UTTAR PRADESH JOURNAL OF ZOOLOGY

Papyrocranus afer are threatened by increasing collection from the wild for aquaria, especially the juveniles. Age, growth and growth derived parameters of P. afer Lagoon based on analysis Length Frequency Distribution (LFD) and interpretation of annual growth marks hard structures (namely scales, otoliths, opercula and cleithra).  In total, 1, 154 individuals of P. afer were sampled monthly during Jan. 2010 to Dec. 2011 from Lekki Lagoon. The mean lengths-at-ages from LFD were 13.45 cm (Age 0⁺) 34.45 cm (Age 1⁺), 49.50 cm (Age 2⁺) and 61cm (Age 3⁺). The von bertalanffy growth function was used to model the observed length-at-age data: L_t = 77.6 (1 – e^{-0.33(t +0.46)}). Length at first maturity (L_m) was 41.1cm while length at optimum yield (L_opt) was 49.5cm. Preponderance of immature fishes (38 cm) in the catch suggests growth overfishing. Interpretable annual growth marks on hard parts showed ages 1, 2 and 3 years; the mean lengths at these ages were 33.1, 44.6 and 58.4cm (cleithra), 29.1, 40.0 and 60.4 (scale) and 29.1, 40.0 and 60.4 (operculum). No interpretable growth marks on otoliths. Growth overfishing underline vulnerability of Papyrocranus afer to over-exploitation, hence the need for its conservation in Lekki Lagoon.