Nutritional value of the amphipod Bemlos quadrimanus sp. grown in shrimp biofloc ponds as influenced by different carbon sources

Natural food items like amphipods in bioflocs have been shown to provide a nutrient-rich live feed for aquaculture species. In the present study, we aimed to identify the major species of amphipods in the biofloc technology shrimp ponds at Shrimp Village, Surat-Thani, Thailand, determine its nutritional values, and enrich the amphipods in the biofloc technology system (BFS). Breeder stage amphipods were cultured in BFS with different carbon sources; molasses, rice bran, and corn flour at a carbon: nitrogen (C:N) ratio of 16:1 for 4 weeks. The number and the growth of spawned juveniles, and the nutritional compositions of the amphipods enriched bioflocs were examined. We found that the major species of amphipods in bioflocs produced in the cultured shrimp ponds was Bemlos quadrimanus sp. Proximate analysis revealed that the juvenile stage B. quadrimanus had higher levels of protein and lipid contents than those in other stages. Moreover, their essential amino acid index (EAAI) and ratios of polyunsaturated fatty acid/saturated fatty acid (PUFA/SFA) and docosahexaenoic acid/eicosapentaenoic acid (DHA/EPA) were similar to those values in fishmeal. The bioflocs produced with corn flour enhanced the growth and increased the number of juvenile amphipods greater than in bioflocs produced with the other two carbon sources, and had the highest levels of crude protein and lipid. In summary, this study demonstrates that amphipod B. quadrimanus provide an important source of protein that shows potential to replace fishmeal in shrimp feed, and reveals the benefit of a culture of amphipods with BFS in the aquaculture industry.