Effects of different levels of water exchange on the growth performance, survival and haematology indices of Clarias gariepinus

Abstract

Water determines the success or failure of an aquaculture operation to a greater extent. During dry season and regions with low accessibility to water, productivity tends to be reduced. This study determined the effect of different levels of water exchange required for producing African mud catfish. One hundred and eighty Clarias gariepinus (2.69±0.94 g fish^-1 ) were randomly distributed at 15 fish per tank into four treatments with three replicates. Each treatment was named according to the daily water level renewal, namely; T₀ (Complete renewal), T₁ (Quarter renewal), T₂ (Half renewal) and lastly, T₃ (three-quarters renewal). The experiment lasted eight weeks, twice daily feeding with commercial feed at 5% body weight. No significant differences recorded in the water quality parameters of all the treatments. However, T₂ had the highest final weight of 52.06±1.01g and weight gained 6.73±3.96 g. T₂ retained the highest specific growth rate (6.01±1.42 g day^-1 ). The most increased FCR was recorded in T₀ (0.64±0.30). All the treatments had high survival at the end of the experiment, with the highest value (90-100 %). The result showed that PCV and haemoglobin were significantly (P<0.05) higher in T₂ (31.00±0.0 % and 10.30±0.0 g/dl) and T₁ (31.00±1.41 % and 10.50±0.7 g/dl). Red blood cell was significantly higher in T₀ (2.15±0.07). This study showed that the daily water exchange to half the water level volume produced the best result in terms of growth performance. This is optimum and affordable for growth and health of Clarias gariepinus fingerlings production.