1. (1) The biology, especially the food and feeding habits of the cichlid fish Tilapia melanotheron Rüppel 1852 in a small West African lagoon is analysed. The food consists of bottom mud, which has an organic content of 30% and a calorific content of 1.2 Kcal/g. The daily food intake per fish weighing 20 g (fresh weight) was estimated to be 1.5 g (dry weight) and the calorific assimilation a minimum of 900 cal/day. Reproduction seemed to occur throughout the whole year, parasitism was low due to varying salinity of the lagoon. 2. (2) The small artisanal lagoon fishery produces about 150 kg fish per ha per year, with a fish catch per unit of effort of up to 1 kg/man-h. The fishing intensity was 70 man-h/km 2. Gill nets, seines and cast nets are used and over 90% of the catch consisted of T. melanotheron. 3. (3) Three alternative methods to increase the quantity of the fish caught in the lagoon are briefly discussed: (a) setting up of an “acadja” fishery; (b) stocking with juvenile T. melanotheron; (c) stocking with Mugil spp. fry ( Tilapia/Mugil polyculture). The availability of Mugil spp. fry along the coast makes the latter alternative look like the most promising one, being the cheapest and easiest to implement on a large scale.