Reproduction of the threadfins of the costal shelf of Grand-Lahou was studied with a monthly sampling frequencies range from may 2009 to april 2011. 534 specimens of Polydactylus quadrifilis, composed of 315 males and 219 females and 648 Galeoides decadactylus composed of 420 males and 228 females, then 453 individuals of Pentanemus quinquarius composed of 210 males and 243 females were used. The sexual maturity parameters of threadfins fishes indicate a size of first maturity (L50 = 67.5 cm) for females of Polydactylus quadrifilis and (L50 = 55.5 cm) with their males. Concerning  the specimens of Pentanemus quinquarius, females present (L50 = 15 cm) and their males (L50 = 14.5 cm). This parameter has identical values ​​with the females of Galeoides decadactylus (L50 = 15.5 cm) and their males (L50 = 15.5 cm). The individuals of Polydactylus quadrifilis and the specimens of Galeoides decadactylus and Pentanemus quinquarius become mature at 1 year of age. The sex ratio determination show that specimens of Polydactylus quadrifilis show a predominance of males during the warm season, from October (73.68%) to March (64.28%) which weakens during the cold season, from May (30%) to July (58%). For Galeoides decadactylus, the sex ratio shows a predominance of males, from August (88%) to March (94.73%). Concerning specimens of Pentanemus quinquarius, the sex ratio is in favor of the females whose lowest value is during the cold season in July (21.74%). All threafin species reach sexual maturity from their first year of life with different sex ratios variations.

In northern Côte d'Ivoire, fishing is mainly practiced in agro-pastoral Dam Lakes. Previous studies on some of them indicated the possibility to increase their exploited production. This study was conducted from October 2018 to September 2019 on the Solomougou Dam Lake. Its objectives are to study the intensity of fishing activity and the rate of exploitation of this fishery. It appears that fishing is practiced throughout the year on this lake. However, 54.54% of fishermen stay there less than 6 months, also exploiting other fisheries in the region. Less frequented from August to October, its colonization gradually increases from November to reach the peak in March. Fishing gears are used seasonally. In fact, traps and gillnets are less used respectively during low water and flood periods of the Dam Lake. Sparrow hawks, less used by fishermen, are however used throughout the year while the use of longlines, bamboo traps and seine nets is limited to a few months. In terms of exploitation of the fishery, a density of 6.6 fishermen per km2 would be observed in a situation of full exploitation indicating a state of overexploitation of the fishery. However, taking into account fluctuations of fishermen's number per month, their densities ranged between 0.8 and 2.6 fishermen per km2 from July to December, indicative of normal exploitation of the fishery and between 3.2 and 4.2 fishermen per km2 outside this period, a little above the recommended standards.

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Pseudotolithus elongatus est un poisson régulièrement rencontré dans les débarquements de la pêche artisanale et commerciale pratiquée en lagune Ebrié. Cependant, en Côte d’Ivoire aucune étude n’a encore été menée sur cette espèce bien qu’elle ait une valeur commerciale élevée et qu’elle soit beaucoup prisée par la population. Du fait de l'intérêt commercial que présente P. elongatus, l'étude de sa reproduction est nécessaire si l'on souhaite assurer la pérennité de l’espèce et satisfaire le consommateur. L’étude de la morphologie et de l’histologie des gonades a été basée sur la taille, la forme, la coloration la présence ou l’absence d’ovocytes mûrs, le diamètre des ovocytes et l’observation histologique. Les résultats obtenus ont révélé six stades de maturation des gonades avec une gamétogenèse continue observée chez cette espèce. L’ensemble de ces informations contribueront à pérenniser l’espèce par une gestion rationnelle du stock.   English title: Morphological and histological characteristics of the gonads of pseudotolithus elongatus (Bowdich, 1825), from Ebrié lagoon, Côte d’Ivoire Pseudotolithus elongatus is a fish regularly met in the landings of the artisanal and commercial fishing on Ebrie lagoon. However, in Ivory Coast no study has been conducted on this species although it has a high commercial value and it is very appreciated by the people. Because of the commercial interest of P. elongatus studying its reproduction is necessary if one wishes to improve operations in order to ensure the sustainability of the species and satisfy the consumer. The studies of gonads morphology and histology of Pseudotolithus elongatus was based on the size, shape, staining of the gonads, the presence or absence of ripe oocytes, the diameter of the oocytes and the histological observation. The results obtained indicate six stages of gonad maturation with continuous gametogenesis observed in this species. All of this information will contribute to perpetuate this species through rational management of the stock.