Centre Universitaire de Recherche et de Pédagogie Appliqués aux Sciences, laboratoire de Nutrition-Phytochimie, Environnement et Ecologie Appliqués aux Sciences, Institut de Pédagogie Appliqué, Université du , BP: 5223 Bujumbura, Burun, Burundi
Parameters of the weight-length relationship and the condition factor are very important in the knowledge of several aspects of biology and in the management of fisheries. Unfortunately, there are few studies relating to the ichthyofauna of Lake Tanganyika in general and cichlids in particular. This study was conducted with the aim of contributing to enrich the existing database and the rational management of the lake. Total lengths and weights were obtained based on T. unimaculatum and O. niloticus fish samples collected over 8 months (January to August 2021). The correlations between the length and the weight of the specimens are very strong with coefficients of determination ranging from 0.95 to 0.99. In both stations, positive allometry was recorded in T. unimaculatum (b>3) while isometric growth was recorded in O. niloticus. Mean K is greater than 1 in O. niloticus while mean K <1 in T. unimaculatum. In the latter species, the average K varies significantly depending on the sites (p<0.5) whereas the variation in the average K is not significant in the two sites in O. niloiticus (p>0.). This shows that the two species of cichlid fish adapt differently to the two stations with different environmental characteristics: O. niloticus seems indifferent to the degree of pollution while T. unimaculatum displays an average K in a station known to be less polluted compared to the ‘other.