Shin-ichi Teshima

Effects of dietary lipids, fatty acids, and phospholipids on growth and survival of prawn (Penaeus japonicus) larvae

Abstract The effects of lipids, fatty acids, and phospholipids on growth and survival of larvae of the prawn, Penaeus japonicus , were examined using purified diets containing carrageenan as a binder. P. japonicus larvae did not metamorphose to post-larvae and died in 7 days when fed the diets containing no phospholipid. Growth and survival rate of the prawn larvae were improved by the addition of soybean phosphatidylcholine (PC) to the diets containing 18:1ω9 and essential fatty acids (EFA), or pollack liver oil (PLO) as lipid sources. These results suggest that P. japonicus larvae probably require dietary sources of some phospholipids for growth and survival. The efficacy of phospholipids in improving growth and survival varied with the kinds and sources of phospholipids. Bonito-egg PC, soybean PC, and soybean phosphatidylinositol (PI) had a high efficacy, whereas chicken-egg PC was ineffective. Ovine-brain phosphatidylserine, bonito-egg phosphatidylethanol-amine (PE), and ovine-brain PE improved slightly growth and survival of P. japonicus larvae. The PC and PI containing high proportions of ω6- and ω3-fatty acids as constituents were thought to be effective in improving growth and survival of the prawn larvae. The optimum level of soybean PC for P. japonicus larvae varied with the kinds of coexistent dietary lipids. The best growth and survival were attained on the diets containing 6.0% soybean PC when 18:1ω9 and 1.0% highly unsaturated fatty acids were used as basal lipids. But the inclusion of 3.5% soybean PC was enough to attain optimum growth and survival when PLO was used as the lipid source. The present study did not give a clear picture of the EFA requirements of P. japonicus larvae, although they seemed to vary with dietary phospholipid levels.

Protein and energy requirements of Nile tilapia, Oreochromis niloticus, fry

Abstract The dietary protein and energy requirements of Nile tilapia, Oreochromis niloticus , fry were determined. Fifteen practical diets containing five protein ( 30, 35, 40, 45 and 50%) and three energy (300, 400 and 500 kcal GE/100 g) levels were prepared. The diets were fed to swim-up fry (12 mg) to satiation, three times a day, for 4 weeks. At all protein levels, groups of fry fed low-energy diets (300 kcal/100 g) exhibited extremely poor growth and feed conversion efficiency concomitant with high mortality rates, compared to those fed moderate- (400 kcal/100 g) and high-energy (500 kcal/100 g) diets. At dietary protein levels from 30 to 40%, fish growth and survival rates were significantly improved by increasing dietary energy from 300 to 500 kcal GE/100 g. At 45% protein, the best growth and feed utilization were achieved at 400 kcal/100 g diet with a protein-to-energy (P/E) ratio of 110 mg protein/kcal GE. At 50% protein, no further improvement in fish growth and feed conversion was evident at any energy level. Body composition was significantly affected by both dietary protein and energy levels. At each protein level, body protein and lipid content were positively correlated, while water and ash content were negatively correlated with dietary energy. The present study demonstrated that O. niloticus fry require 45% protein and 400 kcal/100 g for maximum growth when reared under laboratory conditions.

Effects of coating and encapsulation of crystalline amino acids on leaching in larval feeds

Abstract Three types of microparticulate diets for marine larval fish were tested to improve retention of added amino acids after immersion in water. These particle types included microbound, microcoated, and microencapsulated particles. Binding crystalline amino acids to alginate, carrageenan or zein microparticles gave poor results, with leaching of 80–90% of the crystalline amino acids within minutes after immersion in water. Coating microbound diets or crystalline amino acids with tripalmitin had little effect on the retention of crystalline amino acids. Microencapsulation of crystalline amino acids within protein-walled capsules gave better results, with capsules retaining up to 60% of some crystalline amino acids after 2 min in water. The best results were obtained by encapsulating crystalline amino acids within lipid-walled capsules. Retention was further improved by including 2% (w/w) Span 85, a surface-active agent, in the lipid wall of the capsules. With this technique, leaching was reduced to 1.4% when capsules were suspended for 2 min in buffered water (pH 8.5). Feeding studies with olive flounder ( Paralichthys olivaceus ) indicated that larvae older than 20 days could break tripalmitin-walled capsules. Lipid-walled capsules show promising potential for use in nutritional studies with marine fish larvae.

