Length–length relationship, length–weight relationship, gonadosomatic index, condition factor, size at maturity and fecundity of Parastromateus niger (Carangidae) in Kuwaiti waters

Abstract

Summary Analyses of morphometric parameters of the black pomfret, Parastromateus niger, in the Kuwaiti waters of the Arabian Gulf during a 44-month study revealed the following length-length relationships: TL (cm) = 0.63 + 1.15SL (females), TL (cm) = 0.94 + 1.14SL (males) and TL (cm) = 0.75 + 1.15SL (both sexes including juveniles). The 95% CI of the exponent in length-weight relationship varied from 2.788 to 2.796 in females, 2.726 to 2.732 in males, 2.779 to 2.784 for both sexes and 2.590 to 2.613 in juveniles, all indicating an allometric relationship. Simultaneous analysis of Fulton’s condition factor (K) and GSI indicate that spawning in black pomfret peaks in May and June even though the fish remain in good condition throughout the spawning season. The Fulton’s condition factor was statistically discriminatory in determining the well-being of P. niger. Variation in average maximum condition was significant between sexes and also higher in 2004 as compared to 2005. The mean size at first sexual maturity (SL50%) was 17.5 cm for males and 29 cm for females. Fecundity ranged from 71 305 to 3 895 449 eggs and correlated positively with: (a) ovary-free body weight (P 0.05). Fecundity-total length relationship was best described by the logarithmic equation of the form F = 0.898 + 3.15 × TL3.15. The use of results of such morphometric studies in the management of the P. niger species in the Arabian Gulf is suggested due to its growing commercial importance.