DISTRIBUTION MODEL OF SHRIMP SPECIES IN LAKE NOKOUe, SOUTHERN BENIN, WEST AFRICA

The aim of this work was to evaluate the spatial and temporal distribution of shrimp species in the Lake Nokoue-Cotonou Channel complex for an efficient management of the fishery. The results of one year sampling from five stations (North, South, East, Central and West) in the complex revealed the following proportions: Penaeus notialis 73.68%, Macrobrachium macrobra-chion 13.81%, Macrobrachium vollenhovenii 5.36%, Penaeus monodon 2.68%, Macrobrachium felicinum 2.20%, Penaeus kerathurus 1.72%, Macrobrachium cf. zariquieyi 0.27%, and Macro -brachium equidens 0.27%. The species M. cf. zariquieyi and M. equidens were never reported from Benin, but are now found in Lake Nokoue. Spatially, Penaeus (Penaeus notialis) are more abundant in the west (Acadja concentration zone), while Macrobrachium (Macrobrachium macrobrachion) are more dominant in the east (near the Oueme entrance) and north (near the So entrance) of the lake. Penaeus are strongly present in the lagoon complex from January to August, while Macrobrachium are more abundant in Lake Nokoue from September to December. Spearman's correlation analysis revealed that increasing salinity, pH, transparency and total dissolved solids (TDS) positively influ-enced the abundance of P. notialis, while increasing salinity, pH, transparency, and TDS negatively influenced the abundance of M. macrobrachion at the 5% significance level. For an efficient man-agement of the shrimp fishery, it is desirable that the shrimp fishery in Lake Nokoue, mainly in the Cotonou Channel, which is a very sensitive area for their seasonal migrations, benefits from at least three months of respite per year, from November to January. This period corresponds to the strong migration of juvenile Penaeus towards the lake. This should allow many Penaeus to grow up and breed at least once in their lives, according to the species life cycle presented.