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1.
The aim of this study was to use the natural dietary markers (stable isotopes and fatty acids) during grow‐out in a biofloc system and for the egg production of Farfantepenaeus brasiliensis shrimp. Egg production was compared for two broodstock origins: biofloc and a wild origin. To delineate the relative contribution to shrimp muscle and eggs, IsoSource software was used. The most important source that contributed to grow‐out shrimp was biofloc ≥250 μm. According to the principal component analysis (PCA) applied to the fatty acid profile of food sources, the first component explains 84.4% of the variability, and the most important source of fatty acids for this component was biofloc ≥250 μm. The most important fresh food sources that contributed to egg production were Artemia biomass, polychaetes and semi‐moist feed for both broodstock origins. According to a PCA analysis of the fatty acid profiles, the most important fresh foods were polychaetes and semi‐moist feed. In conclusion, both isotopic signature and fatty acid profile of the food sources can be used successfully to determine the integration of carbon in the diets of shrimp.  相似文献   

2.
Abstract

Six diet sizes, manufactured from crumbling large pellets, were investigated for their effect on the feeding behavior and growth of Pacific white shrimp, Litopenaeus vannamei. These diets containing 44.7% protein and 8.2% lipid were fed to 0.9 g shrimp for a period of eight weeks under indoor controlled laboratory conditions. Shrimp were stocked at a density of 12 animals per 52 L aquarium (50/m2) and were evaluated for feeding behavior, final weight, growth rate, feed conversion ratio (FCR), and survival. Feeding behavior was observed weekly starting at the beginning of the 4th week until the end of the trial. Results indicated that the variation in diet sizes did not produce significant differences in shrimp growth, FCR or survival. However, shrimp feeding behavior (in terms of total attacking incidents during feeding) was significantly different among diet sizes. This shrimp behavior was observed more frequently in aquaria fed larger diet size (3.0 mm pellet) as compared with those fed smaller diet sizes (0.7 mm and 1.2 mm crumbles). When shrimp were fed larger pellets, some of the individuals obstruct other individuals and monopolize the diet. Such “selfish” behavior of shrimp could result in considerable size variation and severe mortality of smaller individuals, which could be the case when shrimp are reared to market size. The effect of diet size on shrimp feeding behavior deserves further investigation and the use of a continuous monitoring device such as a video camera is strongly recommended. Future study should also consider various shrimp and pellet sizes more meaningful to aquaculture producers.  相似文献   

3.
不同盐度对生物絮团、对虾生长以及酶活性的影响   总被引:1,自引:0,他引:1  
在不同盐度条件下进行凡纳滨对虾的生物絮团养殖试验,研究盐度对生物絮团养殖水质和对虾生长及其酶活性的影响。试验设5个盐度梯度(10、15、20、25、30),生物絮团初始量为20 mL/L,对虾密度为500尾/m^3,试验周期30 d。试验结果显示,15盐度组与20盐度组的对虾体质量增长率最大,达70.73%,10盐度组的体质量增长率最小,达50.24%。盐度越高生物絮团生长越快,30盐度组17 d生物絮团沉降量达200 mL/L,之后逐渐降至43 mL/L,其他组呈相同变化趋势。试验过程中水体总碱度与pH持续降低,但不同组间差异不显著(P>0.05)。盐度越高氨氮累积越快,30盐度组在第6 d达到最大质量浓度8.62 mg/L,之后降至0 mg/L,其他组呈相同趋势变化。盐度越低亚硝态氮累积越快,10盐度组在第6 d达到最大质量浓度9.18 mg/L,之后降至0 mg/L,其他组呈相同趋势变化。硝态氮在不同盐度中呈前期上升的趋势,第16 d之后开始缓慢下降。15盐度组的淀粉酶活性显著高于其他组(P<0.05),其他各组之间无显著差异(P>0.05)。脂肪酶在25盐度组活性最高,盐度升高或者降低酶活性均降低。在10、15、20盐度组中,超氧化物歧化酶、碱性磷酸酶、酸性磷酸酶活性均维持在较高水平,在相同盐度下,肌肉酶活性低于肝胰脏。  相似文献   

