Suitable dietary chitosan improves the growth performance,survival and immune function of tiger shrimp,Penaeus monodon

Different levels of dietary chitosan on growth performance, survival and stress tolerance to air exposure was studied in tiger shrimp, Penaeus monodon. Shrimp (mean initial wet weight about 1.16 g) were fed with six different diets (C0, C0.05, C0.1, C0.2, C0.3 and C0.4) containing six level of chitosan (0%, 0.05%, 0.1%, 0.2%, 0.3% and 0.4% respectively) in triplicate for 60 days. Growth performance [final body wet weight (FBW); weight gain (WG); biomass gain (BG)] of shrimp fed chitosan‐containing diets were higher (P < 0.05) than that of shrimp fed the basal diet, shrimp fed C0.1 diet showed the highest value of growth performance. Survival of shrimp in C0.1 and C0.2 diet groups were higher (P < 0.05) than that of shrimp in C0, C0.05 and C0.4 diet groups but without statistical difference (P > 0.05) in shrimp fed C0.3 diet group. Whole body and muscle lipid contents decreased with increasing dietary chitosan levels. Plasma total cholesterol and triglyceride contents of shrimp fed C0 diet was significantly higher (P < 0.05) than that of shrimp fed chitosan‐containing diets. Plasma alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities of shrimp fed C0 diet were higher than those of shrimp fed chitosan‐containing diets. Digestive gland malondialdehyde (MDA) and carbonyl protein contents of shrimp fed chitosan‐containing diets were lower (P < 0.05) than that of shrimp fed C0 diet. Total haemocyte count of shrimp fed C0 diet was lower (P < 0.05) than that of shrimp fed chitosan‐containing diets. On the contrary, the haemolymph clotting time of shrimp fed C0 diet was higher (P < 0.05) than that of shrimp fed chitosan‐containing diets. In conclusion, all results suggested that dietary intake containing 0.1% and 0.2% chitosan enhanced the growth of shrimp, whereas a higher level than 0.3% and 0.4% decreased growth of shrimp. Second‐degree polynomial regression analysis of WG and BG indicated that the optimum supplement of dietary chitosan level should be 0.19–0.21%.     

饲料中不同蛋白含量对斑节对虾幼虾生长及消化酶的影响

选用鱼粉、豆粕和大豆浓缩蛋白为主要蛋白源,配置6个蛋白质水平梯度(36%、38%、40%、42%、44%、46%)的饲料,对斑节对虾幼虾(1.03±0.02 g)进行56 d养殖实验,研究饲料中不同蛋白含量对斑节对虾幼虾生长及消化酶活性的影响。结果表明,(1)摄食40%蛋白饲料的斑节对虾的增重率(417.35%)和特定生长率(2.93%·d-1)获得最大值并显著高于36%蛋白饲料组(P<0.05),但与其它各组无显著差异。饲料蛋白水平在38%时的饲料系数(1.88)最低且与44%和46%蛋白饲料组存在显著性差异(P<0.05)。(2)虾体蛋白含量在44%饲料蛋白组最高,且显著高于36%、38%和42%组(P<0.05)。(3)斑节对虾的蛋白质表观消化率在42%蛋白组最高,44%和46%蛋白饲料组的蛋白质效率显著低于36%～42%蛋白饲料组(P<0.05)。(4)随着蛋白水平的提高,斑节对虾的蛋白酶活性呈现由高到低波动的趋势;淀粉酶活性随着饲料蛋白含量的升高而呈下降趋势,胃淀粉酶活性在38%～42%蛋白饲料组显著高于36%蛋白饲料组(P<0.05),肠淀粉酶活性在42%蛋白饲料组显著高于其它各组(P<0.05)。通过饲料中蛋白质含量与增重率的回归分析,斑节对虾幼虾饲料蛋白的适宜含量为39.70%。     

Effects of crushed conspecifics on growth and survival of Penaeus monodon Fabricius post larvae

