Reflecting onto the population dynamics of Hydrocynus brevis from Dadin: Kowa Reservoir

Abstract

The population dynamics of Hydrocynus brevis from Dadin-Kowa reservoir were studied. Population dynamic parameters such as growth, mortality and recruitment patterns were analyzed using length frequency data over 12-month period employing FiSAT II software. Findings revealed that K = 1.7-yr., L∞ = 33.33 cm and Tmax = 1.76 years. Mortality indices revealed that the fish is slightly above exploitation threshold (F > Eopt ≤ 0.5). However; the major source of population decay is associated with natural factors (M = 2.87-yr.). Bimodal recruitment pulses were observed with Lm = 22.9 cm, Lc/ L∞ = 0.29. Restocking program is suitable to ensure its continuous existence as it seems to have low population, and experiencing recruitment overfishing.