4.
A 30‐day experiment was conducted to evaluate inorganic nitrogen control, biofloc composition and shrimp performance in zero‐exchange culture tanks for juvenile L. vannamei offered a 35% (P35) or 25% (P25) crude protein feed, each feed supplemented with additional carbohydrate to increase the C/N ratio to 20:1 (CN20) or 15:1 (CN15). Sucrose was used as a carbohydrate to manipulate the two C/N ratios based on the carbon and nitrogen content of both the feeds and sucrose. The four treatments were referred to as: P35 + CN20, P35 + CN15, P25 + CN20 and P25 + CN15. Each treatment consisted of four replicate tanks (125 L), each stocked with 28 shrimp (equivalent to 224 shrimp m?3). Bioflocs formed and developed based on initial inoculation in all four treatments; and monitored water quality parameters were maintained within acceptable ranges for shrimp culture throughout the experiment. No significant effects (> 0.05) of dietary protein level, C/N ratio or their interaction were observed on biofloc development (BFV, TSS and BFVI) and inorganic nitrogen (TAN, NO2?‐N and NO3?‐N) concentrations. At the end of the experiment, proximate analysis of the bioflocs collected from the four treatments showed crude protein levels of 21.3% ~ 32.1%, crude lipid levels of 1.6% ~ 2.8% and ash levels of 43.4% ~ 61.4%. Extracellular protease and amylase activities of the bioflocs were 9.9 ~ 14.4 U g?1 TSS and 293.5 ~ 403.8 U g?1 TSS respectively. Biofloc composition and enzyme activity were both affected by dietary protein level (< 0.01) and C/N ratio (< 0.05). Survival, per cent weight gain and protein efficiency ratio of shrimp were not affected (> 0.05) by dietary protein level, C/N ratio or their interaction; however, the feed conversion ratios were significantly lower (< 0.05) in treatments with high dietary protein (P35) compared with those in treatments with low dietary protein (P25). The results from this study demonstrate that dietary protein level and C/N ratio manipulation can have important implications for water quality, biofloc composition and shrimp performance in intensive, zero‐exchange biofloc‐based culture systems.  相似文献   

5.
We investigated whether the positive impacts of artificial substrates on shrimp performance are altered in any way by their format or mode of fixation in the tanks. To examine this question, substrates were fixed vertically in the water column in three different configurations: SCF treatment (Substrate Completely Fixed), SPF treatment (Substrate Partially Fixed) and SFF (Substrate in Frond Format). Another treatment received no substrate and served as control (WS = Without Substrate). The shrimp were cultured for 38 days in intensive biofloc culture tanks at a stocking density of 1,125 shrimp m?3. In general, water quality variables were similar among treatments and remained within the appropriate range for shrimp culture. The final biomass was higher (8.5 kg m?3) and the feed conversion ratio (FCR) lower (1.6) in all tanks with substrates when compared with the WS treatment tanks (final biomass = 6.3 kg m?3 and FCR = 3.1). However, only shrimp from the SCF and SPF treatments had a higher survival rate (>95.0%) compared to those in WS tanks (75.9%), which was statistically similar to the SFF treatment (88.0%). These results show that substrate format and its mode of fixation in tanks can alter shrimp performance. In well‐aerated intensive tanks, substrates in frond format are constantly pushed to the tank surface, making it difficult for shrimp to adhere to the screens. In such situation, the extra surface provided by the substrates is not always available to the shrimp, a fact that minimizes the positive effects of substrate.  相似文献   