In the present study, the hypothesis tested was that Penaeus monodon post‐larvae (PL) experience lower growth when exposed to crushed conspecifics, which was achieved by exposing individual P. monodon PL with abundant food for 4 weeks to a gradient from 0 to 100 crushed conspecific PL L^?1. Both dry weight (48.5±7.2 mg) and body size (28.0±1.3 mm) of animals exposed to 1 macerated PL L^?1 were significantly (P≤0.011) higher than those of animals in treatments with 0, 5 and 10 crushed PL L^?1 (average over treatments: 25.6±3.2 mg; 23.4±0.5 mm). All animals died within 1 week when exposed to 70 and 100 crushed PL L^?1, and within 3–4 weeks when exposed to 50 and 30 crushed PL L^?1. Exposure time affected mortality and it appeared that LC₅₀ values decreased from 60 to 13 crushed PL L^?1 from 1 to 4 weeks' exposure. Survival of P. monodon PL was negatively correlated to pH, biological oxygen demand, ammonia and nitrate. In conclusion, low dose of crushed conspecifics has a stimulatory effect on P. monodon PL, as larvae were heavier and larger, while high doses cause high mortality.     

EM在水泥池封闭、半封闭式生态养虾中的应用

本实验以EM作为饲料添加剂和水质净化剂,采用全封闭、半封闭与传统养殖方式—对照组在实验室水泥池(118d)养殖实验。结果表明:EM能改良水质条件,促进对虾生长。全封闭和半封闭实验组成活率分别比对照组提高了48 7%,24 1%;饵料系数则降低了21 2%,14 1%;全封闭和半封闭实验组DO含量与对照组相比分别提高了9 4%,12 6%;COD含量与对照组相比分别降低了0 25%,0 48%;NH 2-N含量与对照4-N含量与对照组相比分别降低了19 2%,19 2%;NO 组相比分别降低了15 2%,21 1%。     

The effectiveness of a commercial microbial product in poorly prepared tiger shrimp, Penaeus monodon (Fabricius), ponds

The efficacy of a commercial microbial product was tested in commercial tiger shrimp, Penaeus monodon (Fabricius), ponds for one culture period in Kuala Selangor, Malaysia. Four ponds with replicates for treatment and control were used. The pond bottom was dried but the organic sludge was not removed as normally practised in pond preparation. The ponds were stocked with 15 post‐larvae at the rate of 31.m^?2. Physical, chemical and biological parameters of the pond were analysed every 2 weeks during the culture period. Water quality parameters remained within the optimum range for shrimp culture except for ammonia‐nitrogen being significantly higher in control ponds and silica in treated ponds. Benthic organisms were not found in any of the ponds. The average counts of different bacteria were not significantly higher in treated ponds than control. Because of poor health, the shrimp were harvested earlier (72 days) than the usual 120 days. An average of 875.60 ± 67.00 kg shrimp ha^?1 was obtained in treated ponds with a feed conversion ratio (FCR) of 1.57 ± 0.10 and survival rate of 42.35 ± 5.37% compared with 719.50 ± 130.94 kg shrimp ha^?1, 2.99 ± 0.70 and 21.25 ± 3.26%, respectively, in control ponds. Neither the microbial product nor the frequent water exchange was effective in overcoming the problems caused by the poor pond bottom.     

The effect of dietary lipid and lecithin levels on the growth, survival, feeding efficiency, production and carcass composition of post-larval Penaeus monodon Fabricius

Abstract. Eight semi-purified diets were formulated to investigate the effects of dietary lipid and lecithin levels on the performance and carcass composition of post-larval Penaeus monodon Fabricius.
Supplementary soyabean lecithin levels from 0 to 9% and total dietary lipid (cod liver oil:soyabean oil at a ratio of 3:1) levels from 3·5 to 12·5% at 3% increments were tested in diets that were isonitrogenous and isoenergetic. The diets were fed for 50 days to triplicate groups of post-larval P. monodon held in a laboratory marine recirculated water system.
Despite poor overall performance due to the purified dietary ingredients, the absence of basal lipids and/or lecithin was found to result in the poorest performance. Optimum production was obtained with a diet containing 3% basal lipid and 3% lecithin at a total lipid level of 6·5%. The addition of dietary lecithin (particulariy at 46·63% of the total lipid) at up to 3% in terms of growth, feeding efficiency and production or 6% in terms of survival significantly ( P < 0·05) increased shrimp production. Lecithin was therefore probably acting as a growth, survival and/or phago-stimulant in P. monodon.
The total lipid requirements are consistent with those reported by other workers for penaeid shrimp, and are probably a result of the requirement for essential fatty acids, the stimulant properties of lecithin and the calorigenic effects of high dietary lipid levels.     

