Effect of the addition of diatoms (Navicula spp.) and rotifers (Brachionus plicatilis) on water quality and growth of the Litopenaeus vannamei postlarvae reared in a biofloc system

The aim of this study was to evaluate the effect of the addition of Navicula spp. and Brachionus plicatilis on water quality and growth of postlarvae shrimp Litopenaeus vannamei reared in a biofloc system. Four treatments were considered: a control (biofloc system – BFT); BFT with the addition of Navicula spp. (BFT‐N); BFT with the addition of Brachionus plicatilis (BFT‐B) and BFT with the addition of Navicula spp. and Brachionus plicatilis (BFT‐NB), each in triplicate. Shrimp (16.2 ± 0.03 mg) were stocked at a density of 2500 shrimp m^?3 and plankton were added on days 1, 5, 10, 15, 20, 25 and 30 at a density of 5 × 10⁴ cells mL^?1 (Navicula spp.) and 30 organisms L^?1 (Brachionus plicatilis). The shrimp were fed a formulated feed in four daily rations composed of 40% crude protein and 8% lipids. Significant differences between treatments were observed for final weight, yield, feed conversion ratio, specific growth rate, protein efficiency ratio and protein content of the shrimp. The combined plankton addition of Navicula spp. and B. plicatilis had better performance parameters, indicating their benefit as natural food sources for postlarvae L. vannamei in biofloc systems.     

Effects of bioflocs on dietary protein requirement in juvenile whiteleg Shrimp,Litopenaeus vannamei

A feeding trial was carried out to determine the effects of bioflocs on dietary protein requirement in juvenile whiteleg shrimp, Litopenaeus vannamei. Four bioflocs treatments (BFT) and one control group were managed: BFT fed diets 25% of crude protein (CP) (BFT‐25%), 30% CP (BFT‐30%), 35% CP (BFT‐35%) and 40% CP (BFT‐40%), and clear water control without bioflocs fed with 40% CP (CW‐40%). Triplicate groups of shrimp (initial body weight, 1.3 g) were fed one of the test diets at a ratio of 7% body weight daily for 8 weeks. At the end of the feeding trial, significantly (P < 0.05) higher weight gain and specific growth rate were obtained in shrimp fed BFT‐35% and BFT‐40% compared to BFT‐25% and BFT‐30%. Shrimp fed BFT‐35% exhibited the lowest feed conversion ratio. Significantly higher muscle nucleic acid indices were also recorded such as DNA content in BFT‐30%, RNA content in BFT‐35% and RNA/DNA ratio than that of shrimp fed control. Total protein level in the haemolymph of shrimp fed BFT‐40% was significantly higher than those of shrimp fed BFT‐25% and BFT‐30%. Therefore, the present results demonstrated that, when L. vannamei juveniles were reared in bioflocs‐based tanks, dietary protein level could be reduced from 40% to 35% without any adverse effect on shrimp growth performance, body composition and haemolymph characteristics. [Correction added on 20 May 2015, after first online publication: sentence modified to clarify the reduction in dietary protein level.].     

Effect of using sodium bicarbonate to adjust the pH to different levels on water quality,the growth and the immune response of shrimp Litopenaeus vannamei reared in zero‐water exchange biofloc‐based culture tanks

The bioflocs technology proved to be a sustainable technique used in zero‐water exchange shrimp culture systems. However, the pH and alkalinity may decrease due to the biofloc formation process and Nitrification. A 48‐day experiment was performed to investigate the effects of different pH (7.1–7.6; 7.6–8.1) conditions on water quality, the growth and the health status of shrimp in biofloc technology (BFT) through using sodium bicarbonate to adjust pH respectively. Two pH treatments and one control were compared: T0 — control, T1 — pH 7.6 — NaHCO₃, T2 — pH 8.1 — NaHCO₃, each treatment consisted of three replicate tanks (90 L water volume) and each replicate stocked with 30 shrimp (equivalent to 333 shrimp m^?3). Significant physical, chemical and biological differences (P < 0.05) were detected among treatments. At the end of the experiment, water quality, the growth and the immune response of shrimp in control were significantly lower (P < 0.05) than the other treatments. Moreover, the T2 treatment had a better performance in these three aspects. The results indicated that it was necessary to adjust the pH and alkalinity in the BFT, and a higher pH as well as alkalinity for shrimp growth and the stability of the BFT were more favourable.     