6.
The aim of this study was to evaluate the effect of light limitation on the water quality, bacterial counts and performance of Litopenaeus vannamei postlarvae reared with biofloc at low salinity (≈9 g L?1). Two treatments were designed: T1 = culture with natural sunlight and T2 = culture in darkness. After 28 days, in both treatments, the final weight of shrimp was over 0.6 g with a specific growth rate over 7.4% d?1, and a survival rate over 70%. In both treatments, Vibrio sp. concentration presented low values (culture with natural sunlight = 0.1 to 9.9 × 102 CFU mL?1, culture in darkness = 0.4 to 11.7 × 102 CFU mL?1) and Bacillus sp. had high values (culture with natural sunlight = 0.7 to 66.0 × 104 CFU mL?1, culture in darkness = 0.7 to 65.8 × 104 CFU mL?1). All water quality parameters remained within the ranges suitable for shrimp culture, except for alkalinity during the first stage of the study. Although in some sampling periods some significant differences were found in bacterial counts and water quality parameters, shrimp productive performance under culture with biofloc at low salinity was not affected significantly by light limitation.  相似文献   

7.
This study evaluated the potential for the replacement of fishmeal (FM) by biofloc meal (BM) in the diet of Litopenaeus vannamei postlarvae. Four isonitrogenous (437.42 g kg?1) and isocaloric (19.84 kJ g?1) diets were formulated, in which FM was replaced with BM at 0% (T0), 7.5% (T7.5), 15% (T15) and 30% (T30). A commercial diet (CD) was used as reference. The study was conducted over 42 days in 50 L tanks connected to a water recirculation system. All tanks were stocked with three postlarvae (initial weight 0.0023 g) per litre. Shrimp survival, weight gain (WG), final weight (FW), specific growth rate (SGR) and protein efficiency ratio (PER) were measured. Survival rates were high (>91.1%) in all treatments. As the T30 treatment returned a significantly (<0.05) better performance in WG, FW, SGR and PER than all other treatments, partial replacement of FM with BM does not appear to affect productivity. In fact, a regression analysis indicated that a FM to BM replacement level of over 20% may actually improve shrimp growth. In addition to providing a cost‐effective alternative ingredient for L. vannamei postlarvae diets, the production of meal also represents a more sustainable way of disposing of the excess of biofloc produced by BFT systems.  相似文献   

8.
9.
Abstract

A feed manufacturing method involving the production of large pellets followed by crumbling to desired diet sizes was used to produce six shrimp diets to determine its effect on growth of three size classes of Pacific white shrimp, Litopenaeus vannamei. The six diets containing 45% protein were 0.7 mm crumble, 1.2 mm crumble, 1.7 mm crumble, 2.2 mm crumble, 2.6 mm crumble, and 3.0 mm pellet. These diets were fed to three size classes of shrimp subjected to a four-week growth trial under indoor laboratory conditions. Stocking density was 12 shrimp/aquarium for size class 1 (1.13iö.01 g), 9 shrimp/aquarium for size class 2 (7.31iö.06 g), and 6 shrimp/aquarium for size class 3 (13.12iö. 10 g). Shrimp were fed three times daily and were evaluated for live weight, growth rate, feed conversion ratio (FCR), and survival. Results for shrimp growth appeared to be affected by diet size and pellet water stability. The effects of diet size, however, were more evident on smaller sized shrimp. Weekly growth rates for class 1 and class 2 shrimp indicated significant responses (P < 0.05) to the effects of diet size, while the class 3 shrimp did not show any significant result. The growth rates for both class 1 and class 2 shrimp were lowest at the smallest diet size (0.7 mm crumble) but differed with respect to highest growth rates. The largest diet (3.0 mm pellets) yielded the highest growth rates for class 1 shrimp, while medium sized feed (2.2 mm crumble) produced the best growth for class 2 shrimp. This could be partly attributed to pellet water stability, which had a direct correlation to diet size (r = 0.97). Smaller diet sizes resulting from crumbling larger pellets tend to have lower water stability. The water stability decreased from 82.5% to 76.3% as the 3.0 mm pellets were reduced to 0.7 mm crumbles. Stress cracks are created during crumbling, and surface area to volume ratio are increased as larger particles are reduced to crumbles. These would make smaller diet particles more susceptible to disintegration and nutrient leaching. For class 3 shrimp, the largest pellets produced the highest growth rate. This high growth value, however, was not significantly different (P > 0.05) from growth results produced by the crumbled feed sizes. This observation suggests that diet sizes ranging from 0.7 mm crumble to 3.0 mm pellet could be used for a 13 g shrimp, although preference would be given to larger pellets due to higher growth performance and better pellet water stability. Results for shrimp live weights were similar to results obtained for weekly growth rates. FCR and survival of all shrimp sizes did not show any significant response from the effects of various diet sizes. However, larger shrimp were less efficient in their diet utilization than smaller shrimp.  相似文献   

