Determination of Gillnet and Hook Selectivity for Caranx heberi Captured off Kanyakumari Coast of India

Large meshed gillnets having mesh sizes of 13.5 cm, 14 cm, 14.5 cm and 15 cm and Hooks No.5,6,7 and 8 were chosen for determining the selectivity and fishing power of the gears to capture the larger carangidCaranx heberi of Kanyakumari coast of India. The catch data were analysed using the software GILLNET (Generalized Including Log-Linear N Estimation Technique) comprised of the methodology of SELECT (Share Each Length Class Total) by fitting various uni-normal models viz., normal scale, normal location, log-normal, gamma and bi-normal model. Models were tested using various selectivity parameters like Model Deviance, Dispersion Parameter and residual plots. Bi-normal model was found appropriate for gillnet catch data while normal location for hook catch data despite over dispersion was common in both fits. The mesh size of 13.5 cm and hook No.5 and 6 were found as suitable mesh for capturing larger carangid.