Shunsuke Koshio

Growth, stress tolerance and non-specific immune response of Japanese flounder Paralichthys olivaceus to probiotics in a closed recirculating system

Effects of probiotics on growth, stress tolerance and non-specific immune response in Japanese flounder Paralichthys olivaceus were evaluated in a closed recirculating system. Survival and growth of flounder treated by supplying commercial probiotics either in the diet (the probiotic diet group), or into the rearing water (the water supply group), were higher compared to the untreated group (the control group). Water quality parameters, pH, NH4−N, NO2−N and PO4−P showed lower concentration in the probiotic diet group compared with the control group and the supply group. Plasma lysozyme activity in the probiotic diet group and the water supply group was significantly higher (P<0.05) than that in the control group. In heat shock stress tests, flounder in the probiotics-treated groups showed greater heat tolerance (measured by 50% lethal time, LT50) than the control group. Pathogen challenge tests with Vibrio anguillarum (2×107 c.f.u./mL) resulted in significantly higher survival in the probiotics-treated groups than the control group. Results indicated that probiotics supplied in the rearing water and the diet of fish enhanced the stress tolerance and the non-specific immune system of Japanese flounder, providing them a higher resistance against stress conditions and pathogens.

Arginine requirement of juvenile Japanese flounder Paralichthys olivaceus estimated by growth and biochemical parameters

Abstract Growth performance and different biochemical parameters were evaluated to estimate the arginine requirement of juvenile Japanese flounder, by feeding purified diets containing 50% crude protein from casein, gelatin and l -crystalline amino acids (CAA). CAA were supplemented to correspond to the amino acid pattern found in the whole body protein of the Japanese flounder except for arginine. Diets with six graded levels of arginine (from 1.25% to 3.25% of diet) were fed to triplicate groups of the juveniles (1.85±0.05 g) twice a day for 40 days at 5% of body weight. To prevent leaching losses, CAA were pre-coated with carboxymethylcelloluse (CMC) and diets were further bound by both CMC and k-carrageenan. After the feeding trial, plasma-free arginine and urea levels, excreted ammonia–N and urea–N in the water and liver arginase activity were analyzed to compare the result of the growth studies. Percent survival, specific growth rate, feed conversion efficiency and apparent protein retention were significantly ( P

Diet development and evaluation for juvenile abalone, Haliotis asinina: animal and plant protein sources

Growth studies were conducted to determine the suitability of animal and plant protein sources in the diet of abalone, Haliotis asinina. Juvenile abalone with mean initial weight and shell length of 0.69±0.04 g and 11.4±0.35 mm, respectively, were fed practical diets for 84 days at a temperature range of 28–31 °C. The practical diets contained 27% crude protein from various sources such as fish meal (FM), shrimp meal (SM), defatted soybean meal (DSM), and Spirulina sp. (SP). A formulated diet (diet 1) served as the control. The diets were fed to abalone at 2–5% body weight once daily at 1600 h. Weight gain (WG), increase in shell length (SL), specific growth rate (SGR), protein efficiency ratio (PER) and feed conversion ratio (FCR) were evaluated. Highest weight gain (WG: 454%) was attained with abalone fed diet 2 with protein sources coming from a combination of FM, SM, and DSM. This value was, however, not significantly different (P<0.05) from those fed diets 4 and 1 (Control diet) with protein sources coming from FM, SM, SP and FM, DSM, SM, respectively. Abalone fed diet 3, which used both plant protein sources, DSM and SP, showed significantly lower WG (327%). Survival was generally high ranging from 85% to 100% for all treatments. The SGR showed the same trend as the percent weight gain. The FCR and PER obtained, however, were not significantly different for all treatments. The amino acid profile of diets 1, 2, and 4 simulated that of the abalone protein, which could have been a contributing factor to the higher growth rate of abalone fed these diets. Diet 3, which contained only plant protein sources, showed relatively lower methionine values compared with the abalone muscle tissue. Although abalone are considered herbivorous animals, results of this study indicate that a combination of dietary plant and animal protein sources was necessary to attain the best growth rate.

Effects of feeding rate on growth performance of white sturgeon (Acipenser transmontanus) larvae