10.
Biofloc (consortium of diverse microorganisms associated to suspending substrates) was developed from waste of shrimp Litopenaeus vannamei postlarvae culture under low salinity (5 g L?1) to provide an additional nutritious biomass and reduce fishmeal inclusion in feeds in a 28‐day indoor shrimp nursery trial conducted in 15 experimental containers (250 L stocked at 600 org m?3). Four experimental diets (isoproteic and isocaloric) containing different percentage of fishmeal: 0%, 10%, 20% and 30% substituted by vegetable meal mix (corn, sorghum and wheat) were formulated and elaborated. A control treatment consisted of a commercial feed. The main water quality parameters were monitored, and no significant differences were found among treatments. The growth and survival were similar among treatments. In general, digestive enzymatic activities showed differences being greater in the biofloc system compared with clear water. It was concluded that low‐salinity shrimp nursery could be successfully developed with minimum inclusion of fishmeal in feeds, without significant effect on production response. The adjustment of C : N ratio allowed the increase of microbial biomass in the bioflocs, which contributed to maintain good water quality, provide live food and enhance digestive enzymatic activity of cultured organisms.  相似文献   

11.
The objective of this study was to demonstrate the feasibility of four diets formulated to contain increasing levels (0, 50, 100 and 150 g kg?1 of diet) of grain distillers dried yeast (GDDY) in production diets for Litopenaeus vannamei, reared in outdoor tanks or production ponds. The production pond trial was carried out in 16, 0.1‐ha ponds using four replicates per diet. Juvenile shrimp (38.1 ± 4.26 mg, initial weight) were stocked at 30 shrimp m?2 for a 16‐week period. The same four diets and a commercial reference diet were offered to shrimp maintained in outdoor tanks over a 12‐week period. A total of 20 tanks were stocked with juvenile shrimp (3.05 ± 0.22 g, initial weight) obtained from production ponds at a density of 30 shrimp per tank (40 shrimp m?2). At the conclusion of these trials, mean final weight ranged from 19.77 to 23.05 g, yield ranged between 4760 and 5606 kg ha?1, survival ranged from 69.6% to 89.4%, and feed conversion ratio (FCR) was between 1.02 and 1.23. Shrimp reared in the outdoor tanks confirmed the results of the pond trial. Mean final weight ranged between 18.12 and 18.97 g, survival ranged from 93.3% to 98.3%, and FCR was between 1.25 and 1.29. In both trials, there were no significant differences regarding mean final weight, FCR and survival among dietary treatments. Based on this study, GDDY up to 150 g kg?1 of diet can be used in L. vannamei commercial feed formulation.  相似文献   

12.
13.
The present study assessed the effects of different types of feeds and salinity levels on water quality, growth performance, survival rate and body composition of the Pacific white shrimp, Litopenaeus vannamei, juveniles in a biofloc system. Shrimp juveniles (2.56 ± 0.33 g) were cultured for 35 days in 300 L fibreglass tanks (water volume of 180 L) with a density of 1 g/L in six treatments. Three sources of feed (100% formulated feed, mixture of 66.6% formulated diet and 33.3% wet biofloc, and 100% wet biofloc) and two levels of salinity (10 and 32 ppt) were considered in two control groups and four biofloc treatments. Water quality parameters in the biofloc treatments were significantly better than control groups (p < .05). The highest increase in growth performance and survival rate were obtained in salinity of 32 ppt and mixed feed sources. Analysing the proximate composition of body shrimp indicates an increase in lipid and ash levels in biofloc treatments, which was more evident in the salinity of 32 ppt. In addition, the proximate analysis of shrimp body showed significant differences between biofloc treatments and control groups (p < .05). The highest FCR was found in the treatment with salinity level of 10 ppt and fed only with floc. Overall, it was found that the artificial diet supplemented with biofloc at the salinity of 32 showed better performance in the juvenile stage of Pacific white shrimp.  相似文献   

