克氏螯虾的生物学和生态养殖模式

生物絮凝技术可以通过在养殖水体中调节碳氮比而维持良好水质，促进养殖品种健康生长，产生的生物蛋白可实现蛋白的多级利用，节约经济成本。实验从摄食环境(曝气、无曝气、水草)、摄食时间以及生物絮凝质量浓度等角度，探讨了克氏原螯虾 (Procambarus clarkii) 幼虾摄食絮凝的适宜条件。结果显示，絮凝质量浓度为500~600 mg·L^–1可满足幼虾的摄食需求，并在摄食4 h之后幼虾肠道达饱和状态。相同摄食时间，絮凝曝气组幼虾摄食量最大，显著高于水草组(P<0.05)，但与无曝气组差异不显著(P>0.05)，比较幼虾肠道的充塞度，可见曝气组在摄食4 h后肠道食糜较多，肠道更为饱满，优于其他各组。综合生物絮凝培养条件、水化指标以及幼虾的摄食情况，认为生物絮凝技术应用到克氏原螯虾的养殖具有可行性。

Nitrogen removal techniques in aquaculture for a sustainable production

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.