Four 1-week trials were conducted to determine the effects of feeding rates on growth performance and body proximate composition of white sturgeon larvae during each of the first 4 weeks after initiation of feeding. Feeding rates (% body weight day(-1)) were 10, 20, 30, 40, 50, and 60 for trial I; 5, 10, 15, 20, 25, and 30 for trial II; and 2.5, 5.0, 7.5, 10.5, 12.5, and 15.0 for trials III and TV Four tanks with 200 larvae each were randomly assigned to each of the six feeding rates. Average initial body weights of the larvae were 49, 94, 180, and 366 mg, respectively, for trials I-IV. The larvae were kept at 19-20 degreesC in circular tanks and fed continuously one of two commercial salmonid soft-moist feeds using automatic feeders. Proximate composition (%) of the feeds for trials I-III and IV were 13.9 and 14.9 moisture, 52.5 and 50.0 crude protein, 10.3 and 12.9 crude fat, and 8.1 and 8.7 ash, respectively. Except mortality in trial I, gain per food fed in trial III, and body ash in all trials, growth performance and body composition were significantly (Pl0.05) affected by all feeding rates. Broken line analysis on specific growth rates indicated the optimum feeding rates of white sturgeon larvae to be 26%, 13%, 11%, and 6% body weight day-respectively, for weeks 1, 2, 3, and 4 after initiation of feeding

The effect of dietary protein content on growth, digestion efficiency and nitrogen excretion of juvenile kuruma prawns, Penaeus japonicus.

Abstract The effect of dietary protein contents on growth, digestion efficiency and ammonia and urea excretion of juvenile kuruma prawns, Penaeus japonicus , was investigated. Isocaloric, crab-protein-based, dry diets containing five protein contents (21 to 61%) were formulated and fed to prawns (initial mean wet wt 0.4 g) at a ration level of 6% body weight per day for 30 days. At the end of the trial, intermolt-staged prawns (0.5 to 2.0 g wet weight) were used for determination of digestion efficiencies for dry matter and protein, and ammonia and urea excretion rates. Weight gain, specific growth rates (SGR) and feed conversion efficiency (FCE) values for prawns fed diets containing 21 and 31.4% protein were significantly lower than those for prawns fed diets containing higher protein contents. There was no significant difference in weight gain, SGR and FCE values among prawns fed the 41.6, 50.3, and 60.7% protein diets. Digestion efficiencies for dry matter and protein ranged from 73 to 77% and 93 to 96%, respectively. After a 1-h feeding period, cumulative ammonia excretion over a subsequent 5-h period increased with increasing dietary protein content, and ammonia excretion reached a peak within the first 3-h period in all treatment groups. In contrast, ammonia excretion rates of prawns initially fed on diets with different protein contents then starved for 24 h, were constant at about 10 μ g/g h −1 , indicating that a 24-h starvation period eliminated differences in ammonia excretion rates due to variation in dietary protein content. Urea excretion rates were much lower than ammonia excretion rates in this species. Results indicated that 42% dietary protein sustained maximum growth of kuruma prawns under the conditions employed in this study, and that there was a positive correlation between SGR and ammonia excretion for juvenile P. japonicus .

Interaction effects of dietary supplementation of heat-killed Lactobacillus plantarum and β-glucan on growth performance, digestibility and immune response of juvenile red sea bream, Pagrus major.

Both heat-killed Lactobacillus plantarum (HK-LP) and β-glucan (BG) play important roles in growth performance, feed utilization and health status of fish. Therefore, a feeding trial was conducted to determine the interactive effects of dietary HK-LP and BG on growth performance, digestibility, oxidative status and immune response of red sea bream for 56 days. A significant interaction was found between HK-LP and BG on final body weight, total plasma protein, glucose, serum bactericidal activity (BA), total serum protein, serum alternative complement pathway (ACP) activity, protein and dry matter digestibility coefficients (P < 0.05). In addition, body weight gain, specific growth rate, feed intake, protein efficiency ratio as well as serum lysozyme activity, ACP activity and mucus secretion were significantly affected by either HK-LP or BG (P < 0.05). Further, feeding 0.025% HK-LP combined with 0.1% BG significantly increased serum peroxidase activity compared with the other groups (P < 0.05). However, protein body content, somatic parameters, total bilirubin, blood urea nitrogen, glutamyl oxaloacetic transaminase (GOT), glutamic-pyruvate transaminase (GPT), triglycerides and mucus BA were not significantly altered by supplementations (P > 0.05). Interestingly, fish fed with both HK-LP at (0.025 and 0.1%) in combination with BG at (0 and 0.1%) showed higher oxidative stress resistance. Under the experimental conditions, dietary HK-LP and BG had a significant interaction on enhancing the growth, digestibility and immune responses of red sea bream.

