DIETARY RIBOFLAVIN LEVELS ON THE MITOCHONDRIAL BIOGENESIS AND FUNCTION OF ORIENTAL RIVER PRAWN (MACROBRACHIUM NIPPONENSE)

This study investigates the effects of different dietary riboflavin levels on the mitochondrial biogenesis and function of oriental river prawn (Macrobrachium nipponense) average initial weight: (0.67±0.01) g). Three semi-purified diets with different riboflavin concentrations (3.91, 169.61, and 326.66 mg/kg) were tested on prawns kept in an indoor recirculating water system for 10 weeks. The three treatments were designated as the deficient, optimal, and over-dosed groups, respectively. The results showed that in the 169.61 mg/kg riboflavin group, feed efficiency, hepatopancreatic Na⁺-K⁺-ATPase and mitochondrial complex III activities, cytochrome C content, and Cytochrome C oxidase-Ⅱ (cox-Ⅱ) transcription were all significantly higher (P<0.05) than those in the 3.91 and 326.66 mg/kg groups. The hepatopancreatic ATP content and transcriptions of cox-Ⅰ and ATP synthase in the 169.61 mg/kg riboflavin group were all significantly higher than those of the 3.91 mg/kg group (P<0.05), but showed no significant difference with the 326.66 mg/kg group (P>0.05). However, the average daily gain, hepatopancreatic succinate dehydrogenase activity in the 169.61 mg/kg riboflavin group was significantly higher than that in the 326.66 mg/kg group (P<0.05), with no significant difference compared to the 3.91 mg/kg group (P>0.05). Additionally, the 326.66 mg/kg group showed significantly higher citrate synthase activity (P<0.05) than the other groups and a higher mitochondrial complex V activity than the 3.91 mg/kg group (P<0.05). Furthermore, the AMP/ATP ratio in the 3.91 mg/kg group was significantly higher compared with the other groups (P<0.05). These findings suggest that dietary inclusion of 169.61 mg/kg riboflavin can promote mitochondrial biogenesis and function in M. nipponense.