Biological parameters of European hake from the coastline of Mostaganem (Northern West Algeria)

Abstract

Hake is an important species of economic interest and thus the subject of a large literature, but its biology parameters which are essential for stock assessment and management remains insufficiently known. The aim of this paper was, therefore, to describe the growth, lengthË—weight relationship and reproduction of Merluccius merluccius in the Algerian western coast. Consequently, we studied growth and estimated age, using the lengthË—weight relationship was determined according to the allometric equation (Sparre et al., 1989) and the growth of M. merluccius was estimated computing the Von Bertalanffy growth equation (VBGF) (Beverton et Holt, 1957).The gonadosomatic index (GSI) was calculated monthly by the equation: GSI = (gonad weight/fish weight without gonad)*100. Size at maturity (L50) was defined as the size at which 50% of individuals were mature. The femaleË—male ratio was 1.14: 0.88. The total length and weight of females ranged from 24 cm to 33.7 cm and 104.94 g to 270.29 g respectively and for males was 23.7 cm to 34.8 cm and 95.4 g to 292.07 g. The growth parameters for males were cal-culated as L∞=34.80 cm k= 0.470 year-1, t0= -1.49 year and for females L∞= 35.70 cm, k= 0.360 year-1, t0= -2.76 year. The length–weight relationship was W= 0.024*L2.648for female and W= 0.012*L2.828 for Male. Monthly values of the gonadosomatic index indicated that spawning occurred mainly in December, January and February. The result of the present work will be a step forward to the improvement of the fisheries assessment and management of M. merluccius in this area.