Influence of different dietary amino acid patterns on growth and body composition of juvenile Japanese flounder, Paralichthys olivaceus

A feeding trial using five semi-purified diets (50% crude protein) was conducted to investigate the effects of different dietary amino acid patterns on growth and body composition of juvenile Japanese flounder. The control diet contained casein and gelatin as intact protein sources and four other diets contained 30% casein–gelatin (2:1, w/w) and 20% crystalline amino acids (CAA). CAA were added to the diets to simulate the amino acid pattern found in red sea bream egg protein (REP), Japanese flounder larvae whole body protein (FLP), Japanese flounder juvenile whole body protein (FJP), and brown fish meal protein (BFP), respectively. The test diets were fed to triplicate groups of juveniles (2.75±0.05 g) twice a day for 40 days to evaluate weight gain, survival, feed conversion efficiency (FCE), protein efficiency ratio (PER), and apparent protein utilization (APU). The apparent retention of total dietary amino acids in the whole body and A/E ratios of the whole body were also evaluated. The highest weight gain was observed in fish fed the diet containing the dietary amino acid pattern of BFP followed by fish fed the control, FJP, FLP and the REP diets. Percent survival, FCE, PER and APU were also significantly (P<0.05) affected by the amino acid pattern in the diets, indicating the highest value in fish fed the BFP diet. Except for a few amino acids, the amino acid composition of the whole body did not show marked differences with different dietary amino acid pattern. Results suggest that BFP could be more suitable as a reference amino acid pattern in the diet of juvenile Japanese flounder compared to the amino acid pattern of FLP, FJP or REP.

Lipid metabolism of the prawn Penaeus japonicus during maturation: Variation in lipid profiles of the ovary and hepatopancreas

1. 1. Lipids (TL) were extracted from the ovary and hepatopancreas of prawns, Penaeus japonicus, with varying degrees of ovarian maturation and were analysed for lipid class composition, fatty acid composition of triglycerides (TG) and phosphatidylcholine (PC), and possible fatty acid combination of PC and phosphatidylethanolamine (PE). 2. 2. The concentrations (% of fresh wt) and quantities (mg/prawn) of ovarian TL increased slightly and drastically, respectively, with increasing maturity in terms of gonadosomatic index (GSI). TG, PC and PE were the major lipid classes responsible for increases in the quantity of ovarian TL during maturation. 3. 3. In the ovary and hepatopancreas, as ovarian maturation proceeded, TG showed increases in the proportion of monoene fatty acids such as 16:1 and 18:1, whereas PC exhibited increases in the proportion of highly unsaturated fatty acids such as 20:5ω3 and 22:6ω3 with a concomitant decrease in 16:0 and 16:1. 4. 4. No marked variation was found in the proportion of the possible fatty acid combinations, in terms of carbon numbers, of both ovarian PC and PE during maturation.

Lipid Nutrition of the Spiny Lobster Panulirus Japonicus (Decapoda, Palinuridae): a Review

The nutritional research on crustaceans such as the American lobster Homarus americanus and the prawn Penaeus japonicus has been reviewed by several workers. However, nutritional studies on Palinuridae are very scarce, particularly on the larval stages that are difficult to rear under artificial conditions. In the present paper, lipid nutrition of the spiny lobster, Panulirus japonicus, is reviewed and compared with that of American lobsters or prawns. Crustaceans have been shown to require lipids such as essential fatty acids, phospholipids and sterols. We investigated tissue uptake of [14C] n-3 highly unsaturated fatty acids for the spiny lobster using [14C] labeled eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). The results demonstrated that both [14C] EPA and [14C] DHA in the muscle and hepatopancreas were incorporated at higher levels (76 to 91% of total radioactive lipids) in phospholipids such as phosphatidylcholine and phosphatidylinositol than in neutral lipids (9 to 24% of total radioactive lipids). It was found that the ability for the bioconversion of EPA and DHA to other fatty acids is probably lacking in spiny lobsters. These results agree with those of studies on other Crustacea.

Effects of Partial Substitution of Fish Meal by Soybean Meal with or without Heat-Killed Lactobacillus plantarum (LP20) on Growth Performance, Digestibility, and Immune Response of Amberjack, Seriola dumerili Juveniles

A 56-day feeding trial was conducted to evaluate the effects of supplemented diets with heat-killed Lactobacillus plantarum (HK-LP) with graded levels of soybean meal (SBM) on growth, digestibility, blood parameters, and immune response of Seriola dumerili (initial weight, 25.05 ± 0.1 g). Seven isonitrogenous and isolipidic practical diets were formulated to contain 0%, 15%, 30%, and 45% SBM, and each SBM level was supplemented with HK-LP at 0.0 and 0.1%. Fish fed diet which contains 30% SBM with HK-LP grew significantly faster than the other groups with notable feed intake and protein retention. Further, protein gain, whole body protein content, protease activity, protein, and lipid digestibility were significantly increased for all fish groups except for fish fed diet which contains 45% SBM with or without HK-LP. Interestingly, lysozyme activity was significantly enhanced in fish fed diets that contain 15% and 30% SBM with HK-LP. Hematocrit, peroxidase, and bactericidal activities revealed a significant increase in 30% SBM with HK-LP group. In addition, fish fed diets which contain 0% and 30% SBM with HK-LP showed higher tolerance against low-salinity stress compared with other groups. In conclusion, the addition of HK-LP to amberjack diets appeared to improve SBM utilization, immune response, and stress resistance.