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Objectif: Deux souches du tilapia du Nil Oreochromis niloticus, trouvées dans la région du Sud-Kivu en RD Congo, dont une récemment prélevée du milieu naturel (souche Lac Kivu) et une autre ayant un long passé de domestication (souche Nyakabera) ont été comparées en station de pisciculture en vue de déterminer laquelle avait les meilleures performances de croissance.Méthodologie et résultats: Après 183 jours de maintien dans des conditions zootechniques similaires, les poissons de taille marchande dans les deux souches étaient dans une bonne condition (K ˃ 1), toutefois avec une supériorité (p˂0,05) de la souche Lac Kivu (K=1,80±0,02) par rapport à la souche Nyakabera (K=1,71±0,01). Les poissons pesant 200 g et plus représentaient 85% de la récolte chez la souche Lac Kivu contre 70% chez la souche Nyakabera. Le poids moyen final des géniteurs initiaux était de 285,4±3,6g et 199,5±3,1 g, respectivement pour la souche Lac Kivu et la souche Nyakabera. Le gain de poids individuel était de 278,0±4,9 g et 187,1±5,1 g, la croissance journalière individuelle de 1,52±0,16 g/jour et 1,02±0,19 g/jour, le taux de croissance spécifique de 1,99±0,03 %/jour et 1,52±0,03 %/jour, respectivement pour la souche Lac Kivu et la souche Nyakabera. Pour ces quatre derniers paramètres, les différences entre les deux souches étaient significatives (p˂0,05) en faveur de la souche Lac Kivu qui a ainsi manifesté les meilleures performances de croissance.Conclusion et application des résultats: Les performances de croissance des souches Lac Kivu et Nyakabera d’Oreochromis niloticus sont liées à leur origine ainsi que leur histoire de domestications respectives. La contre-performance de la souche Nyakabera serait liée aux effets pervers du faible effectif du stock de géniteurs à partir duquel elle a été fondée à l’origine. Les pisciculteurs du Sud-Kivu et des régions avoisinantes peuvent désormais utiliser préférentiellement les alevins produits à partir de géniteurs du tilapia du Nil du lac Kivu pour améliorer les rendements de leurs exploitations.Mots-clés: facteur de condition, lac Kivu, conditions zootechniques, taux de croissance spécifique, taux de survieEnglish AbstractObjective: Two strains of Nile tilapia Oreochromis niloticus, found in the South Kivu region of DR Congo, one recently taken from the natural environment (Lac Kivu strain) and another with a long history of domestication (Nyakabera strain) were compared in fish farm to determine which had the best growth performance.Methodology and results: After 183 days of maintenance in similar zootechnical conditions, the commercial size fish in both strains were in good condition (K ˃ 1), but with a superiority (p˂0.05) of the Lac Kivu strain (K = 1.80±0.02) relative to the Nyakabera strain (K = 1.71±0.01). At the harvest, fish weighing 200 g or more accounted for 85% in the Lac Kivu strain compared to 70% in the Nyakabera strain. The final average weight of the starting broodfish was 285.4±3.6 g and 199.5±3.1 g for the Lac Kivu strain and the Nyakabera strain, respectively. The individual weight gain, individual daily growth, and specific growth rate were respectively 278.0±4.9 g; 1.52±0.16 g/day and 1.99±0.03%/day for Lac Kivu strain and 187.1±5.1 g; 1.02±0.19 g/day and 1.52±0.03%/day for the Nyakabera strain. For these last four parameters, the differences between the two strains were significant (p˂0.05) in favor of the Lac Kivu strain, which thus showed the best growth performance.Conclusion and application of results: The growth performance of the Lac Kivu and Nyakabera strains of Oreochromis niloticus are related to their respective origin and domestication history. The Under performance of the Nyakabera strain would be related to the adverse effects of the low stock size of the parent stock from which it was originally based. Fish farmers in South Kivu and neighboring regions can now preferentially use fry produced from Lake Kivu Nile tilapia broodstock to improve the yields of their farms.Keywords: condition factor, Lake Kivu, zootechnical conditions, specific growth rate, survival rate

The fisheries of Lake Tanganyika play an important role in food security in Central and Eastern Africa. Conservation of these valuable fish stocks will benefit from documenting the ideas, opinions and observations of stakeholders. Knowledge of the perceptions and an understanding of the concerns and struggles of stakeholders of these fisheries can provide policy-makers with recommendations for more suitable fisheries management. We did 1018 interviews with stakeholders, in one close-ended and three semi-open ended surveys. Factor analysis revealed seven clusters of opinions. Linear-mixed effects models identified common grounds and differences in opinions between groups of stakeholders about strategies in fisheries management. Stakeholders of the fisheries indicated challenges due to weather or climate variability, a noticeable decrease in fish abundance and size, and an increase in the price of fish. Fishermen experienced a lack of safety on the lake, including aggression and dangerous weather conditions, and hardly had access to safety gear and infrastructure. Landing site officials, state employees who monitor the beaches, mentioned capture of juveniles and declining catch-rates as the biggest threats to the fisheries. None of the groups of stakeholders attributed the problems in the fisheries to overfishing or overpopulation. We found similarities in opinions over a wide range of stakeholder groups, with many stakeholders asking for better and fair enforcement of existing legislation. State employees were more positive than the other groups towards creating more strict regulation of the fisheries. The results presented offer focuspoints for policy-makers to improve the management of the Lake Tanganyika pelagic fisheries.