饲料蛋白水平对斑节对虾生长、血液生化指标及体成分的影响

研究了蛋白含量为34%、38%和42%的3种饲料对斑节对虾(Penaeus monodon)血液生化指标和体成分组成的影响。实验结果表明,斑节对虾的特定生长率(S GR)在不同的饲料组中均有显著性差异(P0.05),特定生长率随着饲料蛋白水平的上升而上升;存活率(S R)在各饲料组中差异显著(P0.05),在38%蛋白水平饲料组中最高。斑节对虾血液中的谷丙转氨酶(GPT)、谷草转氨酶(GOT)两种酶的活性和总蛋白(TP)、白蛋白(ALB)的含量表现出随着蛋白水平的增加而上升的趋势,且在各饲料组中均有显著性差异(P0.05);血液中葡萄糖(GLUC)的含量也随着饲料蛋白水平的上升而上升,但上升的趋势不明显;血液中甘油三酯(TG)和胆固醇(CHOL)的含量在34%和38%蛋白水平饲料组中趋于一致,在42%蛋白水平饲料组中TG和CHOL的含量均有所上升,CHOL的上升趋势更为明显。随着饲料蛋白水平的增加,斑节对虾全虾蛋白质含量上升;水分含量下降,但下降趋势不明显(P0.05);灰分和脂肪的含量没有规律性的变化。     

Evaluation of cholesterol additions to a soyabean meal-based diet for juvenile Pacific white shrimp, Penaeus vannamei (Boone), in an outdoor growth trial

Cholesterol is considered a required nutrient for penaeid shrimps, but an optimal level has not been defined. A 68-day grow-out trial was conducted in 1300-L outdoor tanks in Hawaii, USA, to determine the cholesterol level required in a soyabean meal-based diet for juvenile Pacific white shrimp, Penaeus vannamei (Boone). Test feeds were prepared by adding six cholesterol levels (1.0-10.2 g kg^?1, as-fed basis) to a standard diet high in plant-protein meals, starch and flour. These feeds were provided to the shrimp three times daily. Harvest weights and weekly growth increments varied significantly among diets. The 2.3 g kg^?1 and 4.2 g kg^?1 cholesterol diets yielded better growth than the 1.0 g kg^?1 and 10.2 g kg^?1 diets. Survival and feed conversion ratios did not vary significantly among diets. Significant dietary cholesterol effects on growth of P. vannamei in conditions resembling commercial grow-out indicate that its inclusion in practical diets at more accurately defined levels is necessary. Optimal cholesterol levels for juvenile shrimp may be lower than those now utilized, and may vary relative to the contribution of free sterols from natural foods in shrimp ponds.     

The effect of dietary n-3 and n-6 fatty acid balance on the growth of the prawn Penaeus monodon

A post-hoc study of the influence of dietary fatty acids of the n-3 and n-6 series on the growth of the prawn, Penaeus monodon showed a clear example of interaction by these nutrients to influence growth. Data from three independent growth studies examining the dietary requirements for linoleic (LOA, 18:2n-6), linolenic (LNA, 18:3n-3), arachidonic (ARA, 20:4n-6), eicosapentaenoic (EPA, 20:5n-2) and docosahexaenoic (DHA, 22:6n-3) acids were standardized through a common reference to allow comparison. Analysis of the variation within the experiments was able to define effects attributable to the individual experiments or the overall dietary n-3 and n-6 levels. A generalized additive model (GAM) indicated that both parameters (experiment, and n-3 and n-6 levels) had significant ( P  < 0.05) effects on growth. Loess nonparametric modelling of the data clearly demonstrates `the effect of relationship' on prawn growth to the levels of dietary n-3 and n-6 fatty acids. The response surface model shows clear effects of both n-3 and n-6, and that the effect of n-3 changes with the level of n-6 (and vice versa). Parametric examination of the relationship ( y =–37.149 x ³ + 160.84 x ² – 118.64 x  + 290.6, r ²=0.492, P  < 0.05) between growth and the ratio between the two fatty acid classes suggested that the optimal ratio of n-3 and n-6 fatty acid is about 2.5 to 1. The results of this study demonstrated that the interaction of the dietary n-3 and n-6 fatty acid classes is an important factor of prawn fatty acid nutrition.     

