Call edition 2012
A new edition of the Prize of the Belgian Development Cooperation has been launched. This call is open until March 31st, 2011. You can read in the regulations whether you comply with the criteria for participation.
In a lot of developing countries fish represent an important and cheap source of proteins of good nourishing quality. The cichlids of the tilapia group, in particular, form part of an extensive pisciculture. Sarotherodon melanotheron, a West African lagoon species of this group, is subject to an intensive artisanal fishing from Ivory Coast to Nigeria.
The author has studied in an in-depth way the feeding habit and the reproduction of this species in the Bia river, affluent of the Abi lagoon (Ivory Coast) and the man-made Ayame Lake, which was created in 1959 on this river. The construction of the dam entailed, as is often the case, modifications of the physico-chemical parameters, of the plankton population, of the fish fauna and of some biological parameters of the fish population up – and downstream and in the lake itself. However, the study shows that S. melanotheron, a lagoon – and, therefore, a brackish water – species, has perfectly adapted itself to freshwater conditions, in particular those of the Ayamé Lake.
The phytoplankton and the zooplankton in the lake have been listed and the study shows that here S. melanotheron is essentially a plankton-eater. In the lake its favourite plant prey includes Asterionella and Aulacoseira (Bacillariophyceae) and its animal prey Bosmina (Cladocera). In the Bia river, both up- and downstream the dam, the Cyanophyceae, the Bacillariophyceae and the Chironomid larvae represent the larger part of the food sources, the latter being most important in volume.
This good adaptability turns S. melanotheron into a potential candidate for aquaculture and shows the appropriateness of studies regarding the growth performance of this species in the examined lake. As such, T. Koné’s work offers interesting perspectives for the development of food resources.
report by Prof. Dr. Jean-Jacques Symoens, Royal Academy for Overseas Sciences, Brussels, Belgium