Orapuh Journal (Aug 2024)
Pre-fattening of fish Clarias gariepinus (Burchell, 1822) (Siluriformes, Clariidae) on local feed in an above-ground tank culture system in Kinshasa, Democratic Republic of the Congo
Abstract
Introduction Fish farming plays a major role in combating poverty and malnutrition by supplying poor populations with fish. In the Democratic Republic of Congo, Clarias gariepinus farming dates back to colonial times but remains underdeveloped due to difficulties in producing juveniles in captivity and the availability of good-quality local feed. This situation does not contribute effectively to the availability of animal proteins from fish. Purpose The aim of this study was to evaluate the growth of fry of the African catfish Clarias gariepinus Burchell, 1822, in a soilless rearing system to promote home fish production in the city of Kinshasa. Methods Rearing activities took place over 54 days between August and September 2021. The physicochemical parameters (pH, conductivity, turbidity, and temperature) of the water and the growth of the fry were monitored every ten days. A total of one hundred and fifty (150) Clarias gariepinus fry, with mean weights ranging from 1.00±0.35 g to 1.20±0.61 g and mean sizes ranging from 49.27±5.15 mm to 65.09±6.98 mm, were tested in an experimental setup using out-of-water tanks. The fry were divided into three batches and fed three times a day (8:00, 12:00, and 15:00) with three types of feed ration. Several zootechnical parameters were assessed to determine the growth of the reared fry. Results The pH, temperature, conductivity, and turbidity values recorded in the water of the tanks remained within the range required for the growth of Clarias gariepinus fry. The fry were well maintained in the experimental structures throughout the study period. The survival rate was between 86% (B1 and B3) and 88% (B2). Feed B1, composed largely of fish meal, had a greater influence on the weight (8.44±0.64 g) and linear growth (124.56±8.4 mm) of the fry than the control feed B3 (mean final weight = 5.35±0.7 g and mean final size = 105.75±5.13 mm) and feed B2 (mean final weight = 4.97±0.46 g and mean final size = 109.04±8.2 mm). Feed B1 also had a significant effect on the individual daily growth of fry (0.124 g/d) compared with feeds B2 (0.063 g/d) and B3 (0.069 g/d). The weight-total length relationship of the fry from the three batches confirms that the fish rearing system (concrete tanks) used in this study allowed the maintenance and development of the fry without negatively influencing the growth pattern of this fish species. Conclusion This study demonstrated the importance and effectiveness of the soilless culture system and the use of local feed for rearing Clarias gariepinus in the city of Kinshasa. The results of this study are of great importance for the development of fish farming in the Democratic Republic of Congo, using locally available feeds to increase the quantity of fish consumed in the country.
Keywords
