Dietary arginine requirement of juvenile kuruma shrimp Marsupenaeus japonicus (Bate)

The requirements for essential amino acids by kuruma shrimp, Marsupenaeus japonicus (Bate) have not yet been determined using the dose–response method due to poor utilization of crystalline amino acids (CAA). In a previous study, we produced coated CAA that could be used to retard leaching losses. Therefore, to determine the arginine requirement of juvenile kuruma shrimp, a growth study was conducted using test diets containing six levels of coated arginine (from 1.20% to 3.19% of diet) for 42 days. Crystalline amino acids was supplemented to correspond to the amino acid pattern in the whole body protein of the kuruma shrimp except for arginine. To reduce leaching losses, CAA were coated with carboxymethylcellulose (CMC) and diets were further bound with CMC and k‐carrageenan. Test diets were fed to triplicate groups of juveniles (0.25±0.02 g) twice a day. Proximate composition and the amino acid composition of shrimp whole bodies were analysed at the end of the feeding trial. Percent body weight gain (WG), specific growth rate, feed intake, feed efficiency ratio and protein retention efficiency were significantly affected by the dietary arginine concentrations. Estimating the arginine requirement of kuruma shrimp using broken‐line analysis of percent WG resulted in a value of 2.66% of diet or 5.32% of protein. After correcting for leaching of arginine from the diets, the optimum dietary value of arginine for kuruma shrimp was a little lower than the estimated value.     

Effects of water-soluble and fat-soluble choline sources on the performances of juvenile kuruma shrimp, Marsupenaeus japonicus Bate

The present study was undertaken to clarify the effect and interaction of choline chloride (CC) and phosphatidylcholine (PC), the water‐ and fat‐soluble sources of choline, on the performances of kuruma shrimp, Marsupenaeus japonicus juveniles using as response variables such as percent weight gain (%WG), specific growth rate (SGR), survival (SR%), feed efficiency ratio (FER), protein efficiency ratio (PER), proximate composition, fatty acids profile and free choline and PC contents in the whole body of kuruma shrimp. A 40‐day feeding trial was conducted as a 2 × 3 factorial experiment with six test diets containing three levels of CC (0.3, 0.6 and 1.2 g kg^?1) and two levels of soybean PC (SPC; 2 and 4 g kg^?1). Both of the choline sources (CC and SPC) showed a significant interaction (P<0.05) regarding all the evaluated response variables except for the proximate and fatty acid contents. Interestingly, there was a positive effect (P<0.05) of CC observed with increasing its level at the low level of SPC and vice versa. However, the magnitudes of the beneficial effect of CC in terms of the evaluated parameters were changed with the different dietary levels of SPC. Also, the inclusion of higher levels of SPC (4 g kg^?1) or CC (0.6 and 1.2 g kg^?1) diminished the effect of the other source.     

Effects of supplementation of coated crystalline amino acids on growth performance and body composition of juvenile kuruma shrimp Marsupenaeus japonicus

Supplementation of crystalline amino acids (CAA) in shrimp diets is unsuccessful in most cases. In the present study, various pre‐coated CAA were developed to minimize the leaching losses from diets in water and assessed using kuruma shrimp Marsupenaeus japonicus juveniles. Experimental diets were supplemented with coated CAA or non‐coated CAA to simulate the dietary amino acid profile to that found in the whole body protein of shrimp. The four diets contained CAA coated with either carboxymethyl cellulose (CMC) (diet 1), zein (diet 2), k‐carrageenan (diet 3) or agar (diet 4), respectively. Another four diets contained CMC‐coated CAA with the addition of either zein (diet 5), casein‐gelatin (diet 6), zein and k‐carrageenan (diet 7), or casein‐gelatin and k‐carrageenan (diet 8), respectively. The 8 weeks feeding trial demonstrated that the diets containing coated CAA gave significantly higher weight gains than diets containing non‐coated CAA, with the highest value for the diet 6. The diets containing coated CAA also yielded higher feed conversion efficiency, protein efficiency ratio, and specific growth rate than diets containing non‐coated CAA. Leaching trials suggested that shrimp growth performance was improved partly due to the retardation or reduction of CAA leaching by coating them with specific binders.     