Dietary value of several proteins and supplemental amino acids for larvae of the prawn Penaeus japonicus

Abstract The dietary value of several proteins and supplemental amino acids for larval prawn ( Penaeus japonicus ) was examined using artificial diets containing carrageenan as a binder. As a nitrogen source, casein-gelatin (3:1), casein, and white fish meal had superior nutritive values to gelatin, egg albumin, and an amino acid mixture approximating the composition of casein. The supplementation of a casein diet with crystalline L-arginine HCl improved its nutritive value to that comparable to live food (control). In a subsequent experiment, about half the casein in the casein-based diets was replaced with a mixture of crystalline amino acids, either coated or uncoated with a nylonprotein membrane, and balanced to approximate the amino acid pattern to that of prawn larval whole body protein. Diet containing crystalline amino acids gave survival rates and growth indices equal to or higher than the control group receiving live food. This indicates that prawn larvae are probably able to utilize an amino acid mixture as a partial protein substitute in contrast to juvenile prawns which lack this ability.

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

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 .

Nutritional value of dietary cholesterol and other sterols to larval prawn, Penaeus japonicus Bate

The nutritional value of 11 sterols to larval prawn, Penaeus japonicus, was examined using defined, artificial diets containing carrageenan as a binder. Growth and survival of the prawn larvae fed on a diet with 1.0% cholesterol, 6.0% pollack liver oil, and 3.0% soybean lecithin as lipid sources were similar to those of the control group receiving both Chaetoceros gracilis and Artemia salina nauplii. A sterol-free diet resulted in poor survival and slight retardation of larval development. These results show that the prawn larvae require dietary sources of cholesterol or other sterols as indispensable nutrients. Cholesterol had the highest dietary value among the sterols examined in terms of promoting growth and survival. Ergosterol and 24-methylenecholesterol had a similar dietary value to that of cholesterol. 24-Methylcholesta-5,22-dienol, isofucosterol, and 7-cholestenol also effectively supported growth, whereas stigmasterol, β-sitosterol, 22-dehydrocholesterol, fucosterol, and lanosterol promoted growth weakly or not at all. Isofucosterol, β-sitosterol, and 22-dehydrocholesterol increased the rate of survival of the prawn larvae slightly, but stigmasterol, fucosterol, 7-cholestenol, and lanosterol were ineffective. The results of the present study suggest that P. japonicus larvae are probably incapable of de novo sterol synthesis but may be able to dealkylate some C28 and C29 sterols to cholesterol, which is the most effective sterol.

Biosynthesis of sterols in the lobster, Panulirus japonica, the prawn, Penaeus japonicus, and the crab, Portunus trituberculatus

Abstract 1. 1. In the present study, the sterol-synthesizing abilities of the lobster, Panulirus japonica, the prawn, Penaeus japonicus, and the crab, Portunus trituberculatus, were investigated by using acetate-1-14C. 2. 2. It was found that the three species of marine crustaceans are capable of synthesizing fatty acids and some non-saponifiable materials. However, under the present experimental conditions, these animals did not incorporate acetate-1-14C into sterols.

Quantitative dietary requirements of postlarval tiger shrimp, Penaeus monodon, for histidine, isoleucine, leucine, phenylalanine and tryptophan

Abstract The quantitative requirements of postlarvae Penaeus monodon for essential amino acids were determined through a series of feeding experiments. Test diets contained casein–gelatin as natural proteins supplemented with crystalline l -amino acids (CAAs) at levels based upon the tissue amino acid profile of postlarvae tiger shrimp. Each set of experimental diets contained graded levels of the test amino acid in a range below and above those found in shrimp muscle protein. The dietary CAA mixture was pre-coated with carboxymethylcellulose (CMC), and the diets were additionally bound with CMC, corn starch, and K-carrageenan to prevent leaching of amino acids and other nutrients. P. monodon postlarvae, PL20, mean body weight of 20 mg, were randomly distributed to 30-l fiberglass tanks at a density of 10/tank and each group was fed a particular diet for 56 days. A one-way analysis of variance was used to determine if there were any significant differences in weight gain, survival, and feed conversion among the dietary treatments for each experiments. Regression analysis of the weight gain responses against dietary amino acid levels was used to estimate the amino acid requirements. The optimum dietary requirements for essential amino acids, in percent of the diet, were: 0.8% histidine, 1.01% isoleucine, 1.7% leucine, 1.4% phenylalanine, and 0.2% tryptophan. Expressed as percent of the dietary protein, the requirement values were: 2.2% histidine, 2.7% isoleucine, 4.3% leucine, 3.7% phenylalanine, and 0.5% tryptophan. This information is crucial in optimizing growth and feed efficiency and in developing cost-effective diets for P. monodon.

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.