Age, growth and stock structure of the oceanic whitetip shark, Carcharhinus longimanus, from the southwestern equatorial Atlantic
Abstract
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 ∞ = 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 ∞ = 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.
- Publication:
-
Fisheries Research
- Pub Date:
- January 1999
- DOI:
- 10.1016/S0165-7836(99)00045-4
- Bibcode:
- 1999FishR..42...21L
- Keywords:
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- Sharks;
- Elasmobranchs;
- Carcharhinus longimanus;
- Carcharhinus maou;
- Southern Atlantic;
- Age and growth