Effects of dietary supplementation with freeze-dried powder of Ampithoe sp on the growth performance, energy metabolism, and ammonia-nitrogen tolerance of the Pacific white shrimp, Litopenaeus vannamei

This study evaluated the influence of dietary supplementation with freeze-dried powder of Ampithoe sp. (FDPA) on the growth, energy metabolism, and resistance to ammonia-nitrogen stress in Litopenaeus vannamei. There were four treatment groups: a 0% group (no FDPA addition), a 33% group, a 66% group (33% and 66% of the shrimp diet, respectively, replaced with FDPA), and a 100% group (only FDPA). The results of this study suggested a positive effect of FDPA supplementation on shrimp survival: the supplemented groups had significantly higher survival than the 0% group (p<0.05). The body length, body weight, and specific growth rate (SGR) of the 33% group were higher than those of the other groups and were significantly higher than that of the 100% group (p<0.05). FDPA feeding had a negative effect on carbohydrate metabolism pathways and energy consumption due to decreases in pyruvate kinase (PK), phosphofructokinase (PFK), succinate dehydrogenase (SDH), lactic dehydrogenase (LDH), and respiratory electron transport system (ETS) activity in shrimp fed FDPA during the culture period. The shrimp in the 33% group exhibited good resistance to ammonia-nitrogen stress. Additionally, the glycolysis pathway and energy consumption of shrimp in the 33% group were enhanced during the ammonia-nitrogen stress period. Consequently, it was inferred that FDPA supplementation could improve the resistance of shrimp to ammonia-nitrogen stress (in the 33% group), which might be related to the effects of the supplement on energy metabolism pathways, particularly in terms of enhancing glycolysis to provide sufficient energy for the stress response.