Age validation of great hammerhead shark (Sphyrna mokarran), determined by bomb radiocarbon analysis

作者：Passerotti Michelle S^*; Carlson John K; Piercy Andrew N; Campana Steven E

来源：Fishery Bulletin, 2010, 108(3): 346-351.

Preliminary validation of annual growth band deposition in vertebrae of great hammerhead shark (Sphyrna mokarran) was conducted by using bomb radiocarbon analysis. Adult specimens (n=2) were collected and thin sections of vertebral centra were removed for visual aging and use in radiocarbon assays. Vertebral band counts were used to estimate age, and year of formation was assigned to each growth band by subtracting estimated age from the year of capture. A total of 10 samples were extracted from growth bands and analyzed for Delta C-14. Calculated Delta C-14 values from dated bands were compared to known-age reference chronologies, and the resulting patterns indicated annual periodicity of growth bands up to a minimum age of 42 years. Trends in Delta C-14 across time in individual specimens indicated that vertebral radiocarbon is conserved through time but that habitat and diet may influence Delta C-14 levels in elasmobranchs. Although the age validation reported here must be considered preliminary because of the small sample size and narrow age range of individuals sampled, it represents the first confirmation of age in S. mokarran, further illustrating the usefulness of bomb radiocarbon analysis as a tool for life history studies in elasmobranchs.

• 出版日期2010-7