14.
The effect of promoted biota on the production parameters, water quality, nutritional and immunological condition of Litopenaeus vannamei was assessed in semi‐intensive ponds. Earthen ponds were used as experimental units: three with formulated + natural promoted feed + shrimp (T1), three with formulated feed + shrimp (T2), and three with promoted natural feed without shrimp (Control). The dissolved oxygen (DO) levels were optimal for all treatments (≥6 mg L?1) as well as the pH (8.4–8.6). Total ammonia nitrogen was greater in T2 (0.10 mg L?1) than T1 (0.07 mg L?1) and the Control (0.06 mg L?1). Phytoplankton, zooplankton and benthos were more abundant in T1 and the Control. The promotion of natural feed had a positive effect on all the production parameters of shrimp with an increase of 19.0%, 3.5% and 23.9% in weight gain, survival, and final biomass, respectively; also it was observed a decrease of 13.9% in feed conversion ratio. No differences in haemolymph parameters were observed for nutritional indicators (glucose, cholesterol, proteins, and triglycerides) nor for immunological response (phenoloxidase and prophenoloxidase). The results indicate that the promotion of biotic communities enhances the production parameters of farmed shrimp, without affecting the nutritional and immunological status. Also the water quality was improved by the presence of biota.  相似文献   

15.
The objective of this study was to evaluate the influence of different dietary lipid and fatty acids on the nutritional value of bioflocs used as a feed, as well as shrimp performance and health. A total of 1800 Litopenaeus vannamei juveniles (2.87 ± 0.01 g) were cultured in biofloc technology, with a density of 200 shrimp m?2, and fed with three isoproteic experimental diets at different lipid levels (85 g kg?1, 95 g kg?1 and 105 g kg?1); each treatment was performed in triplicate. After 61 days, no significant difference was observed (> 0.05) among the water quality parameters. For the shrimp performance, significant difference was observed (= 0.011) among the values of survival, where treatments with lower lipid levels had higher survival (92.5 ± 3.5% and 91.0 ± 2.5%). Although there are significant differences in survival, no significant differences in the total haemocytes count (THC) were observed. For other growth performance, no differences were observed (> 0.05). A positive correlation (= 0.75) has been observed between the dietary oleic acid and bioflocs. The bioflocs showed ‘long‐chain’ polyunsaturated fat acids (lcPUFA), especially arachidonic acid. The shrimp showed similar growth and stayed healthy at the end of the experimental period.  相似文献   

16.
The antioxidant and oxidative damage responses and immune parameters in shrimp, Litopenaeus vannamei, reared in clear water (CW) and in a biofloc system (BFT) were evaluated. The animals were given feed supplemented with either nanocapsules containing the antioxidant lipoic acid (NCLA) or empty nanocapsules (NC). Antioxidant and oxidative stress analyses were evaluated by measuring glutathione S‐transferase activity (GST), reduced glutathione (GSH) concentration and lipid peroxidation (TBARS) in the gills, hepatopancreas and muscle. The immune parameters were then determined by the differential hemocyte count in the haemolymph. The final weight of the shrimp reared in both CW and BFT and treated with NCLA increased (p < .05). The shrimps reared in BFT showed increased GST activity in the gills and hepatopancreas after NCLA treatment (p < .05). Higher GSH levels were observed in the hepatopancreas with NCLA supplementation in CW and BFT (p < .05). Decreased levels of TBARS were observed in the gills and muscles of shrimp supplemented with NCLA and maintained in CW (p < .05). A decrease in the percentage of hyaline hemocytes and an increase in granular hemocytes were observed in shrimp treated with NCLA in CW and BFT (p < .05). The antioxidant treatment induced positive responses in terms of the zootechnical, biochemical and immunological parameters.  相似文献   

