Abstract
Intra-species plasticity in the life-history characteristics of sharks leads to the need for regional estimates to accurately determine resilience to anthropogenic effects. The present study provides the first length-At-Age, growth and maturity estimates for the bronze whaler (Carcharhinus brachyurus) from southern Australia. Age estimates were obtained from vertebral sections of 466 individuals spanning 50-308-cm total length. Maximum estimates of age for males and females were 25 and 31 years respectively. The three-parameter logistic model for females (L∞≤308cm LT, k≤0.15, ≤742) and for males (L∞≤317cm LT, k≤0.13, ≤782) provided the best fit to the size at age data. Males matured at a similar age (16 years), but smaller size than females (224v. 270cm LT). Growth parameters and age-At-maturity estimates were similar to those for genetically isolated C. brachyurus populations, and the sympatric dusky shark (C. obscurus). The southern Australian C. brachyurus population is long-lived, slow growing and late maturing. These growth parameters are needed to undertake demographic analyses to assess the resilience of C. brachyurus to fishing, and provide an example of a wide-ranging elasmobranch with similar life-history characteristics across isolated populations.
Original language | English |
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Pages (from-to) | 461-472 |
Number of pages | 12 |
Journal | Marine and Freshwater Research |
Volume | 68 |
Issue number | 3 |
Early online date | 16 May 2016 |
DOIs | |
Publication status | Published - 2017 |
Keywords
- age and growth
- copper shark
- fisheries
- reproduction
- South Australia.