part 2. FAO, Rome.

Conrath, C. C. , Gelsleichter, J. J. , and Musick, J. A. (2002). Age and growth of the smooth dogfish (Mustelus canis) in the northwest Atlantic Ocean. Fishery Bulletin 100, 674–682.
Garza Gisholt E. (2004). Edad y crecimiento de Sphyrna zygaena (Linnaeus 1758) en las costas de Baja California Sur, México. Thesis, Universidad Autónoma de Baja California Sur, Área Interdisciplinaria de Ciencias del Mar, La Paz, Mexico.

Goldman K. J. (2002). Aspects of age, growth, demographies, and thermal biology of two lamniform shark species. Ph.D. Thesis, College of William and Mary, Virginia Institute of Marine Science, Gloucester Point, VA.

Goosen, A. J. , and Smale, M. J. (1997). A preliminary study of the age and growth of the smoothhound shark Mustelus mustelus (Triakidae). South African Journal of Marine Science 18, 85–91.
Hale L. F., Gulak S., and Carlson J. K. (2009). Characterization of the shark bottom longline fishery, 2008. NOAA Technical Memorandum NMFS-SEFSC-586.

Hoenig, J. M. , Morgan, M. J. , and Brown, C. A. (1995). Analysing differences between two age determination methods by tests of symmetry. Canadian Journal of Fisheries and Aquatic Sciences 52, 364–368.
Crossref | GoogleScholarGoogle Scholar | NSRC (National Shark Research Consortium) (2007). Highly migratory shark fisheries research by the National Shark Research Consortium 2002–2007. Mote Marine Laboratory Technical Report No. 1241. Mote Marine Laboratory, Sarasota, FL.

Passerotti, M. S. , Carlson, J. C. , Piercy, A. N. , and Campana, S. E. (2010). Age validation of great hammerhead shark (Sphyrna mokarran), determined by bomb radiocarbon analysis. Fishery Bulletin 108, 346–351.
Sadowsky V. (1971). First record of the occurrence of an adult hammerhead shark (Sphyrna mokarran) in southern Brazilian waters. Contribuicoes Avulsas do Instituto Oceanografico 24, 1–3. [Oceanografia Biologica].

Schwartz, F. J. (1983). Shark ageing methods and age estimation of scalloped hammerhead, Sphyrna lewini, and dusky, Carcharhinus obscurus, sharks based on vertebral ring counts. NOAA Technical Report NMFS 8, 167–174.
Springer S. (1963). Field observations on large sharks of the Florida–Caribbean region. In ‘Sharks and Survival’. (Ed. P. W. Gilbert.) pp. 95–113. (Heath & Co.: Boston, MA.)

Stevens, J. D. , and Lyle, J. M. (1989). Biology of three hammerhead sharks (Eusphyra blochii, Sphyrna mokarran and S. lewini) from Northern Australia. Marine and Freshwater Research 40, 129–146.
Crossref | GoogleScholarGoogle Scholar |

Strong, W. R. , Snelson, F. F. , and Gruber, S. H. (1990). Hammerhead shark predation on stingrays: an observation of prey handling by Sphyrna mokarran. Copeia 1990, 836–840.
Crossref | GoogleScholarGoogle Scholar |

Tolentino, V. A. , and Mendoza, C. R. (2001). Age and growth for the scalloped hammerhead shark, Sphyrna lewini (Griffith and Smith, 1834) along the central Pacific coast of Mexico. Ciencias Marinas 27, 501–520.

Trent, L. , Parshley, D. E. , and Carlson, J. K. (1997). Catch and bycatch in the shark drift gillnet fishery off Georgia and Florida. Marine Fisheries Review 59, 19–28.

Van Dykhuizen, G. , and Mollet, H. F. (1992). Growth, age estimation, and feeding of captive sevengill sharks, Notorynchus cepedianus, at the Monterey Bay Aquarium. Australian Journal of Marine and Freshwater Research 43, 297–318.
Crossref | GoogleScholarGoogle Scholar |

von Bertalanffy, L. (1938). A quantitative theory of organic growth (inquiries on growth laws. II). Human Biology 10, 181–213.