This study aims to evaluate the production performance of biofloc-based co-culture systems of Nile tilapia and redclaw crayfish with varying carbon–nitrogen ratios (C/N). The experiment was conducted for 80 days in plastic-lined ponds with dimensions of 1 x 1 x 0.6 m. Two biofloc systems with two C/N ratios (10 and 15), using molasses as the carbon source and a control system without molasses were compared. Mixed-sex Nile tilapia with an initial average body weight of 7.00 ± 0.25 g were stocked at a density of 30 fish m⁻². After 30 days of culture, redclaw crayfish with initial average body weight of 11.50 ± 0.55 g were added to the culture system at a density of 10 crayfish m⁻². There were no significant differences in total animal biomass or total weight gain between treatments (P > 0.05). The total feed and overall feed conversion ratio (FCR) differed significantly (P < 0.05) between the biofloc systems and the control. Total ammonia nitrogen (TAN), nitrite nitrogen (NO₂−N) and nitrate nitrogen (NO₃−N) concentrations in biofloc systems with a C/N ratio of 15 were generally lower than those of other treatments. Dissolved oxygen concentrations decreased with the increase in the culture period in (4.13–4.40 mg L⁻¹). Based on the results of this study, it can be concluded that an increase in the C/N ratio has positive effects on the feed utilization efficiency and water quality in biofloc-based tilapia–redclaw crayfish co-culture systems.

这项研究旨在评估基于生物絮凝物的尼罗罗非鱼和小爪小龙虾在碳氮比（C / N）不同的条件下的生产性能。该实验在大小为1 x 1 x 0.6 m的塑料衬砌池塘中进行了80天。比较了使用糖蜜作为碳源的两个具有两个C / N比（10和15）的生物絮凝系统和一个不含糖蜜的对照系统。初始平均体重为7.00±0.25 g的混交性尼罗罗非鱼以30鱼m ^-2的密度放养。培养30天后，将初始平均体重为11.50±0.55g的红爪小龙虾以10个小龙虾m ^-2的密度添加至养殖系统。处理之间动物总生物量或总体重增加无显着差异（P > 0.05）。在生物絮凝系统和对照之间，总饲料和总饲料转化率（FCR）有显着差异（P <0.05）。C / N为15的生物絮凝系统中的总氨氮（TAN），亚硝酸盐氮（NO ₂ -N）和硝酸盐氮（NO ₃ -N）浓度通常低于其他处理方法。随着培养时间的增加，溶解氧浓度降低（4.13–4.40 mg L ^-1）。根据这项研究的结果，可以得出结论，C / N比的提高对基于生物絮凝物的罗非鱼-小爪螯虾小龙虾共养系统的饲料利用效率和水质产生积极影响。