Fig. 1

Microbial colonies isolated from water and waste samples from Tilapia and Clarias RAS and enumerated on 0.1 % Tryptic soya agar (TSA) complemented with cycloheximide (100 µL mL^− 1) for enumeration of the general bacterial flora; 0.5 % malt extract agar (MA) for enumeration of the general fungal flora; and on King Agar B (KB) with cycloheximide (100 µg mL^− 1) for enumeration of fluorescent pseudomonads. Letters above the bars indicate the significant differences between the treatments