Shrimp (Litopenaeus vannamei) production and stable isotope dynamics in clear‐water recirculating aquaculture systems versus biofloc systems

Closed recirculating aquaculture systems (RAS) offer advantages over traditional culture methods including enhanced biosecurity, the possibility of indoor, inland culture of marine species year‐round and potential marketing opportunities for fresh, never‐frozen seafood. Questions still remain regarding what type of aquaculture system may be best suited for the closed‐system culture of marine shrimp. In this study, shrimp (Litopenaeus vannamei) were grown in clear‐water RAS and in biofloc‐based systems. Comparisons were made between the system types with respect to water quality, shrimp production and stable isotope dynamics used to determine the biofloc contribution to shrimp nutrition. Ammonia and nitrite concentrations were higher, and shrimp survival was lower in the biofloc systems. Although stable isotope levels indicated that biofloc material may have contributed 28% of the carbon and 59% of the nitrogen in shrimp tissues, this did not correspond with improved shrimp production. Overall, the water column microbial communities in biofloc systems may be more difficult to manage than clear‐water RAS which have external filters to control water quality. Biofloc does seem to offer some nutritional contributions, but exactly how to take advantage of that and ensure improved production remains unclear.     

Effect of the addition of Chaetoceros calcitrans,Navicula sp. and Phaeodactylum tricornutum (diatoms) on phytoplankton composition and growth of Litopenaeus vannamei (Boone) postlarvae reared in a biofloc system

The aim of this study was to evaluate the effect of the addition of Chaetoceros calcitrans, Navicula sp. and Phaeodactylum tricornutum (diatoms) on phytoplankton composition and the growth of Litopenaeus vannamei postlarvae reared in a biofloc system . Four treatments were used: BFT (biofloc system without feed and no addition of diatoms); BFT‐F (biofloc system with feed and no addition of diatoms); BFT‐D (biofloc system with the addition of diatoms and no feed); and BFT‐FD (biofloc system with the addition of feed and diatoms), all in triplicate. The shrimp (16 ± 0.02 mg) were stocked at 2500 postlarvae m^?3 and fed a commercial feed. Diatoms were added on the 1st, 5th, 10th and 15th day at a density of 5 × 10⁴ cells mL^?1 for each species. No significant differences (P > 0.05) between treatments were observed for gross primary production, net ecosystem production and water column respiration rate. However, significant differences (P < 0.05) were observed for nitrite, orthophosphate, alkalinity, final weight, weight gain, yield, feed conversion ratio (FCR), phytoplankton and cyanobacteria composition. The BFT‐FD treatment had better performance parameters for final weight (270 mg), weight gain (254 mg), yield (0.67 Kg m^?3) and FCR (0.61), indicating the benefits of the diatoms C. calcitrans, Navicula sp. and P. tricornutum for decreasing cyanobacteria and improving growth of L. vannamei postlarvae reared in biofloc systems.     

Partial replacement of fishmeal with biofloc meal in the diet of postlarvae of the Pacific white shrimp Litopenaeus vannamei

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.     

Effects of addition of Navicula sp. (diatom) in different densities to postlarvae of shrimp Litopenaeus vannamei reared in a BFT system: Growth,survival, productivity and fatty acid profile

The objective of this study was to evaluate the effect of the addition of Navicula sp. on the growth and fatty acids profile of Litopenaeus vannamei postlarvae in a biofloc system (BFT). Four treatments were used: BFT; BFT 2.5N (addition of 2.5 × 10⁴ cells/ml of Navicula sp.); BFT 5N (addition of 5 × 10⁴ cells/ml of Navicula sp.) and BFT 10N (addition of 10 × 10⁴ cells/ml of Navicula sp.), all in triplicate. The shrimp (1 ± 0.01 mg) were stocked at a density of 3,000 postlarvae/m³ and fed with commercial feed. The diatom was added every 10 days, and at the end of 42 days, shrimp performance, water quality and proximal composition were evaluated. The BFT 5N and BFT 10N treatments had higher performance values, highlighting the values of productivity (2.30 and 2.42 kg/m³) and specific growth rate (15.92 and 16.08%/day), which were higher than the other treatments. In addition, the highest levels of fatty acids were observed in treatments with diatom (BFT 5N and BFT 10N), indicating the benefits of Navicula sp. on growth enhancement and fatty acid content of L. vannamei postlarvae grown in biofloc systems.     

