Some aspects of reproduction and feeding habits of Nile tilapia (Oreochromis niloticus) in three dams in Uasin Gishu County, Kenya

Abstract

Knowledge of the fisheries status of dams within Uasin Gishu County was needed prior to the government's plan to introduce fish and fisheries in the area. The dams were constructed in the 1950s and stocked with tilapia for local consumption, recrea‐ tion and control of macrophytes. The Nile tilapia (Oreochromis niloticus) was selected for the present study due to its establishment success and popularity in the Kenyan market. Water samples were collected at subsurface levels for phytoplankton analy‐ sis and compared with the phytoplankton found in the stomachs of O. niloticus, re‐ vealing the food preference of the fish in a natural environment. Fish samples were collected with gillnets and beach seines. The results of the present study identi‐ fied the most important food items for the fish were Chlorophyceae (green algae), Bacillariophyceae (diatoms) and Cyanophyceae (blue‐green algae). The fish exhibited a relative condition factor of about 1.00, indicating their robustness or well‐being in the dams. The LM50 was reached at 18–20 cm class interval, which coincides with the most critical breeding biomass needing some kind of protection for sustainable management of the fishery