This work was carried out with the aim of analyzing the growth parameters of Hepsetus odoe (Bloch, 1794) caught in the Ebrié lagoon with a view to contributing to the conservation and sustainable management of this fish. A total of 220 fish from commercial artisanal fishing were sampled from July 2022 to June 2023 in sector IV of the Ebrié lagoon. Each specimen was weighed and measured to the nearest gram and millimeter respectively. The length-weight relationship and the condition factor were calculated. The data collected were processed on Excel and Statistica 7.1 software. The size of the individuals varies from 11.2 to 36 cm and the weight oscillates between 10.2 and 196 g. The size frequency distribution is unimodal ([17; 20 [cm). In general, growth is of the positive allometry type regardless of sex and size. It appears that the species is gaining weight faster than it is growing. In males and females the mean value of the condition factor K is 0.638 ± 0.02 and 0.700 ± 0.014 respectively. These individuals are not overweight in their biotope regardless of their sex and size.
Pseudotolithus elongatus of the family of Sciaenidae lives in Ebrie lagoon, where it is regularly met in the unloadings of artisanal fishing. The diet was studied according to the seasons and of the size of the various specimens (immature and mature). About 437 individuals of measuring between 14,5 and 42,7 cm total length were examined during July 2013 to February 2015. On the 437 examined stomachs, 182 were empty, which gives a rate of vacuity of 41,64%. A feeding index (IRI: index of relative importance of food item) by combining three methods (frequency occurrence, numerical method and weight method) was used. The identification of the items found the stomach contents revealed that the principals food items were the Crustacean (%IRI = 89,26) and the fish (%IRI = 10,54). Annelids (%IRI = 0,1) and the vegetable detritus (%IRI = 0,1) are accidental food. This feed does not varied seasonally and among the size of fish.
The diet of 233 specimens of Heterotis niloticus (Cuvier, 1829) coming from artisanal fishing on the Agneby river was studied during one year according to the hydrological seasons and the size of fish. The stomach contents were analysed by using the methods of frequency of occurrence, numerical frequency and specific abundance. The results obtained reveal that this fish is omnivorous because its diet contains insects, microcrustacea, rotifer, nematodes, Arachnida, molluscs, seeds, phytoplankton, detritus and sand. It mainly fed on microcrustacea in particularly ostracoda. However, there is not variation in the diet according to the hydrological seasons and size of the individuals.
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