Analysis of bomb radiocarbon data for common thresher sharks, Alopias vulpinus, in the northwestern Atlantic Ocean with revised growth curves

• Published in: Environmental biology of fishes Vol. 99; no. 1; pp. 39 - 47
• Main Authors: Natanson, Lisa J, Hamady, Li Ling, Gervelis, Brian J
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01.01.2016; Springer Nature B.V
• Subjects: Age; Alopias vulpinus; Animal populations; Animal Systematics/Taxonomy/Biogeography; Biomedical and Life Sciences; Environment; females; Freshwater & Marine Ecology; Life Sciences; longevity; males; Marine; Marine biology; Nature Conservation; periodicity; Radiocarbon dating; Sharks; Vertebrae; Zoology; Atlantic Ocean; ANW, Atlantic; Centra; Carbon-14; Vertebral column; Elasmobranchs; Age
• ISSN: 0378-1909; 1573-5133
• DOI: 10.1007/s10641-015-0452-y

Bomb radiocarbon dating was used to determine the periodicity of band pair formation in the vertebral centra of three common thresher sharks (Alopias vulpinus). The traditional interpretation of band pairs were accurate (i.e. annual) up to approximately 14 years of age. In older individuals, band pair counts underestimated age. A new maximum validated age was estimated to be 38 years (an increase of 18 years over the band count estimates). Previously reported length at age estimates for common thresher sharks up to 14 years were used in conjunction with the two older validated estimates to develop a revised growth curve for the species, which was described using the Schnute general model (sexes combined). Updated estimates of age at maturity remained the same for males (8 years) and increased by one year to 13 years for females. The primary finding was the increase in longevity for this species from a band pair count estimate of 24 years to a bomb radiocarbon validated estimate of 38 years, indicating this species lives much longer than previously thought.