日周期性循环变温对刺参耗氧率和排氨率的影响

测定了在日周期性温度波动模式下(15±3℃)刺参(Apostichopus japonicus Selenka)耗氧率、排氨率的变化。结果表明:在15±3℃的周期性温度波动模式下,变温对刺参耗氧率有显著影响(P<0.05),在变温过程中刺参耗氧率随温度的升高而增加,在前24 h内变温组平均耗氧率显著高于对照恒温处理组(P<0.05),在48 h后其日耗氧率均值与恒温组相比已无显著差异(P>0.05)。其大小排列顺序为24 h(0.022 5mgO2·g-1·h-1)>48 h(0.021 5 mgO2·g-1·h-1)>72 h(0.018 7 mgO2·g-1·h-1)>恒温组(0.018 1 mgO2·g-1·h-1)。变温处理下刺参的排氨率随温度的升高而增加,但其24 h～72 h日平均排氨率与恒温对照组相比无显著差异(P>0.05)。本实验中测得的刺参O∶N值在27.01～33.63,且变温对刺参的O∶N值有显著影响(P<0.05),其主要原因是变温处理对刺参的氧代谢产生了显著的影响,分析发现,变温可以使刺参的脂肪和碳水化合物的代谢比率增大,从而影响了刺参O∶N值的变化。     

温度和盐度对橄榄蚶耗氧率和排氨率的影响

测定不同温度(15℃、20℃、25℃、30℃)和盐度(16、21、26、31、36)对橄榄蚶(Estellarca olivacea)呼吸和排泄的影响。结果表明,温度和盐度对橄榄蚶的耗氧率和排氨率都有显著影响(P<0.05)。在15~30℃范围内,橄榄蚶单位软体干质量耗氧率(OR)、排氨率(NR)都随温度的升高而升高,变化范围分别为0.37~0.65 mg/(g.h)和1.74~3.15μmol/(g.h);耗氧率和排氨率与温度(t)之间的相关方程分别为:ORT[mg/(g.h)]=0.323 4e0.1765t(R2=0.9755,P<0.05);NRT[μmol/(g.h)]=1.3788e0.1986t(R2=0.9784,P<0.05)。在16~36盐度范围内,橄榄蚶单位软体干质量耗氧率和排氨率开始时随盐度的升高而降低,在盐度26时达到最小值,然后随盐度的升高而升高,变化范围分别为0.43~0.60 mg/(g.h)和1.75~3.26μmol/(g.h);耗氧率和排氨率与盐度(s)之间的相关方程分别为:ORS[mg/(g.h)]=0.0014s2-0.0751s 1.4312(R2=0.9455,P<0.05,n=30);NRS[μmol/(g.h)]=0.0105s2-0.5728s 9.7114(R2=0.9285,P<0.05,n=30)。     

温度与盐度对云龙石斑鱼幼鱼耗氧率和排氨率的影响

为了研究饱食和饥饿状态下温度(24、27、30和33℃)、盐度(15、20、25、30和33)对云龙石斑鱼幼鱼(Epinephelus groupers)耗氧率(OCR)和排氨率(AER)的影响,采用密闭流水式呼吸实验方法对OCR和AER进行了测定。结果显示:饱食和饥饿状态下,温度、盐度对云龙石斑鱼幼鱼OCR和AER影响均显著(P0.05);当温度为24℃~33℃时,饱食状态下的OCR和AER分别比饥饿状态的提高30.29%~131.84%和131.82%~316.19%。饱食状态下,氧氮比(O∶N)、蛋白质供能比(PSR)、Q10(呼吸)、Q10(代泄)分别为12.54~20.18、27.74%~48.48%、1.21、1.60;而在饥饿状态下分别为25.77~35.90、19.49%~27.19%、1.87、3.41;当盐度为15~33时,饱食状态下OCR和AER分别比饥饿状态的提高100.41%~128.21%、182.19%~382.83%。饱食状态下,O∶N、PSR分别为13.32~20.72、39.47%~49.42%,而在饥饿状态下分别为29.18~30.98、22.59%~23.98%。研究表明,云龙石斑鱼幼鱼的最适生长温度为24℃~27℃,最适生长盐度为30~33。     