The contribution of diatoms to bioflocs lipid content and the performance of juvenile Litopenaeus vannamei (Boone, 1931) in a BFT culture system

This study aimed to evaluate the contribution of three diatom species on the lipid content of bioflocs, their permanence on the bioflocs and influence on the growth performance of juvenile shrimps. Juveniles of Litopenaeus vannamei were reared (30 days; three replicates per treatment) in biofloc systems inoculated with diatoms Amphora coffeaeformis (A), Cylindrotheca closterium (C), Conticribra weissflogii (W), or biofloc only (BF, chlorophycean rich). Water quality parameters were monitored daily and the microbiota on days 1, 10, 20 and 30. The lipid content and fatty acid profiles of bioflocs were analyzed at the end of the experiment. Shrimp survival rate (99%) at treatment A was significantly higher than at BF. The bioflocs in A treatment presented the highest lipid content, differing significantly from BF and W. The content of EPA (20:5) (n‐3) was significantly higher in A and lower in BF, while linoleic acid (18:2) (n‐6) was significantly higher in BF. The results indicate that high cell density of diatoms can be successfully maintained with silicate addition in biofloc systems and that the pennate A. coffeaeformis and the centric C. weissflogii are potentially better suited than the pennate C. closterium as food supplements for shrimp diets in biofloc nurseries system.     

Nursery performance of Pacific white shrimp (Litopenaeus vannamei Boone, 1931) cultivated in a biofloc system: the effect of adding different carbon sources

Effect of different carbon sources on nursery performance of Pacific white shrimp (Litopenaeus vannamei) cultivated in biofloc system was investigated. Shrimp postlarvae (98.47 ± 8.6 mg) were fed for 32 days in tanks with water volume of 130 L and density of 1 individual L^?1. One control treatment and four biofloc treatments (BFT1, BFT2, BFT3 and BFT4) with adding different carbon sources including molasses, starch, wheat flour and mixture of them, respectively, were considered at equal weight ratios. According to the results, salinity, dissolved oxygen and pH were not significantly different among the biofloc treatments (P > 0.05). Maximum pH (8.27) and maximum dissolved oxygen (6.35 mg L^?1) were recorded in the control. Maximum (0.43 mg L^?1) and minimum (0.09 mg L^?1) ammonia were recorded in the control and BFT2, respectively (P < 0.05). Using simple carbohydrates (molasses and starch) lowered the ammonia concentration significantly. The highest increase in body weight (1640.43 ± 231.28 mg), growth rate, specific growth rate (8.97 ± 0.42% per day) and biomass (190.29 ± 26.83 mg) were found in BFT1 and the highest survival (90 ± 0.77%) was found in BFT4. The highest feed conversion (1.52 ± 0.23) and the lowest feed efficiency (66.81 ± 7.95) were observed in the control (P < 0.05). The proximate composition analysis revealed an increase in lipid and ash in biofloc treatments. Results indicated that using biofloc technology with zero‐water exchange system and adding carbon sources could help to recycle waste and improve the water quality. Moreover, the type of carbonaceous organic matter as a substrate for heterotrophic bacteria would be effective in degradation and metabolization of ammonia and nitrite.     

Effect of different biofloc system on water quality,biofloc composition and growth performance in Litopenaeus vannamei (Boone, 1931)

The experiment was conducted with three biofloc treatments and one control in triplicate in 500 L capacity indoor tanks. Biofloc tanks, filled with 350 L of water, were fed with sugarcane molasses (BFT_S), tapioca flour (BFT_T), wheat flour (BFT_W) and clean water as control without biofloc and allowed to stand for 30 days. The postlarvae of Litopenaeus vannamei (Boone, 1931) with an Average body weight of 0.15 ± 0.02 g were stocked at the rate of 130 PL m^?2 and cultured for a period of 60 days fed with pelleted feed at the rate of 1.5% of biomass. The total suspended solids (TSS) level was maintained at around 500 mg L^?1 in BFT tanks. The addition of carbohydrate significantly reduced the total ammonia‐N (TAN), nitrite‐N and nitrate‐N in water and it significantly increased the total heterotrophic bacteria (THB) population in the biofloc treatments. There was a significant difference in the final average body weight (8.49 ± 0.09 g) in the wheat flour treatment (BFT_W) than those treatment and control group of the shrimp. Survival of the shrimps was not affected by the treatments and ranged between 82.02% and 90.3%. The proximate and chemical composition of biofloc and proximate composition of the shrimp was significantly different between the biofloc treatments and control. Tintinids, ciliates, copepods, cyanobacteria and nematodes were identified in all the biofloc treatments, nematodes being the most dominant group of organisms in the biofloc. It could be concluded that the use of wheat flour (BFT_W) effectively enhanced the biofloc production and contributed towards better water quality which resulted in higher production of shrimp.     

