Overview of Length-Weight Relationship, Condition Factor and Size at First Maturity of Nile tilapia Oreochromis niloticus (L.) in Different Water Bodies of Ethiopia: A Review

Abstract

Length-weight relationship, condition factor and size at first maturity of Nile tilapia Oreochromis niloticus (L.) in different water bodies of Ethiopia have indicated that nearly isometric (b≈3) growth pattern. The Fulton condition factor (K) of O. niloticus was higher in Lake Chamo (2.35) and in Baro River (2.05) than in Gilgel Gibe Reservoir (1.87) and in Lake Langano (1.77). However, it was lowest in Lake Beseka (0.05). Size at first maturity (L₅₀) of O. niloticus was high (42.0 cm TL) for both sexes in Lake Chamo. However, declined in most water bodies of Ethiopia and also exhibits both sexual and seasonal variations. There was variation in size at first maturity with respect to sex in which males had larger size at first maturity than females. Generally, the length-weight relationship, condition factor and size at first maturity of O. niloticus was correlated with availability of food, feeding rate, gonad development, spawning period, water quality parameters can determine the growth rate and the condition of fish and therefore, proper management of this fish stock for conservation and sustainable fishery is critical.

Keywords: Condition Factor, Length-weight, Oreochromis niloticus, Size at first maturity, Water bodies of Ethiopia