盐度和规格对光裸方格星虫耗氧率及排氨率的影响

为研究盐度和规格对光裸方格星虫呼吸代谢的影响,采用实验生态学方法,研究了不同盐度梯度(15、20、25、30和35)对3种规格S(2.11±0.60)g、M(6.31±0.85)g和L(8.80±1.40)g光裸方格星虫耗氧率和排氨率的影响。结果显示,盐度对耗氧率和排氨率影响均显著,盐度和规格的交互作用对耗氧率和排氨率影响极显著。盐度在15~25时,耗氧率(OR)和排氨率(AR)均随着盐度的增加而升高,盐度为25时达峰值,之后随着盐度的增加而降低。耗氧率和排氨率与盐度呈一元二次函数关系,OR和AR与盐度的关系可表示为y=–ax2+bx–c。对于耗氧率,a值的范围是0.030~0.044,b值的范围为1.525~2.252,c值的范围为11.824~20.132;对于排氨率,a值的范围是0.009~0.012,b值的范围为0.455~0.593,c值的范围为4.369~5.275。光裸方格星虫的O/N值范围为4.06~14.28。研究表明,光裸方格星虫代谢的最适盐度为25,且对盐度变化的适应能力较强,可通过调整生理代谢水平来适应低盐或高盐环境。     

Effect of replacing fishmeal with canola meal on growth and nutrient utilization in kuruma shrimp Marsupenaeus japonicus (Bate)

A feeding trial was conducted to assess the nutritional values of canola meal as a substitute for fishmeal in diets for kuruma shrimp using five isocaloric diets (190 kJ kg^?1) prepared by replacing 0%, 10%, 20%, 30% and 40% of fishmeal protein with canola meal protein in CM0, CM10, CM20, CM30 and CM40 diets respectively. Triplicate groups of juveniles (0.19 g) were fed the respective diets for 60 days in tanks. At the end of trial, weight gain (%) and specific growth rate (% day^?1) were not significantly (P > 0.05) different among shrimp fed CM0, CM10 and CM20 diets. However, growth was significantly (P < 0.05) decreased in shrimp fed CM30 and CM40 diets. As with growth performance, feed intake, feed conversion ratio and protein efficiency ratio were also decreased (P < 0.05) in CM30 and CM40 groups. Whole body dry matter, methionine and proline were significantly decreased with canola meal substitution levels. In general, retention efficiency of protein and indispensible amino acids were decreased as canola meal increased in diets. It may be concluded that 20% fishmeal protein can be successfully replaced with canola meal, while supplementation of amino acids or blending with complementary proteins could facilitate higher fishmeal replacements in kuruma shrimp diets.     

Effect of high water temperature on the survival, moulting and food consumption of Penaeus (Marsupenaeus) japonicus (Bate, 1888)

The kuruma shrimp, Penaeus (Marsupenaeus) japonicus (Bate, 1888), is a valuable aquaculture species in Queensland, Australia. The shrimp is supplied live to the Japanese market and must survive emersed transport for up to 36 h. In-transit mortality after harvest from high water temperatures (> 30 °C) has been reported by the industry, and a knowledge of the effects of high water temperature may provide important information for producers on grow-out management, timing of production and farm location. Experiments were conducted to determine the effect of high water temperature on survival, moulting and food consumption in P. japonicus. Replicated groups of 15.6 ± 0.2 g shrimp were acclimated and exposed to five temperatures, between 28 and 36 °C, for up to 28 days. Mortality was highest at 36 °C and equally lowest between 28 °C and 32 °C. Intermoult period was not significantly different for temperatures between 28 and 32 °C (19.8–15.5 days) but was significantly greater above 32 °C (27.4 days at 34 °C and > 104 days at 36 °C). There was evidence of moulting synchrony at 28 °C. Mean daily food consumption was highest at 32 °C at 2.34% of body weight, but decreased to 1.56% at 28 °C and 1.33% at 36 °C. Over the range of water temperatures examined, survival, moulting rate and food consumption were highest at 32 °C.     

Vitamin C requirement of kuruma shrimp postlarvae, Marsupenaeus japonicus (Bate), using l-ascorbyl-2-monophosphate-Na/Ca

l ‐ascorbyl‐2‐monophosphate‐Na/Ca (AMP‐Na/Ca) was used as a vitamin C source to investigate the ascorbic acid (AsA) requirements on growth performance and stress resistance of the post‐larval kuruma shrimp, Marsupenaeus japonicus. Purified carrageenan‐microbound diets with six levels of AMP‐Na/Ca, AsA equivalent to 0, 20, 56, 87, 759 and 1697 mg kg^?1 diet were fed to triplicate groups of M. japonicus (mean initial weight 16±0.3 mg) for 30 days. The diets with AsA 0, 20 and 56 mg kg^?1 showed high cumulative mortality after 10 days of feeding. After the 30‐day trial, the shrimp fed these diets had significantly lower survival and weight gain (WG, %) than those fed the 87, 759 and 1697 mg AsA kg^?1 diets. Specific growth rate and individual dry weight showed the same pattern as WG (%). There were no significant differences in growth performance among the groups fed the AsA levels at 87, 759 and 1697 mg kg^?1 at the termination of feeding trial. Broken‐line regression analysis indicated that 91.8 mg AsA kg^?1 in the diet was the optimum for post‐larval shrimp. On the other hand, dietary level of more than 800 mg AsA kg^?1 was needed to ensure high resistance to stressful conditions such as osmotic and formalin stressors.     

