Abstract
The effect of ascorbic acid (AsA) on schooling behaviors of ayu Plecoglossus altivelis was examined using L-ascorbyl-2-phosphate-Mg as a vitamin C source. The trial using 10g size (250 fish in each tank, duplicate tanks per dietary treatment) was conducted for 36 days with testdiets containing different concentrations of AsA (0, 18, 150, and 541mg/kg diet). Schooling behavior wasobserved using the video camera system with 10 fish from each treatment after the trial.
Ayu fed a AsA-free diet did not form any schooling. Aggressive behavior, spontaneous activity, and distance to the nearest neighbors were greater in fish fed AsA supplemented diets than those fed a AsA-free diet. Particularly, fish fed a diet with 150mg AsA/kg showed the greatest value of those behavior parameters. During 36-day feeding trial survival was more than 90% and vitamin C deficiency signs were not observed in any treatment groups. The highest accumulations of AsA in both liver and brain at the end of feeding trial were found in fish fed a diet with 541mg AsA/kg.
Since the complex behavior such as schooling, being governed by tahe central nervous system, was affected by AsA intake in the present study, we suggest that vitamin C might actas the modulator of neurotransmitter in fish.
