Evaluation of Tilapia spp. in Lake Manzalah as pond fishes

Abstract

       Lake Manzalah, the largest brackish delta lake of Egypt, is subject to large land reclamation projects which have diminished its area. There is now an intention to convert the peryphery of this lake, which extends for about 300 km, into fish farms to compensate for the decrease in fish production. This study was made on Tilapia aurea and T. nilotica in winter 1980 and spring 1981, to evaluate their potential as pond fishes in the proposed fish farms.

      Age analysis was carried out to show difference in growth for the fish in two seasons and for both sexes.

      Sample standard deviation and the population standard deviation were calculated for length and weight in two species. Length-weight equations and the differential rate of increase in fish weight per unit legth were calculated, together with the survival rate of the fish.

      From this information, recommendations for the successful culture of T. aurea and T. nilotica in fish farms constructed on the periphery of Lake Manzalah are given.