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Biological parameters of swordfish in the Indian Ocean used for stock assessment

Biological parameters of swordfish in the Indian Ocean used for stock assessment. Growth parameters.

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Biological parameters of swordfish in the Indian Ocean used for stock assessment

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  1. Biological parameters of swordfish in the Indian Ocean used for stock assessment

  2. Growth parameters • Young, J., and A. Drake. 2004. Age and growth of broadbill swordfish (Xiphias gladius) from Australian waters. Final report for project 2001/014, Fisheries Research Development Corporation, Canberra, Australia. 121 pp. • A preliminary investigation of age and growth of swordfish, Xiphias gladius, from Western Australian waters using anal fin rays

  3. Growth parameters • Sampling area

  4. Growth parameters • Growth parameters (von Bertalanffy) • Female: L = 323.4; K = 0.08148; t0 = -3.413 • Male: L = 260.47 ; K = 0.1096 ; t0 = -3.3808

  5. Sex ratio • Young, J., and A. Drake (2004) y = 2E-10x5 - 2E-07x4 + 5E-05x3 - 0.0069x2 + 0.5153x - 14.662

  6. Length-Weight relationship • Ariz. J., A. Delgado de Molina, M. L. Ramos, and J. C. Santana, 2006. Analyses of sex ratio, by length-class and length-weight relationships for several species of Family Xiphiidae (Xiphias gladius, Linnaeus 1758) and Istiophoridae (Istiophorus platypterus, Shaw 1792) and Tetrapturus angustirostris, Tanaka 1915) caught from experimental cruise on Spanish longliners in the South Western Indian Ocean during 2005. The fifth meeting of the Working Party on Billfish (WPB), Indian Ocean Tuna Commission (IOTC), March 27–31, 2006. Colombo, Sri Lanka. IOTC-WPB-06-10, 14 pp.

  7. Length-Weight relationship • Sampling area

  8. Length-Weight relationship • Parameters (W = a  L b) • L: LJFL • Female: a = 2.413E-06, b = 3.33727 • Male: a = 1.351E-06, b = 3.45674 • Combined: a = 1.839E-06, b = 3.39209

  9. Sex ratio • Ariz. J., A. Delgado de Molina, M. L. Ramos, and J. C. Santana (2006).

  10. Sexual maturity • Poisson, F., and C. Fauvel, 2009. Reproductive dynamics of swordfish (Xiphias gladius) in the southwestern Indian Ocean (Reunion Island). Part 1: oocyte development, sexual maturity and spawning. Aquat. Living Resour., 22: 45-58.

  11. Sexual maturity • Sampling area

  12. Sexual maturity • %mature at length • %Mature females = 100[1/(1 + exp(16.2506 − 0.095342 LJFL))] • %Maturemales = 100[1/(1 + exp(10.1758 − 0.084884 LJFL))]

  13. Sexual maturity • %mature at length

  14. Sex ratio • Poisson, F., and C. Fauvel (2009). Y = −1.2×10−11 X6−1.2×10−8 X5 + 5 × 10−6 X 4 − 0.0011 X3 + 0.1355 X2 − 8.3638 X + 209

  15. Age-length key • The length distribution for each age group is assumed to be normal distributed with mean and SD. • Mean length and SD for each age group are estimated based on the parameters and data from Young, J., and A. Drake (2004).

  16. Age-length key • Length distribution for each age group (probability)

  17. Age-length key • Proportion that a fish with length X assigned to be a age X (age-length key)

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