17.
The relative contribution of the dietary nitrogen supplied by fish meal and a biofloc meal to the growth of Pacific white shrimp was evaluated using stable isotope analysis. Biofloculated material was obtained from an experimental tilapia culture system. Five formulated diets were supplied. Two of them consisted in isotopic controls having only fish meal or biofloc meal as protein source. Three mixed diets were formulated with varying proportions of these ingredients on a dietary nitrogen basis (75:25, 50:50 and 25:75). At the end of the trial, survival rates were similar (92–100%) but significant differences in mean final weight were observed and a negative correlation between the inclusion of biofloc meal and weight gain was evidenced. Mean final weight in shrimp fed on diet containing only fish meal was 2.8 g, while mean final weight of animals fed on diet containing 50% biofloc was 1.9 g. Isotopic mixing models indicated that all diets contributed higher proportions of dietary nitrogen from fish meal than from biofloc meal. Dietary nitrogen available in diets containing 25%, 50% and 75% of biofloc meal was incorporated in muscle tissue as 5%, 41% and 64% respectively. Diet supplying 25% of nitrogen from biofloc was the only mixed diet eliciting growth comparable to diet containing only fish meal. Lower growth and nitrogen deposition in shrimp fed on diets containing high proportions of biofloc meal were possibly associated to the use of only two protein sources and a restriction of essential amino acids.  相似文献   

18.
A 7-week experimental study was performed to evaluate the effect of five concentrations of adult live Artemia (0, 1, 2, 3 and 4 L−1) as exogenous natural feed on the water quality and production parameters of juvenile (0.2 ± 0.01 g) shrimp (Litopenaeus vannamei) pre-grown intensively (125 organism m−2) under laboratory conditions (80 L plastic tanks). No significant differences were observed in the environmental variables among treatments. Total ammonium nitrogen, nitrates and phosphates recorded higher concentrations in all the treatments using artemia, as compared with the treatment without Artemia. In all the cases, the levels remained within or close to the ranges considered necessary for the farming of the species. The highest weight gain and biomass were obtained in the treatments with 3 and 4 Artemia L−1. The best feed conversion ratio were recorded using 2 Artemia L−1 and the highest with 0 Artemia L−1. No differences in survival were detected among treatments. The greatest concentrations of nitrogenous metabolites achieved at the highest densities of Artemia were lower than the LC50 for penaied shrimp and no negative effect was observed on the survival of the shrimp. These results clearly indicate that the use of adult live Artemia as exogenous natural feed significantly increased the production parameters of the Pacific white shrimp.  相似文献   

19.
The aims of this study were to evaluate the probiotic efficiency of Bacillus subtilis E20 (109 colony‐forming units kg?1) on the growth and apparent digestibility coefficients (ADCs) of dry matter (DM), crude protein (CP), amino acids (AAs), and crude lipids (CLs) of the white shrimp, Litopenaeus vannamei. A control diet without probiotic supplementation was used. Shrimp exhibited significant increases in growth performance and feed utilization after being fed the test diet for 56 days. Shrimp were then used to evaluate the apparent nutrient digestibility using 0.1% Cr2O3 in the diet as an indicator. During the trial, faeces was collected from triplicate groups of shrimp twice daily. ADCs of CP and DM in the test diet significantly increased compared to those of the control diet. Although the ADCs of CLs did not significantly differ between the control and probiotic group, the ADC of CLs was higher in the probiotic group than in the control group. In addition, ADCs of most AAs in the test diet were significantly higher compared to those of the control diet. These results suggest that shrimp in the test group had significantly better growth performance, which was due to increases in nutrient digestibility and absorption.  相似文献   

20.
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