Age, growth and stock structure of the oceanic whitetip shark, Carcharhinus longimanus, from the southwestern equatorial Atlantic

Between November 1992 and November 1997, 258 specimens (71.0-250.0 cm-TL) of Carcharhinus longimanus were collected off northeastern Brazil (Brazilian EEZ). Vertebral sections from 110 individuals, 44 males (71.0-235.5 cm), 60 females (81.0-230.0 cm) and six of undetermined sex (120.5-187.2 cm) were analyzed. Mean MIR analysis showed that one band is formed annually starting in August. Male and female growth is similar, back-calculated von Bertalanffy parameters were L(infinity) = 325.4 cm, K = 0.075 yr(-1) and t(0) = -3.342 yr(-1) for both sexes, whereas observed length-at-age parameters were L(infinity) = 284.9 cm; K = 0.996 yr(-1), and t(0) = -3.391 yr(-1). Observed length-at-age described growth better than back-calculated lengths. Maturity is reached for both sexes at 180.0-190.0 cm, or 6-7 year-old individuals. The overall sample ranged from a recently born male from the 0 age-class (71.0 cm) to a 17 year-old female (250.0 cm). Growth rates are 25.2 cm yr(-1) in the first free-living year, 13.6 cm yr(-1) from ages 1 to 4, 9.7 cm yr(-1) for adolescents of age 5 and 9.10 cm yr(-1) for mature individuals. The size-range of the overall sample is similar to others collected in different locations worldwide. The species follows the K-selected pattern like most elasmobranchs. (C) 1999 Elsevier Science B.V. All rights reserved.