The dominant bacteria of culture media of cladoceran Daphnia magna and copepod Acanthocyclops robustus

Bacteria and zooplankton are important components of the pelagic food web and major contributor to biogeochemical processes. In this research, the dominant bacteria associated with culture media of cladoceran (Daphnia magna) and copepod (Acanthocyclops robustus) fed on manure (cattle+poultry, 1:1 ratio in weight), vegetable(spinach + parsely + coriander, 1:1:1 ratio in weight), and algae (Scenedesmus quadricauda) were investigated. Results showed that D. magna fed on manure and vegetable had bacteria of Acinetobacter and with had Aeromonas bacterias while A. robustus fed on manure, vegetable and Scenedesmus dominated by bacteria of Neisseria, Enterobacteria andAlcaligenes, respectively. Effects of different diets were significant (P<0.05) on D. magna and A. robustus densities, bacterial density, BOD and COD of culture media. The highest bacteria density was obtained in D. magna culture medium fed on Scenedesmus (5×104 cell/ml) and the lowest on manure (9×103 cell/ml). In addition, at A. robustus cultures the highest and lowest bacteria were obtained 1.4×104 and 5.0×103 cell/ml, respectively. The maximum BOD was recorded on A. robustus fed on vegetable (90 mg/l) and minimum by D. magna fed on manure (28 mg/l). The maximum COD (313 mg/l) and minimum (43 mg/l) were recorded by A. robustus fed on vegetable and Scenedesmus, respectively. In addition, the parameters of BOD, COD and bacteria density had significant correlation with density of D. magna and A. robustus. As conclusion, findings of this research illustrated that type and density of bacteria were changed in different zooplankton culture media which depended on zooplankton species and their diets during cultivation.