Genetic variation of wild and cultured populations of the Kuruma prawn Marsupenaeus japonicus (Bate 1888) using microsatellites

The microsatellite DNA technique was used to detect the genetic variations between wild and cultured populations of Kuruma prawn Marsupenaeus japonicus Bate 1888. All the six microsatellite loci screened in this study showed high polymorphism for their PIC (0.6701–0.8989), which was much more than the standard value of 0.5. A total of 73 alleles were observed over six loci from 93 shrimps. The mean number of allele locus ranged from 9.83 (cultured) to 11.83 (wild). The number of effective alleles varied from 6.86 (cultured) to 8.58 (wild). The average of observed heterozygosity (H_o) of populations varied from 0.6935 (cultured) to 0.7370 (wild), and that of expected heterozygosity (He) was 0.8169 (wild) and 0.8209 (cultured). Tests of Hardy–Weinberg showed that these loci deviated significantly or highly significantly in one or both populations. Compared with the wild population, the cultured population showed little reduction in genetic variation. The total number of alleles (71, 59) was not significantly (P=0.296) different between wild and cultured populations. The paired‐samples t test of observed heterozygosity and expected heterozygosity implied that there was no significant difference (P=0.572 and 0.891 respectively) between wild and cultured populations. However, some rare allele loss might have occurred in the cultured population. A total of 14 unique alleles were found in the wild population, but only two unique alleles were observed in the cultured population. Therefore, there is a need to monitor genetic variability of cultured population, and to improve the hatchery program for the conservation of wild Kuruma prawn resources.     

Effect of salinity on survival, growth, oxygen consumption and ammonia-N excretion of juvenile whiteleg shrimp, Litopenaeus vannamei

In this study, we tested the lower salinity tolerance of juvenile shrimps (Litopenaeus vannamei) at a relatively low temperature (20 °C). In the first of two laboratory experiments, we first abruptly transferred shrimps (6.91 ± 0.05 g wet weight, mean ± SE) from the rearing salinity (35 000 mg L^?1) to salinities of 5000, 15 000, 25 000, 35 000 (control) and 40 000 mg L^?1 at 20 °C. The survival of L. vannamei juvenile was not affected by salinities from 15 000 to 40 000 mg L^?1 during the 96‐h exposure periods. Shrimps exposed to 5000 mg L^?1 were significantly affected by salinity, with a survival of 12.5% after 96 h. The 24‐, 48‐ and 96‐h lethal salinity for 50% (LS₅₀) were 7020, 8510 and 9540 mg L^?1 respectively. In the second experiment, shrimps (5.47 ± 0.09 g wet weight, mean ± SE) were acclimatized to the different salinity levels (5000, 15 000, 25 000, 35 000 and 40 000 mg L^?1) and then maintained for 30 days at 20 °C. Results showed that the survival was significantly lower at 5000 mg L^?1 than at other salinity levels, but the final wet weight under 5000 mg L^?1 treatment was significantly higher than those under other treatments (P<0.05). Feed intake (FI) of shrimp under 5000 mg L^?1 was significantly lower than those of shrimp under 150 00–40 000 mg L^?1; food conversion efficiency (FCE), however, showed a contrasting change (P<0.05). Furthermore, salinity significantly influenced the oxygen consumption rates, ammonia‐N excretion rates and the O/N ratio of test shrimps (P<0.05). The results obtained in our work provide evidence that L. vannamei juveniles have limited capacity to tolerate salinities <10 000 mg L^?1 at a relatively low temperature (20 °C). Results also show that L. vannamei juvenile can recover from the abrupt salinity change between 15 000 and 40 000 mg L^?1 within 24 h.     

