Age and growth estimates for the dusky shark, Carcharhinus obscurus, were derived from vertebral centra collected in the northwestern Atlantic Ocean. Sample collection spanned the years prior to and following the implementation of management measures . Growth was compared pre-and post-population depletion and pre-and post-management to investigate the possibility of density-mediated shifts in age and growth parameters over time. There was no evidence of difference between periods for either sex. Additionally, bomb radiocarbon dating was used to determine the periodicity of band pair formation. Results support the traditional interpretation of annual band pairs up to approximately 11 years of age. After this time, vertebral counts considerably underestimate true age. Maximum validated ages were estimated to be between 38 and 42 years of age (an increase of 15 to 19 years over the band count estimates), confirming longevity to at least 42 years of age. Growth curves estimated using only validated data were compared to those generated using band pair counts. Logistic growth parameters derived from validated vertebral length-at-age data were L ∞ = 261.5 cm FL, L o =85.5 cm, t o =4.89 year and g= 0.15 year −1 for the sexes combined. Revised estimates of age at maturity were 17.4 years for males and 17.6 years for females.

Age and growth estimates for the Bull Shark Carcharhinus leucas were derived from 121 vertebral centra collected from Bull Sharks (59.1-223.5 cm FL) between 1966 and 2010 in the western North Atlantic Ocean. Size at birth was confirmed with an additional 20 embryos (44.2-54.4 cm FL). The maximum age based on vertebral band pair counts was 25 (184 cm FL) and 27 (196 cm FL) years for males and females, respectively. The logistic and Gompertz growth models fitted the size-at-age data best for males and females, respectively. Based on previously published estimates of length at maturity, males mature at 15-17 years (176-185 cm FL) and females at 15 years (189 cm FL). Bull Sharks in the western North Atlantic Ocean and the Gulf of Mexico have similar growth rates and reach similar sizes at age.

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