Computed model for various mesh sizes using the method described by Sparre and Venema (1998). A common selection factor was also estimated. The length at first maturity and the length at 50% maturity (Lm) of female shark catfish were estimated elsewhere using Thapanand’s method (Thapanand, per. com.) and Matson’s Formula (Matson, 1997). Optimum mesh size for shark catfish gillnetting was decided by Comparing the Lc with Lm.