Some biological aspects of the Por’s goatfish, (Family: Mullidae) from Tripoli Cost of Libya

The age, growth parameters, spawning season, sex ratio, length at first sexual maturity and fecundity of Por’s goatfish (Upeneus pori – Mullidae) caught from Tripoli coast in the Southern Mediterranean Sea were investigated.Females constitute about 51.9% of the species population in which the total fish length ranged from 7.0 to 17.5 cm. The length–weight relationship for males and females were expressed as W = 0.0107 × L2.99 and W = 0.01055 × L3.001, respectively. The age data derived from the scale readings were used to estimate the growth parameters of the von Bertalanffy growth equation. The estimated parameters were: L∞ = 211.5 mm, K = 0.2504 and t0 = −1.7073 for females, and L∞ = 210.2 mm, K = 0.2724 and t0 = −1.4421 was for males. The maximum age was 5 years old and the 2-year age group dominated the U. pori population. It was found that, males and females matured at a total length of about 10 cm. The monthly variations of the gonado-somatic index indicated that the spawning occurred mainly between May and July. The fecundity–length relationship was expressed as F = 2.107*L3.579.