盐度和pH对缢蛏耗氧率及排氨率的影响

缢蛏(Sinonovaculaconstricta)分为壳长约4 0、5 0、6 0cm3组。通过实验生态学方法研究缢蛏在不同盐度和pH下的耗氧率和排氨率变化规律。结果表明,盐度对缢蛏的耗氧率和排氨率有极显著影响(F>F0.01),且缢蛏单位体重耗氧率、排氨率随其个体的增大而变小;当盐度为6～30时,缢蛏的耗氧率和排氨率呈1个峰值变化,在盐度22时均达到最大值。pH对缢蛏的耗氧率无显著影响(FF0.01),此时,缢蛏的排氨率出现1个峰值变化,当pH为8时达到最大值。     

pH、盐度和温度对海蜇耗氧率和排氨率的影响

为探究环境因子对海蜇耗氧率(oxygen consumption rate,OCR)和排氨率(ammonia excretion rate,AER)的影响,实验通过室内培养,测定了不同pH值、盐度和温度条件下,海蜇幼蜇和成蜇的OCR和AER的变化特征。结果显示,海蜇伞径与干重可用W=0.002 2e^0.1248D表示,R²=0.972 4。海蜇幼蜇和成蜇的OCR和AER受pH值、盐度和温度影响显著。海蜇幼蜇和成蜇的AER和OCR随pH值的升高呈现先增大后减小的趋势,幼蜇和成蜇的2种代谢率分别在pH值为7.0和7.5时达到最大值,同时收缩次数最多。海蜇幼蜇和成蜇的AER和OCR随盐度的升高呈现先增后减的趋势,分别在盐度为25和20时达到峰值;盐度为20时收缩力最强。不同规格海蜇的OCR随温度升高而增加;AER则随温度升高呈先增大后减小的趋势,25°C达到峰值。海蜇在21°C时运动和进食最快,温度低于3°C或高于35°C海蜇则停止运动。幼蜇的AER Q₁₀值为0.767～4.362,OCR Q₁₀值为1...     

Growth performance of juvenile kuruma shrimp,Marsupenaeus japonicus (Bate) fed diets replacing fishmeal with soybean meal

A feeding trail was conducted to evaluate the effect of lowering dietary fishmeal (FM) levels while increasing levels of dehulled soybean meal (SBM) on growth, nutrient utilization and body composition of juvenile kuruma shrimp, Marsupenaeus japonicas. Five experimental diets were formulated to be isoenergetic, isolipidic and isonitrogenous with decreasing FM levels from 40 to 16% while increasing SBM from 0 to 33% respectively. Quadruplicate groups of shrimp (initial wt = 1.5 g) were fed the test diets for 56 days under the flow‐through system. There were no significant differences in final weight (g) and specific growth rate (SGR, % day) among shrimp fed FM40, FM34, FM28 and FM22 diets respectively. Growth parameters significantly decreased in shrimp when fed FM16 diet, which was the lowest level of FM. Feed intake was positively correlated with the SGR of shrimp, and the lowest one was found in shrimp fed FM16 diet. Protein gain and retention, whole body lipid, arginine and methionine significantly decreased in FM16 fed group. Thus, it is concluded that dietary FM could be reduced down to 22% with SBM without compromising growth, nutrient utilization and retention, and whole body composition of kuruma shrimp.     

Interactive effect of two methyl‐group sources on the growth and phospholipids’ content of kuruma shrimp Marsupenaeus japonicus Bate post‐larvae

Six micro‐bound diets were formulated to contain three levels of choline chloride (CC) (0.0, 0.6 and 1.2 g kg⁻¹) and 2 levels of methionine (Met) (0 and 15 g kg⁻¹). Soybean protein isolates (SPI) were used as the main protein source for its limited Met content. A significant (P < 0.05) interaction was determined between CC and Met on the survival (S %), weight gain (WG%), specific growth rate (SGR % day⁻¹), feed efficiency ratio (FER), protein efficiency ratio (PER) and phosphatidylcholine (PC), phoshphatidylethanolamine (PE) and Met contents of the whole body of shrimp. The shrimp group did not receive either supplemental CC or Met showed lower (P < 0.05) values of the above‐mentioned parameters than other shrimp groups fed with 0.6 and 1.2 g kg⁻¹ supplemental CC with or without Met supplementation. The present study showed that supplementation of 1.2 g kg⁻¹ CC in the diets could compensate shrimp post‐larvae with the needed methyl group when received Met‐deficient diets. The study also assumed that the biosynthesis of PC in the shrimp’s body can be achieved by the methylation of PE through the S‐adenosylmethionine (SAM) pathway and/or through the cytosine di‐phosphoryl (CDP) choline pathway directly from dietary choline.     