芽孢杆菌对斑节对虾饲料表观消化率的影响

研究了斑节对虾(Penaeus monodon)饲料中添加不同剂量的芽孢杆菌制剂(Bacillus sp.,109 CFU/g)对饲料干物质、粗蛋白、脂肪、磷、氨基酸和脂肪酸的表观消化率的影响.饲料1(对照组)、饲料2、饲料3、饲料4、饲料5和饲料6中芽孢杆菌制剂的添加量分别为0、1.0 g/kg、2.0 g/kg、3.0 g/kg、4.0 g/kg和5.0 g/kg饲料.养殖实验在室外水泥池进行,每池养虾40尾,每组实验设3个重复.以Y2O3为指示剂,添加量为0.01%,连续收集粪便20 d.6个实验组中,对饲料中各营养素的表观消化率分别为:干物质,74.35%～77.89%;粗蛋白,87.29%～89.01%;脂肪,86.46%～89.67%;磷,35.83%～44.17%;必需氨基酸,93.01%～94.04%;非必需氨基酸,91.05%～92.42%;饱和脂肪酸,86.88%～89.95%;单不饱和脂肪酸,90.39%～93.40%;多不饱和脂肪酸 高不饱和脂肪酸,87.97%～91.32%.对照组的脂肪表观消化率高于饲料2、饲料5和饲料6组,但低于饲料3和饲料4组.饲料3组的脂肪和部分脂肪酸的表观消化率最高.对照组的干物质、粗蛋白、氨基酸和磷的表观消化率最低,芽孢杆菌添加量在1.0～3.0 g/kg饲料范围内,随着芽孢杆菌添加量的增加,表观消化率逐渐上升,饲料4组的表观消化率最高,与其他组相比差异显著(P＜0.05),添加量超过3.0 g/kg的各组,随着芽孢杆菌添加量的增加,表观消化率又逐渐下降.实验结果表明,在饲料中添加适量的芽孢杆菌可以显著的提高干物质、粗蛋白、氨基酸和磷的表观消化率.     

Characterization of bacterial community in intestinal and rearing water of Penaeus monodon differing growth performances in outdoor and indoor ponds

Penaeus monodon provides a high‐quality protein source for humanity, and pond cultured shrimp often presents asynchronous growth. Microbial communities are important for the digestion and immunity of shrimp. Therefore, in this study, we investigated the bacterial characteristics of the intestine and rearing water of asynchronously growing P. monodon that were cultured in outdoor and indoor pond respectively. The results showed that the bacterial community of the rearing water was more complex than that of the intestine; the fast‐growing shrimp in the indoor pond had higher intestinal bacterial diversity. Besides, the dominant bacterial composition of the water was more complex than that of the intestinal. Specifically, the abundance of Proteobacteria in the intestine was consistent with the growth performance of shrimp in the outdoor pond, which was exactly the opposite in the indoor pond. At the genus level, two cyanobacteria, Limnothrix and Cyanobium PCC‐6307, were dominant in the indoor and outdoor water respectively. In the outdoor pond, Bacillus was dominant in the slow‐growing shrimp intestines, while Vibrio was dominant in the fast‐growing shrimp. The intestinal microbes of the fast‐growing shrimp had higher proteasome metabolic capacity. These results can provide new insights into microbiome characteristics involved in the asynchronous growth of shrimp.     

The influence of dietary protein and energy levels on growth and survival of penaeid shrimp

Two feeding experiments were conducted on the effects of levels of dietary protein, carbohydrates and lipids on growth and survival of penaeid shrimp. In the first experiment, a series of 14 semi-purified formulations which contained 28 to 52% protein, 0 to 40% glucose, and 0 to 20% supplemental lipid were fed for a ten-week period. In the second experiment, 12 diets which contained 14 to 32% protein, 0 to 30% starch, and 0 to 10% supplemental lipid were fed for eight weeks. Results from these studies indicated that 28–32% was the optimal protein level and that the addition of starch to the diet enhanced growth whereas supplemental glucose caused a reduction in weight gains. Groups fed diets containing a lipid supplement had poor growth and survival rates.     

