Effects of different conditions on feeding biofloc of red swamp crayfish (Procambarus clarkii ) juveniles

Biofloc technology can maintain good water quality by adjusting the ratio of carbon to nitrogen in the aquaculture water, ensure the health of the cultured species, promote the multilevel utilization of microbial protein and save the cost of aqua-feed. We determined the suitable biofloc conditions for the red swamp crayfish (Procambarusclarkii) juveniles feeding by studying the feeding environment (aeration, no aeration and aquatic plants), feeding duration and biofloc concentration. The results show that 500–600 mg·L^–1 biofloc could meet the demand of juveniles, and the intestines of the fed juveniles were saturated after 4-hour feeding. With the same feeding duration, the juveniles from the group with aeration had the highest food intake, higher than the group with aquatic plants significantly (P<0.05), but no obvious difference was found in comparison with the non-aerated group (P>0.05). Comparing the fullness rank of intestine in each group, the group with aeration had more chyme after 4-hour feeding. Considering the culture conditions of biofloc, hydrochemical index as well as the feeding situation, it is feasible to apply biofloc technology to the culture of red swamp crayfish.