Effects of different carbon sources addition on nutrition composition and extracellular enzymes activity of bioflocs,and digestive enzymes activity and growth performance of Litopenaeus vannamei in zero‐exchange culture tanks

A 35‐day feeding experiment was conducted to investigate the effects of different carbon sources addition on nutritional composition and extracellular enzymes activity of bioflocs, and digestive enzymes activity and growth performance of Litopenaeus vannamei juveniles (average 5.52 ± 0.21 g) in zero‐water exchange culture tanks. Molasses, corn flour and wheat bran were used as carbon sources and added into the tanks to promote the development of bioflocs during the experiment. During the entire experiment, good water quality and biofloc development were achieved under the addition of different carbon sources. At the end of the experiment, the proximate composition and extracellular enzymes activities of the collected bioflocs from seven biofloc groups were influenced by the addition of the different carbon sources. Meanwhile, the specific activities of protease, amylase, lipase and cellulase in the hepatopancreas, stomach and intestine of the shrimp showed differences among the seven biofloc groups, and most of them were significantly higher than those obtained in the control group (P < 0.05). There were differences in the performance (growth and FCR) of the shrimp among the seven biofloc groups, and all of them were significantly better than those obtained in the control group (P < 0.05). Based on the results of this study, 60% molasses + 20% corn flour + 20% wheat bran could be an appropriate formula of the addition of carbon sources for intensive culture of L. vannamei (mainly in terms of growth and FCR) in zero‐water exchange culture tanks.     

Proteome modifications of Pacific white shrimp (Litopenaeus vannamei) muscle under biofloc system

The objective of the study was to examine the effects of biofloc technology on the muscle proteome of Litopenaeus vannamei. Two biofloc treatments and one control were compared: biofloc‐based tanks under zero‐water exchange fed with 150 g/kg crude protein (BF15), or with 250 g/kg crude protein (BF25) diets, and clear water tanks with 50% of daily water exchange stocked with shrimp fed with similar amount of a 250 g/kg crude protein diet, referred to as control. The shrimp (5.28 ± 0.42 g) were divided into the 300‐L fibreglass tanks (water volume of 200 L) at a density of 35 shrimp per tank and were cultured for 35 days. The biofloc groups displayed better growth and survival compared to the control. The muscle tissue from the control and BF25 groups was subjected to proteomic analysis. Lactate dehydrogenase, enolase, arginine kinase, mitochondrial ATP synthase subunit alpha, mitochondrial ATPase inhibitor factor 1 precursor, serpin 3 and myeloid differentiation factor 88 had an increased abundance in the BF25 group, while myosin heavy chain type 1 and myosin heavy chain type 2 showed a decreased abundance. The results indicate that biofloc technology could alter the expression of proteins involved in structure, metabolism and immune status of cultured shrimp.     

Replacement of fishmeal by vegetable meal mix in the diets of Litopenaeus vannamei reared in low‐salinity biofloc system: effect on digestive enzymatic activity

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.     

Effect of different total suspended solids levels on a Litopenaeus vannamei (Boone, 1931) BFT culture system during biofloc formation

In a Biofloc Technology System (BFT), there is constant biofloc formation and suspended solids accumulation, leading to effects on water quality parameters that may affect the growth performance of cultured shrimp. This study aimed to analyse during biofloc formation the effect of different total suspended solids (TSS) levels on water quality and the growth performance of Litopenaeus vannamei shrimp in a BFT system. A 42‐day trial was conducted with treatments of three ranges of TSS: 100–300 mg L^?1 as low (TL), 300–600 as medium (TM) and 600–1000 as high (TH). The initial concentrations of 100 (TL), 300 (TM) and 600 mg L^?1 (TH) were achieved by fertilization before starting the experiment. Litopenaeus  vannamei juveniles with an average weight of 4.54 ± 1.19 g were stocked at a density of 372 shrimp m^?3. Physical and chemical water parameters and shrimp growth performance were analysed. After 6 weeks, TSS mean concentrations were 306.37, 532.43 and 745.2 mg L^?1 for, respectively, TL, TM and TH treatments. Significant differences (P < 0.05) were observed in TSS, settleable solids, pH, alkalinity and nitrite, especially between the TL and TH treatments. Similarly, differences (P < 0.05) were observed in the growth performance parameters, specifically final weight, survival, feed conversion and productivity. The water quality parameters at lower range of total suspended solids concentration (TL) treatment resulted in a better performance of L. vannamei in the BFT system. The maintenance at range of 100–300 mg L^?1 TSS is thus important to the success of shrimp culture.     

