The e¡ects of the dietary medicinal herbs Massa medicata, Crataegi fructus (Cf), Artemisia capillaries, Cnidium o⁄cinale and their mixture (HM), on growth and resistance againstVibrio anguillarum were examined using larval red sea bream, Pagrus major. The methanol extracts of Cf and HM inhibited the proliferation of seven infectious bacterial strains including the genera Aeromonas, Edwasiella, Photobavterium, Pseudomonas and Vibrio. Rotifers enriched with emulsi¢ed bonito oil containing extracts of Cf and HM lowered the bacterial counts in their body on TCBS medium for the genus Vibrio in comparison with rotifers enriched by emulsi¢ed bonito oil alone. Although statistically not signi¢cant, larvae fed rotifer forti¢ed with Cf from 3 to 20 days after hatching showed the best growth and ¢nal body weight followed by those given rotifer with HM and control enrichment. However, ¢nal body length of larvae fed rotifer with Cf was signi¢cantly larger than larvae fed on rotifers enriched with other herb extracts. After a challenge test withV. anguillarum, survival of larvae fed rotifer with Cf and HM was signi¢cantly higher than for the control treatment. These results revealed that Cf and HM in rotifer is useful to promote growth and resistance against V. anguillarum in red sea bream larvae, providing a new technology for mass production of disease-resistant fry and ¢ngerlings.

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This study was carried out to investigate whether expensive enzyme-treated fish meal (EFM) can be partially replaced by soybean meal (SM) or enzyme-treated SM (ESM) without compromising the growth of captiveraised Pacific bluefin tuna (PBT) juveniles. Five fish diets were tested: EFM (control) and EFM in which 10 or 20% of the EFM was replaced with either ESM or SM (ESM 10 , ESM 20 , SM 10 and SM 20 , respectively). The respective diets were provided to 28-day-old PBT juveniles (mean body weight approx. 0.38 g) stocked randomly in 15-m 3 tanks (276 juveniles per tank; two tanks per treatment) for 12 days. The final mean body weight of PBT juveniles on diets EFM, SM 10 , and SM 20 was significantly higher than that of juveniles on diet ESM 20 . Although daily feeding rate was significantly higher in the ESM and SM groups, feed efficiency (FE) was significantly higher in the EFM group; there was no significant difference between juveniles fed diets EFM and SM 10 . Protein and phosphorus retention efficiency were significantly lower in the ESM 20 , and ESM 20 and EFM groups, respectively. Phosphorus discharge was significantly lower in the SM groups. The results demonstrate that 10% SM (11% EFM replacement) can be included in EFM without compromising the growth performance of PBT juveniles.