Journal of Agriculture & Life Sciences

Growth, Mortality Rates and Exploitation of Cichlids in Anthropological Coastal Zone in the North of Lake Tanganyika
Charles Niyonkuru, Pascal Isumbisho, Jacques Moreau

Abstract
Population parameters of main cichlids species from the anthropological coastal zone of the north of Lake Tanganyika were investigated using length-frequency data sampled tri-monthly (between February 2011 and September 2012) and analysed using the FiSAT software package. Extreme values estimated were L∞ = 35 cm (K= 0.2 year-1) for Boulengerochromis microlepis (Boulenger, 1899) and L∞ = 11 cm for Auronocranus dewindti and Callochromis pleurospilus (with K-values of 1.1 and 1 respectively). Extreme Φ’-values were 2.1 and 2.5 for C. pleurospilus and Limnotilapia dardennii respectively. Except for C. pleurospilus with M/K<2, M/K > 2 noticed for other species indicated that species have short longevity. The high natural mortality rate M recorded could be attributed to the prohibited fishing practices in use and to the environment degradation. Moreover, the Z/K>2.9 recorded for all species and the E- values calculated (E=F/Z) higher than 0.5, E50 and Emax (predicted maximum exploitation rate) indicated that fishes are overexploited.

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