Valine requirement of postlarval tiger shrimp, Penaeus monodon Fabricius

The valine requirement of juvenile tiger shrimp, Penaeus monodon Fabricius, was determined. Shrimp postlarvae, PL20, with a mean weight of 14 mg, were randomly distributed in 36 oval 40-L capacity fibreglass tanks at 10 shrimp per tank in a flow-through seawater system and reared for 8 weeks. Postlarvae were fed amino acid test diets containing 400 g kg^?1 protein with casein and gelatine as intact sources of protein. Crystalline L-amino acids were supplemented to simulate the amino acid profile of the shrimp muscle except valine. Valine was added in graded levels to obtain 7, 10, 13, 16, 19 and 22 g kg^?1 of the diet or 18, 25, 33, 40, 48 and 55 g kg^?1 of dietary protein. At termination of the feeding experiment, growth and survival were determined and nutritional deficiency signs noted. The relationship between weight gain and dietary valine level was analysed by the broken-line regression method to derive the valine requirement. The dietary valine requirement of Penaeus monodon postlarvae was found to be 13.5 g kg^?1 of the diet or 34 g kg^?1 of dietary protein. This value was lower than the level found in the shrimp tissue.     

Pharmacokinetics of oxolinic acid in black tiger shrimp, Penaeus monodon Fabricius, and the effect of cooking on residues

This study examined the pharmacokinetics and bioavailability of oxolinic acid (OA) in black tiger shrimp Penaeus monodon Fabricius, in brackish water (salinity 10 g L^?1) at 28–29°C, after intra‐sinus (10 mg kg^?1) and oral (50 mg kg^?1) administration and also investigated the net changes of OA residues in the shrimp after cooking (boiling, baking and frying). The haemolymph concentrations of OA after intra‐sinus dosing were best described by a two‐compartment open model. The distribution and elimination half‐lives were 0.84 and 17.7 h respectively. The apparent volume of distribution at a steady state and the total body clearance were estimated to be 2061 mL kg^?1 and 90.1 mL kg^?1 h^?1 respectively. The bioavailability of OA after an oral administration was 7.9%. The peak haemolymph concentration, the time to peak haemolymph concentration and the elimination half‐life after oral administration were 4.20 μg mL^?1, 4 h and 19.8 h respectively. Oxolinic acid muscle and shell levels increased to a maximum (muscle 1.76 μg g^?1 and shell 8.17 μg g^?1) at 4 h post administration and then decreased with the elimination half‐life value of 20.2 and 21.9 h respectively. Residual OA in muscle and shell was reduced by 20–30% by each cooking procedure examined.     

池塘养殖斑节对虾的生长特性

对池塘养殖的斑节对虾的生长特性进行研究。不同生长发育阶段的1500尾斑节对虾的体长、体重生长参数进行测量和分析。结果表明,(1)池塘养殖斑节对虾体长和体重呈幂函数关系,♂∶W=2·0×10-5×L~(2.9498);♀:W=2·0×10-5×L~(2·9633);(2)同大多数对虾种类一样,斑节对虾也表现出雌、雄生长的差异。养殖前期,雌、雄虾的体长、体重生长差异不明显,雄虾略高于雌虾,在59·6d后,雌虾体长生长速度高于雄虾;雄虾体重的生长拐点出现在144·5d左右,雌虾体重的生长拐点出现在195·3d左右;(3)采用von Bertallanffy生长方程,拟合出池塘养殖斑节对虾体长、体重生长方程为:♂∶Lt=178.9(1-e-0·0093(t-28·2)),Wt=87·97(1-e~(-0·0093(t-28·2)))2·9498;♀∶Lt=233·7(1-e~(-0·0065(t-28·2))),Wt=208·96(1-e~(-0·0065(t-28·2)))2·9633。     

Effect of stocking density on soil,water quality and nitrogen budget in Penaeus monodon (Fabricius, 1798) culture under zero water exchange system

