Age and growth of the tiger shark, Galeocerdo cuvier (Péron & Lesueur, 1822) from the equatorial South Atlantic Ocean

Age and growth in the tiger shark, Galeocerdo cuvier , were estimated from vertebral analysis of specimens collected in Brazil. A total of 221 sharks (82 to 426.3 cm total length - L _T ) were measured, and among these sharks, vertebrae were collected from 67 individuals, and more 9 of embryos (68 - 77 cm L _T ) were added to total sample for analysis. Monthly mean marginal increment and the frequency of opaque rings in the edge of vertebrae did not allow the observation of periodicity; nonetheless, growth bands were considered to be annual. No significant differences in size, age or growth were found between sexes. Based on the Akaike Information Criterion ( AIC ), the von Bertalanffy model was the most adequate to describe the growth of G. cuvier . The estimated parameters for both sexes were: L _∞ = 401.2 cm L _T , k = 0.255 year ^-1 and t ₀ = -1.08 years. The age of sampled individuals ranged between 0 and 13.5 years, with sexual maturation being estimated at 310 cm L _T or 4.7 years. Overall, the species exhibited rapid growth, particularly during the juvenile stage. Differences in sizes and ages were found in specimens suggesting an ontogenetic habitat shift from coastal to oceanic waters.