Higher nitrogen and phosphorus immobilization in bioflocs is associated with higher temperature and increased suspended solids in shrimp farming with biofloc technology

High stocking density aquaculture can result in major environmental impacts such as waste disposal with high organic matter. In order to overcome this issue, biofloc technology (BFT) has arisen as an alternative to lower effluent nutrient loading by promoting dense microbial communities that control water quality through the assimilation of inorganic nutrients. Given the central role of microorganisms in nutrients storage, the aim of this study was to evaluate the elemental composition of bioflocs and free‐living microorganisms and to determine which environmental factors are associated with the variation in their stoichiometric ratios (C:N:P) in shrimp farming systems. Samples were taken in marine shrimp farms, and the stoichiometric ratios from bioflocs and free‐living microorganisms were analysed, as well as physical and chemical water quality variables. The C:N ratios were lower, and N:P ratios were higher in the free‐living microorganisms than bioflocs. The C:P and N:P ratios of the biofloc were lower at higher temperature and total suspended solids (TSS). We concluded that the elemental composition of the bioflocs is richer in C and P and that systems with higher temperature and higher TSS have a greater ability to absorb and immobilize these elements in the bioflocs.     

Antioxidant effects of nanoencapsulated lipoic acid in tissues and on the immune condition in haemolymph of Pacific white shrimp Litopenaeus vannamei (Boone, 1931)

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.     

Effect of different water biofloc contents on the growth and immune response of gibel carp cultured in zero water exchange and no feed addition system

This study evaluated the growth and immune response of gibel carp (Carassius auratus gibelio) cultured under no feed addition biofloc technology (BFT) system at different total suspended solid (TSS) concentrations (10, 300, 600, 800 and 1,000 mg/L for group BF0‐NF, BF300‐NF, BF600‐NF, BF800‐NF and BF1000‐NF) for 30 days. The results demonstrated that bioflocs contained rich nutrients, and gibel carp eaten bioflocs showed higher weight gain, specific growth and survival. Digestive enzyme activities such as pepsin and amylase increased significantly in BF300/600/800/1000‐NF groups than those in BF0‐NF group. Antioxidant response including superoxide dismutase and total antioxidant capacity in serum and skin mucus was also enhanced significantly (p < .05). In addition, six immune‐related genes were examined by RT‐qPCR. Compared with BF0‐NF group, expression levels of immune genes intelectin (ITLN), dual specificity phosphatase 1 (DUSP 1), keratin 8 (KRT 8), myeloid‐specific‐peroxidase (MPO), c‐type lysozyme (c‐lys) and interleukin‐11 (IL‐11) were up‐regulated by 78.1‐, 23.9‐, 13.8‐, 138.8‐, 401.8‐ and 91.1‐fold, respectively. The highest expression values were observed at TSS of 600–800 mg/L. This study suggested that bioflocs can be uptaken by gibel carp as a food source, and have a potential to be used as a supplemental food for aquaculture.     

Dietary toxicity of manganese to shrimp and its accumulation in bioflocs

Bioflocs were produced in pilot‐scale biological reactors using acetate, glycerine or sugar as a carbon supplement while treating fish‐effluent waters. Bioflocs were dried and evaluated for nutritional quality and ingredient suitability. It was discovered that all bioflocs had excess manganese levels (9,500 mg kg^–1). Two trials were conducted as follows: (i) first feeding trial was a 6‐week experiment to determine the dietary toxicity of manganese to shrimp (Litopenaeus vannamei) in diets without bioflocs, and (ii) the second feeding trial (5 weeks) was conducted with the aforementioned bioflocs with elevated manganese content. In first feeding trial, experimental diets contained increasing concentrations of manganese: 260, 570, 1,100, 2,300, and 3,500 mg kg^–1. Levels of manganese above 570 mg kg^–1 significantly (p < .05) impacted shrimp growth. These results suggested that the maximum theoretical inclusion rate of these bioflocs into the diet was 100 g kg^–1. In second feeding trial, experimental diets contained the different sources of bioflocs: acetate biofloc 100 g kg^–1, glycerine biofloc 100 g kg^–1, sucrose biofloc 100 g kg^–1 replacing soybean meal and acetate biofloc 100 g kg^–1–FM (replaced fishmeal). Compared to the control, the glycerine biofloc 100 g kg^–1 and acetate biofloc 100 g kg^–1–FM significantly (p < .05) suppressed shrimp growth. The findings in this article demonstrate that careful considerations are needed in regard to potential elevated levels of trace elements in biofloc.