Stock assessment of the African moony, Monodactylus sebae (Cuvier, 1829) in the New Calabar, Nigeria

The population biology and stock assessment of African moony, Monodactylus sebae was studied based on monthly length frequency data collected from New Calabar River, Nigeria from February 2020 to March 2021. The estimated von Bertalanffy growth parameters were growth performance index (2.91 per year), asymptotic length (L∞ = 36.54 cm) and growth curvature (K = 0.61yr^-1). The estimated theoretical age at birth (t0) and longevity for the assessed fish species were 0.55 years and 2.91 years, respectively. The total mortality (Z), natural mortality (M), and fishing mortality (F), were 1.87 year^-1, 1.23 year^-1 and 0.64 0.64 year^-1, respectively. The length at first capture (Lc) was 8.56 cm. The exploitation rate (E) and maximum exploitation rate (Emax) were calculated as 0.34 and 0.36, respectively. The recruitment pattern occurs throughout the year, with only one major peak in May with 19.9% recruits. Emax was 0.36, while E50 was 0.23 indicating that the current exploitation rate was below the maximum sustainable yield, showing that this stock was underexploited.