Soil and water interactions and their influence on growth and production in different densities (SD8 & SD16) under zero water exchange were studied in two successive crops of Penaeus monodon in Tamil Nadu, India during 2007 and 2008. Scraping and tilling during pond preparation increased the mineralization rate than scraping only. During crop, there was no significant difference in soil organic carbon and total nitrogen between the SDs. However, as the crop progressed, organic carbon and total nitrogen content of the soil showed significant difference under both the SDs. Between the SDs, nitrate and phosphate content in water significantly differed, whereas the progress of the crop significantly increased both available and total nutrients. Mass balance of nitrogen indicated that applied feed contributed to 97.4–98.5% of input nitrogen, of which nitrogen in sediment accounted for 16.5–27.3%, nitrogen recovery in shrimp was 34.2–43.6% and the nitrogen lost through denitrification and volatilization varied from 4.7% to 34.7%. Zero water exchange system is highly efficient as nitrogen recovery is higher in shrimp and lower in discharge water. Lack of significant difference in metabolites between the SDs indicates the role of aeration and probiotics in sustaining SD16 cultures.     

Effect of Penaeus monodon-type baculovirus (MBV) on survival and growth of larval Penaeus monodon Fabricius

Abstract. The present study attempts to investigate the effect of Penaeus monodon -type baculovirus (MBV) infection on growth and survival of the larval stages of Penaeus monodon Fabricius. The results showed that MBV may significantly retard larval growth and cause mortalities during the larval stage. The MBV-infected larvae of P. monodon varied more in body size than uninfected control shrimp, and were discoloured. To detect the presence of MBV in larval prawn, histopathological techniques and an enzyme-linked immunosorbent assay ( elisa ) were used. Positive diagnoses were routinely detected as early as the zoea 1 stage when ELISA was used.     

Effects of dietary phosphorus level and inorganic source on survival and growth of Penaeus vannamei postlarvae in zero-water exchange culture tanks

Zero-water exchange culture tanks were stocked with Penaeus vannamei postlarvae to compare the effects of (i) three dietary phosphorus levels: 0.4, 0.8 and 1.2 %, and (ii) three dietary inorganic phosphorus sources: CaHPO₄, Na₂HPO₄ and NaH₂PO₄, on postlarvae biological performance, and total reactive phosphorus accumulation in the water (TRPAW). Dietary Ca:P ratio was maintained within a 1:1 to 1:2 ratio. Postlarvae survival was high and not significantly different among treatments. Postlarvae growth was not significantly different, regardless of dietary phosphorus level. TRPAW was significantly higher with increasing level of dietary phosphorus. Dietary inorganic phosphorus source did not have a significant effect on postlarvae growth. No significant differences were found on TRPAW between diets with Na₂HPO₄ and NaH₂PO₄ supplementation at equal dietary phosphorus level. TRPAW was significantly lower with CaHPO₄ than with Na₂HPO₄ or NaH₂PO₄ supplementation at equal dietary phosphorus level. Environmental quality of culture water may be greatly modified through nutritional strategies without negatively affecting shrimp biological performance.     

盐度对斑节对虾蜕壳、存活、生长和饲料转化率的影响

对平均体重1.20±0.05g的斑节对虾（Penaeus monodon）稚虾进行为期30d的养殖试验,分别测定其在不同养殖盐度条件下的蜕壳间期、成活率、特定增长率和饲料转化率。斑节对虾的成活率在盐度5时最低,低于60%,与其它盐度试验组差异显著,而其它试验组之间差异不显著。在5～25盐度范围内,蜕壳间期随着盐度升高而延长,盐度达30以上后又缩短,25时为最大值;盐度5、10和15之间差异显著,15、20、30和35之间差异不显著。特定增长率和饲料转换率随盐度升高呈现双峰的波浪式变化趋势;特定增长率在盐度20（3.18±0.14）%·d^-1和25（2.98±0.26）%·d^-1时达到最高。蜕壳间期与生长率存在极显著的正相关关系（P〈0.001）。在盐度20、25、30时饲料转化率高,分别为（52.76±3.06）%、（54.90±5.14）%和（51.56±7.58）%,与其它盐度试验组之间差异显著。因此,斑节对虾养殖的适宜盐度应为20～30,在此条件下可实现较高的成活率、特定增长率和饲料转换率。