Effect of organic and inorganic fertilisers on natural food composition and performance of African catfish fry produced under artificial propagation

In recent times, the African catfish, Clarias gariepinus has gained popularity in the aquaculture sector of Tanzania. However, many aquaculture farmers face the challenge of unreliable supply of seed due to difficulties of reproducing in captivity and high larvae mortality. This study was conducted to determine the effect of organic and inorganic fertilizers on natural food composition and performance of African catfish fry produced under artificial propagation. A completely randomized and factorial experimental design were adopted with three replication for a one week and two months period of time, respectively. Plankton abundance and diversity, growth performance and survival rate of African catfish fry were determined. One way and two way analysis of variance (ANOVA) were used to determine differences between treatments (p<0.05). Post-hoc analysis was done where significant differences existed between treatments using Tukey’s Test. Results indicated that phytoplankton abundance and diversity were significantly higher (p<0.05) in di-ammonium phosphate (DAP) fertilizer applied tanks compared to chicken manure and no fertilizer. Zooplankton diversity was also higher in tanks applied with chicken manure in comparison with other treatments. Growth performance was higher in fertilized tanks compared to unfertilized tanks at low stocking density (5fry/m2). There was no significant difference (p>0.05) in fry survival rates between chicken manure and DAP fertilized treatments across stocking densities. Water quality parameters were within the optimum ranges.