Growth, mortality and yield per recruit of the rabbit fish Siganus rivulatus (Forsskål 1775) in the red sea coast of Jeddah, Saudi Arabia

Abstract

The yield per recruit of Siganus rivulatus in Jeddah fisheries was estimated based on growth parameters and mortality coefficients investigated during the period from April 2013 to May 2014. Growth rates and von Bertallanfy growth parameters were estimated based on age determination using otoliths. The estimated growth parameters were L∞ = 38.1 cm, K = 0.275 and t0 = -0.24 year. The length weight relationship could be described by the equation: W = 0.011 L3.06. Mortality coefficients were estimated as total coefficient 'Z' = 2.04 year-1, natural coefficient 'M' = 0.413 year-1, and fishing coefficient 'F' = 1.627 year-1. The exploitation level 'E' was estimated to be 0.8 year-1. The yield per recruit estimated at the current level of fishing mortality was 66.715 gm. The maximum yield per recruit (67.8 gm) can be obtained by reducing the current level of fishing mortality to be Fmax = 1.0 year-1. These results indicated that the stock of Siganus rivulatus in Jeddah fisheries is currently overexploited.