• Journal of Fisheries and Marine Sciences Education
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• v.28 no.6
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• pp.1715-1723
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• 2016

The heat extracts of six kinds of medicinal herbs (Scutellaria baicalensis, Sophora flavescens, Citrus unshiu pericarpium, Lonicera japonica, Perilla frutescens, Benincasa hispida) were tested for non-specific immune response and disease resistance effects related with fish diseases on olive flounder, Paralichthys olivaceus. The preventive effects of 6 herbal mixtures against bacterial disease on cultured flounder were examined follow as feeding EP absorbed with the heat extract of six kinds of medicinal herbs. For feeding trial for 12th week, weight gain and serum analysis of fish fed various groups were not significant differences. Lysozyme activity of the 0.01 % treated group on 4th week showed significant increase. Histopathology of the administrated group for feeding period showed no particular signs of tissue degeneration. At 0.01% oral experimental group, relative percent survival (RPS) were only 50% to 75% for four weeks and eight weeks group by intraperitoneal injection with E. tarda. The results suggest that heat extracts of six kinds of medicinal herbs (0.01%) would be effective to enhance the nonspecific immunity and protective ability of olive flounder against fish pathogen.

• Journal of Aquaculture
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• v.19 no.2
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• pp.84-89
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• 2006

Effect of dietary inclusion of various sources of green tea on growth, immune system and challenging test of juvenile olive flounder Paralichthys olivaceus was investigated. Five experimental diets with triplicates were prepared: control, raw leaves, dry leaves, by-product and extract. Twenty five (an initial body weight of 52.5 g) were randomly distributed into 15 of 180 L flow-through tanks. Nutrient requirements of the experimental diets satisfied growth of juvenile olive flounder. The feeding trial lasted for 7 weeks. After 7-week feeding trial, blood were sampled from three randomly chosen fish for serum analysis of Iysozyme and bactericidal activity, and ten fish were infected with Edwardsiella tarda for challenging test from each tank. Weight gain (g/fish) of fish fed the diet containing extract and control diet was significantly higher than that of fish fed the other diets. Feed efficiency ratio for fish fed the diet containing extract and control diet was significantly higher than that for fish fed the diets containing raw leaves and by-product, but not significantly different from that for fish fed the diet containing dry leaves. Serum Iysozyme activity (units/ml) of fish fed the diets containing dry leaves and extract was significantly higher than that of fish fed the diets containing raw leaves and by-product, but not significantly different from that of fish fed the control diet. Serum bactericidal activity (${\times}10^6$ bacteria/ml) of fish fed the diet containing dry leaves and extract was significantly lower than that of fish fed the diets containing raw leaves, by-product and control diet in 3 hour. However, serum bactericidal activity of fish fed the diet containing extract was significantly lower than that of fish fed the other diets in 6 hour. And serum bacterial activity was low in fish fed the diets containing dry and raw leaves, by-product, and control in 6 hour in order. Accumulative mortality (%) of fish fed the control diet was low compared to that of fish fed the diets containing raw leaves and by-product, but high compared to that of fish fed the diets containing dry leaves and extract although no significant difference was found among treatments. In considering above results, dietary inclusion of extract and dry leaves of green tea seemed to be highly effective to improve immune system and endurance against E. tarda infection of juvenile olive flounder.