Some reproductive aspects of Engraulis encrasicolus (Engraulidae) from artisanal fishing in Eastern coast of Ivory Coast

Some aspects of the cycle of reproduction of the anchovy (Engraulis encrasicolus) resulting from artisanal fishing were studied from September 2004 to March 2006. Samplings were carried out in campings and villages, along the littoral of Ivory Coast where the seines of beach and the purse seines sliding are used for small-scale fishing in the depths from 6 to 10 m. The sex-ratio is 1:1.2 in favour of the males. The size of the first sexual maturity (L50) is 8.4 cm in the male against 8.8 cm in the female. The length-weight equation indicates that length increases more than weight (b = 2.5953 < 3). The macroscopic examination of the gonads showed that the species is immature between October and September (stages I and II). In November, the gonads were at the beginning of maturation (stage III) and maturation went on through December and January (stage IV) to reach in February and March stage V. The gonado-somatic index, was weak (0.09-2%) during September- October, increased gradually to reach maximum value (6-7%) in March when spawning can occur. The means of absolute and relative fecundities are 14 616 c 6146 oocytes and 1587 oocytes per gram of body weight, respectively. A linear relation was found between fecundity and total weight. Beyond the depths of 10 m no specimen of E. encrasicolus was captured during May to August.Original Abstract: Quelques aspects du cycle de reproduction de l'anchois (Engraulis encrasicolus) de la peche artisanale ont ete etudies de septembre 2004 a mars 2006. Les echantillonnages ont ete realises dans des campements et villages, le long du littoral ivoirien ou les sennes de plage et les sennes tournantes coulissantes constituent les engins de la peche artisanale utilises pour la capture de ces poissons entre 6 a 10 m de profondeur. La sex-ratio globale observee est de 1:1,2 en faveur des males. La taille de premiere maturite sexuelle (L50) est de 8,4 cm chez le male contre 8,8 cm chez la femelle. La croissance en poids en fonction de la longueur (LF), regie par la loi de croissance relative, est exprimee de maniere formelle par une equation qui revele que la taille croit plus vite que le poids (coefficient de regression = b = 2,5953 < 3). L'examen macroscopique des gonades a montre que l'espece est immature (stades I et II ) entre les mois de septembre et octobre. Au mois de novembre, les gonades sont en debut de maturation (stade III), laquelle se poursuit en decembre et en janvier (stade IV). A partir des mois de fevrier e