Length-Weight Relationships, Condition Factor and Sex-Ratio of Nile Tilapia, Oreochromis niloticus in Wadi Hanifah, Riyadh, Saudi Arabia

The studies on length-weight relationships (LWR), condition factors (K) and sex-ratio of Nile tilapia, Oreochromis niloticus in Wadi Hanifah, Riyadh, Saudi Arabia was conducted from September 2011 to August 2012. A total of 575 specimens were collected from different sample stations using different types of net and by angling. The fishes were ranged from 76-273 mm, 69-261 mm and 69-273 mm in length for male, female and combined sex respectively, while weight ranged 14.8-430 g for male, 13.1-402 g for female and 13.1-430 g for combined sex. The values of regression coefficient for length-weight relationship are 3.16, 2.98 and 3.01 for male, female and combined sex respectively. This indicated that positive allometric growth for all sexes. The mean values of condition factor were calculated as 1.16, 1.02 and 1.09 for male, female and combined sex respectively that indicated healthy condition of fish. There is no significant different in male and female distribution of O. niloticus in Wadi Hanifah.