Use of liposome-enriched rotifers to estimate the optimal dietary taurine concentration and evaluate the combined effect of taurine and vitamin C on first feeding larvae of California yellowtail (Seriola dorsalis)
摘要
Liposome-enriched rotifers were used to (1) determine the optimal concentrations of dietary taurine and (2) evaluate the effects and interactions of vitamin C and taurine on California yellowtail (Seriola dorsalis) larvae. A 15-day growth study (Trial 1) was conducted whereby Seriola larvae were fed liposome-enriched rotifers with six levels of dietary taurine. At the end of the trial, larval individual dry weights (mg larva−1) and whole-body taurine concentrations were significantly affected by dietary taurine concentrations. Based on the latter, we estimate the dietary taurine requirement for 2–17 days post hatch (dph) S. dorsalis to be 7.5 mg g−1 (95% CI = 6.6, 8.3). In a second study (Trial 2), we used liposomes to manipulate the concentrations of vitamin C and taurine in rotifers and then evaluated the effects and interactions of these nutrients on larval growth and oxidative stress. At the end of the 15-day feeding trial, larval condition factors decreased with increasing concentrations of dietary ascorbic acid provided by the enriched rotifers, but this trend was less pronounced when elevated taurine was also provided by the enriched rotifers. Larval whole-body malondialdehyde (MDAs) levels increased as larvae were fed rotifers that had been enriched with increasing concentrations of sodium ascorbate. Larvae had greater dry weights at the end of the trial when they received elevated levels of dietary taurine, regardless of the vitamin C concentrations provided. This study helps to identify optimal taurine concentrations in rotifers used to feed S. dorsalis and demonstrates the usefulness of liposome-enriched live feeds in studies of larval fish nutrition.