The aim of this work was to evaluate the spatial and temporal distribution of shrimp species in the Lake Nokoué-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 macrobrachion 13.81%, Macrobrachium vollenhovenii 5.36%, Penaeus monodon 2.68%, Macrobrachium felicinum 2.20%, Penaeus kerathurus 1.72%, Macrobrachium cf. zariquieyi 0.27%, and Macrobrachium equidens 0.27%. The species M. cf. zariquieyi and M. equidens were never reported from Benin, but are now found in Lake Nokoué. 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 Ouémé entrance) and north (near the Sô entrance) of the lake. Penaeus are strongly present in the lagoon complex from January to August, while Macrobrachium are more abundant in Lake Nokoué from September to December. Spearman’s correlation analysis revealed that increasing salinity, pH, transparency and total dissolved solids (TDS) positively influenced 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 management of the shrimp fishery, it is desirable that the shrimp fishery in Lake Nokoué, 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.

Amino Acids Composition of Maggot, Earthworm, Termite and Chicken Viscera Meals Used as Proteins Sources in Fish Feeding

Hoplobatrachus occipitalis is a frog belonging to Dicroglossidae family, the most spread in West Africa. This study aimed at performing to bibliographic synthesis on biology and ecology of this species in order to assess its potential in aquaculture. It lives along banks, rocky reservoirs and earthen ponds and prefers savannah areas. It feeds on coleopterans, caterpillars, spiders, vegetal fragments, fishes, crabs, ants, grasshoppers, locusts, dragonflies, frogs, mollusks, lizards, mice, butterflies, wasps and diptera larvae. The growth of H. occipitalis depend on the temperature and pH of the medium. A pH range 6.2 and 7 and temperature equal or upper, than 28 °C are suitable for its growth. H. occipitalis is an oviparous species. Its first sexual maturity height is 124.5 mm for females and 95 mm for males and it often reproduces during rainy season. The rapid growth, resistance and high nutritional quality of this species are some of its important potentialities for aquaculture. Natural reserves of H. occipitalis are overexploited and therefore no more able to satisfy the populations demand. A successful breeding of this species can help not only to preserve and strengthen the natural reserves but to produce regularly bulbous crowfoot for human consumption. Keywords: Hoplobatrachus occipitalis, biology, ecology, aquaculture potentialities.

Poultry eggs are considered an affordable and economical source of protein and energy available even in rural areas. The goal of this study was to assess and compare the effects of four different egg yolks on the growth performance and economic profitability of Clarias gariepinus larvae after vitelline resorption (3 days post hatch (DPH). Five experimental diets were tested. The control treatment (T0) consisted of Artemia cysts (zooplankton), while the other treatments included chicken egg yolk (T1), quail egg yolk (T2), guinea fowl egg yolk (T3), and turkey egg yolk (T4). The experimental design was a completely randomized design of 5 treatments with 3 replicates. The experiment lasted for 12 days. The larvae were fed five times a day. Interval sampling was conducted every four days. Growth parameters showed that treatment T0 (Artemia-fed larvae) achieved the highest biomass increase, rising significantly from 1006.66 ± 3.33 mg to 3533.33 ± 145.29 mg over the 12-day experimental period. Treatments T2 (quail egg yolk) and T4 (turkey egg yolk) demonstrated intermediate growth performance, while T1 (chicken egg yolk) and T3 (guinea fowl egg yolk) exhibited the lowest biomass gains, ranging from 1006.66 ± 6.66 to 1433.33 ± 33.33 mg and 1010.00 ± 2.88 to 1866.66 ± 66.66 mg, respectively. Survival rates showed no significant differences among T0, T2, and T4 (P > 0.05). Although T0 exhibited superior growth performance, it incurred a significantly higher economic conversion ratio, indicating increased feed cost per unit of biomass produced (P < 0.05). These findings suggest that while Artemia supplementation promotes rapid growth, its higher cost may affect overall economic efficiency compared to alternative egg yolk-based diets. Given the results on growth and survival performances as well as economic profitability, freeze-dried quail egg yolk and turkey egg yolk can be recommended for better optimization of C. gariepinus larval breeding mainly in rural conditions.

| The current study aims at evaluating the effect of experimental feed protein rate on growth and feed utilization in Hoplobatrachus occipitalis tadpoles. Six same-energy feed diets containing crescent protein rates (20, 30, 40, 45, 50 and 60 %) were formulated and tested on Hoplobatrachus occipitalis tadpoles though initial mean weight was 0.380 ± 0.004 g. Each diet was tested in triplicate for 24 days. 55 tadpoles was stocked per pond containing 30L water. Survival rates recorded ranged between 85.454 and 92.727% for all treatments. Growth and feed utilization parameters varied significantly with feed protein rate (P < 0.05). The best growth performances were recorded with 60% protein diet. According to the mathematical model (polynomial regression II) used for analysis of specific growth rate variations in relation to feed protein rate, optimal and maximal protein needs of Hoplobatrachus occipitalis tadpoles are 33 and 51% respectively. The highest protein rate of tadpoles’ carcass was noticed in tadpoles fed on 45% protein diet. The highest rate of lipid and dry matter was observed in tadpoles fed on 50% protein feed. The optimum and maximum protein requirements for better growth of H. occipitalis tadpoles are 38.30% and 54.10%, respectively.