author(s)
Jorge M Castro, Germán M Castro, Fernando S Dávila and Andrés Elías C Castro

abstract
The main goal of this study was to know if heterotrophic bacteria obtained from Biofloc Tilapia system can be used as food source to cladocerans organism. This study was made with Moina macrocopa, which was cultured by triplicate in 20 L plastic beakers at 19°, 23° and 25 °C temperature, for 60 days at Live Food Production Laboratory of Universidad Autónoma Metropolitan Xochimilco, during May to June of 2017. The bacteria source was obtained from culture medium of Biofloc system with tilapia organisms, which was screened through 20 µm PVC sieve. Every third day a sample of 500 mL was taken from each culture medium and all organisms were counted. The maximum density was obtained at 23°±1°C with 85,552±255 org, whereas, lower density was found at 19°±1°C with 9,921±219 org. The ANOVA analysis showed significant differences (P<0.001) between experimental treatments. Obtained reproduction rates values were r=0.73 to 0.139; Ro=22 to 192 org. per female and Tc=39.31 to 42.23 days. Tendency curves show a polynomic second grade curves with R2 up to 0.90 of correlation value. Heterotrophic bacteria can be used as food to maintain cladocerans low-density culture or in mixed diets with microalgae.