Studies on the population dynamics of Pellonula leonensis (Clupeidae) in the Cross River, Nigeria

Abstract

Based on length-frequency distributions and mean annual water temperature, growth and mortality parameter estimates, as well as spawning pattern of Pellonula leonensis (Clupeidae) occurring in the Cross River (Nigeria) have been obtained. The estimated von Bertalanffy growth parameters are TL8 = 156 mm, and K = 0.81 - 0.96 year -1. Natural mortality ranges from M = 0.8 to 0.9 year-1. Spawning occurs during the whole year with a dominant peak in the dry season and a smaller peak early in the rainy season. A tentative scheme describing the spawning migrations of Pellonula leonensis is proposed.