Variations Saisonnières Des Paramètres De Reproduction Et Relation Taille-Poids De Auxis thazard (Lacepède, 1800) Capturé Dans Le Golfe De Guinée Par La Flottille Artisanale Ivoirienne

Abstract

In this study, the seasonal variation in sex ratio, macroscopic stages of sexual maturity, gonado-somatic ratio, hepatostatic ratio, condition factor, and size-weight relationship in Auxis thazard from Gulf of Guinea were studied from January to December 2016. Sex ratio observed was in favor of males (1: 0,78; X² observed = 20,16 ˃ theoretical X² = 3,84 ; p ˂ 0,05). The variation of maturity stages associated with GSI, HSI, and K during different seasons of the year showed that this specie spawns throughout the year. Length-weight relationship was W = 0,0039 L 3, 4108 (R2 = 0,93 ; N = 291) for males, W = 0,0036 L 3, 4376 (R2 = 0,91 ; N = 227) for females, and W = 0,004 L 3, 4118 (R2 = 0,92 ; N = 519) for the combined sexes. The b value was significantly higher than the theoretical value of 3 for males (t-test, t = 233,218, p ˂ 0,05), for females (t-test, t = 227,776, p ˂ 0,05), and for all individuals (t-test, t = 315,821, p ˂ 0,05). This situation however indicates a faster increase of the fish in weight rather than in length.