温度、盐度和 pH 对鲻幼鱼耗氧率、排氨率以及窒息点的影响

采用封闭流水式实验方法,研究了不同温度(12、16、20、24、28、32℃)、盐度(5、10、15、20、25、30)和pH(7.2、7.7、8.2、8.7、9.2、9.7)对体质量(0.21±0.03)g的鲻(Mugil cephalus)幼鱼耗氧率和排氨率的影响.结果表明,温度(X)对鲻幼鱼耗氧率(Yo)和排氨率(YN)的影响显著,其两两间的相关关系可分别用一元二次方程Yo=-0.0256x2+0.2191X-0.1054(P＜0.05)和YN=-0.0054X2+0.044 1X-0.0082(P＜0.01)表示.随着温度的升高,鲻的耗氧率和排氨率呈现相同的变化趋势,均为先升高后降低,在24℃时,耗氧率和排氨率都达到最大值.经单因素方差分析得出盐度对鲻幼鱼耗氧率的影响极显著(P＜0.01),当盐度在5～30时,随着盐度的升高,耗氧率先下降再升高,然后再下降;排氨率则先升高后降低.经方差检验,盐度对鲻幼鱼排氨率的影响差异极显著,两者之间的相关关系式为YN=-0.0013X2+0.0027X+0.047(P＜0.01).pH对鲻幼鱼耗氧率的影响差异极显著,随着pH的升高,耗氧率呈先升高后下降的趋势,两者之间的关系可用一元二次方程Yo=-0.02583X2+0.198X+0.0775(P＜0.01)表示;pH对鲻排氨率的影响差异极显著,两者之间的相关关系式为YN=-0.0032X2+0.0217X+0.003(P＜0.01).温度和pH对鲻幼鱼窒息点的影响极显著(P＜0.0),盐度对鲻幼鱼窒息点的影响显著(P＜0.05),但对鲻的窒息时间没有显著影响(P＞0.05).     

饥饿及恢复投喂对刺参生长、耗氧率和排氨率的影响

在水温(16±1)℃、盐度27.6±0.5、pH值7.5~8.3条件下,将体重为(28.47±2.02)g的刺参Apostichopus japonicus分别饥饿0(空白对照)、5、10、15和20d(分别记为T0、T5、T10、T15和T20)后再饱食投喂至40d。实验结果表明,随着饥饿时间的延长,刺参的耗氧率呈急速下降、上升、再下降的变化规律;排氨率呈先上升、后下降的变化规律;氧氮比呈先下降、后上升的变化规律。饥饿结束时刺参的体重,除T5组外,其余各组均显著小于T0组(P0.05),且各自均有不同程度的下降,耗氧率和排氨率与T0组比较均呈显著性差异(P0.05)。饥饿对刺参O/N比值的影响显著(P0.05),饥饿初期刺参O/N比值平均为10左右,随着饥饿时间的延长,刺参O/N比值降为小于7。实验结束时,各饥饿组刺参的体重和特定生长率均小于T0组(P0.05),除T5组外,各组的耗氧率和排氨率,均未能恢复至T0组水平(P0.05)。可见,饥饿后恢复投喂的刺参不具有补偿生长的特征。     

Assessment of requirement values for essential amino acids in the prawn, Marsupenaeus japonicus (Bate)

The requirements of juvenile prawn, Marsupenaeus japonicus (Bate), 0.79 g initial body weight, for essential amino acids (EAA) were evaluated based on the daily increase of each EAA in the whole body when the prawn was maintained on a diet with a high nutritive value (a casein‐squid protein‐based diet). The quantities of each EAA needed daily for growth and maintenance of prawn are conceived to correspond to the daily requirements of this prawn species for EAA. Therefore, these requirement values of respective EAA should be supplied from dietary proteins. To determine these values, protein and amino acids of the whole body of the prawn were quantified before and after feeding experiments, and the quantities of respective EAA needed to meet the requirements were estimated based on the EAA profile of the whole body protein of prawn. As a result, the contents of EAA in dietary proteins (%) needed to meet the requirements of the prawn for EAA were assessed to be: threonine (2.3), methionine (1.3), valine (2.4), isoleucine (2.3), leucine (3.4), phenylalanine (2.6), lysine (3.2), histidine (1.1), arginine (2.9) and tryptophan (0.6), respectively, when the prawn are fed 50% protein diet with 90% protein digestibility at a ration size of 2% (% of body weight).