**Appendices and nomenclature**

which were all lower than the demands for lipid of aquatic animals [8]. For example, the recommended total lipid level in the diet for shrimp is in general higher than 6.5% [4]. Although external equipment could be used to settle the excessive part of biofloc, how to treat this deposit containing high content organic matter and

The efficiency for producing biofloc also needs to be elevated, if biofloc is used as a gradient of formulated feedstuff for replacement of fishmeal or soybean meal or used to feed to aquatic animals directly as a food with whole nutritional gradients usually contained in artificial feedstuff. The productivity of biofloc recent is not

Moreover, the improvement of biofloc palatability should be researched, which is important to the utilization of biofloc either eaten in situ or used as a food source [76]. Attractants or feeding promoting agents, like garlicin, betaine (trimethylglycine), trimethylamine oxide (TMAO), and s,s-dimethyl-β-propionic acid thetine (DMPT), could be taken into consideration as additives during development of biofloc in situ or preparing process for biofloc pellets. Thus, the effects of those agents on biofloc

Biofloc technology (BFT) supplies a novel solution for this issue without huge water exchange, even zero water exchange. In general, ammonia would be removed quickly within several hours in a BFT system. Moreover, because of the very high nutritional value for fish and shrimp, bioflocs, the by-product of BFT, could also be reused as a complemented food in situ or a gradient for feedstuff to replace expensive fishmeal, and biofloc also could be processed to formulate diet to feed fish and shrimp directly. However, some aspects with regard to the effective use of biofloc as a food source for fish and shrimp, such as high lipid content, productivity, and

This work is supported by the development funds of the Chinese central government to guide local science and technology (2017CT5013); the Sci-Tech program of Hunan province, China (2016NK2132); and the science and research program of

the Education Department of Hunan province, China (16C1085, 18B394).

The author also thanks the support from Collaborative Innovation Center (Hunan) for Efficient and Health Production of Fisheries, Hunan Engineering Research Center of Aquatic Organism Resources and Environmental Ecology, Hunan Engineering Research Center of Aquatic Organism Resources and Environmental Ecology, and Academician Workstation (Fisheries) of Hunan Province.

bacteria, part of which may be pathogens, was also a problem [39].

*Emerging Technologies, Environment and Research for Sustainable Aquaculture*

attraction to fish and shrimp should be studied in detail, respectively.

adequate for those uses in practical operations.

palatability, need to be further researched in detail.

The author declares no conflict of interest.

**Notes/thanks/other declarations**

**9. Conclusions**

**Acknowledgements**

**Conflict of interest**

**16**

