Age and growth of yellowtail snapper, Ocyurus chrysurus, from the southeastern United States
2003; Rosenstiel School of Marine and Atmospheric Science; Volume: 72; Issue: 3 Linguagem: Inglês
ISSN
1553-6955
AutoresEden R. Garcia, Jennifer C. Potts, Roger A. Rulifson, Charles S. Manooch,
Tópico(s)Fish Ecology and Management Studies
ResumoSagittal otoliths were collected from 1528 yellowtail snapper, which were obtained from commercial and headboat fisheries during 1994-1999 in Daytona Beach, Florida through Key West, Florida and the Dry Tortugas. The oldest yellowtail snapper was 13 yrs old and the largest fish was 561 mm fork length (FL) [700 mm total length (TL)]. Marginal increment analysis revealed the opaque zones to be true annuli formed in spring. The relations of TL to FL were described by the following equations: TL = 9.96 + 1.20(FL) and FL = 7.56 + 0.79(FL). The weight-length relations were described by the equations: W = 4.14 × 10 -5 FL 2.83 and W = 3.64 × 10 -5 TL 2.76 , where W = weight (g). The length-otolith radius relations were best described by the equations: FL = -50.9 + 10.4(R c ) and TL = -70.3 + 13.0(R c ), where R c = otolith radius in micrometer units. Mean back-calculated fish lengths for given ages ranged from 132 mm FL (160 mm TL) for age 1 to 516 mm FL (638 mm TL) for age 13. Theoretical growth was best described by the von Bertalanffy growth equation: FL t = 483.8(1 - e -0.17 (t+1.87) ) and TL = 607.7(1 - e -0.17(t+1.88) ) where t = age in years. Fish lengths at specific ages were similar to those reported almost 20 yrs ago. The pooled instantaneous total mortality rate (Z) for all fish ages 3-13 in was 0.64 ( n = 1484). Modal ages for yellowtail snapper caught in the commercial and headboat fisheries were ages 2 and 3 respectively. Overall, the structure and growth of the yellowtail snapper stock off southern Florida has not changed in two decades of heavy fishing; although, fewer older fish were detected in our study.
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