| Summary: | Growth and Exploitation Parameters of Chrysichthys nigrodigitatus Lecepede, 1803) (Siluriformes, Bagridae) in a Tropical Lagoon: Ebrié lagoon (Potou Lagoon Sector, Ivory Coast). The growth and exploitation parameters of Chrysichthys nigrodigitatus (Lecepede, 1803) have been studied for the first time in the lagoon Ebrié (sector Aghien-Potou). A total of 1038 individuals with size ranging from 80 to 410 mm (Average: 204.7 mm) have been examined during this survey. Growth parameters of C. nigrodigitatus as the asymptotic length (L∞), the growth rate (K) and the growth performance index (Ø') were respectively 53 cm, 0.33 year-1 and 2.968. The theoretical age of C. nigrodigitatus (t0) at length zero was estimated to -0.69 while the maximum age (or longevity, tmax) was estimated to 9.09 year. The values of the total mortality coefficients (Z), natural mortality (M) and fishing mortality rate (F) as well as the exploitation rate (E) of C. nigrodigitatus were respectively 1.79 year-1, 0.73 year-1, 1.73 year-1, and 0,59. This study shows that in the sector Potou of the Ebrié lagoon, C. nigrodigitatus is subjected to a fishing mortality (1.73 year-1) far superior to the natural mortality (0.73 year-1). Besides, C. nigrodigitatus is overfished with exploitation rate (E = 0.59) superior to the maximal exploitation rate (Emax) to 0.414.
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