The Reuse of Water on the Culture of Pacific White Shrimp,Litopenaeus vannamei,in BFT System

The use of the same water over multiple culture cycles in a biofloc technology system can be highly beneficial. This study evaluated the effect of different levels of biofloc‐rich water on selected water quality indicators and on the productive performance of Pacific white shrimp, Litopenaeus vannamei, juveniles (3.5 g) stocked at 312 juveniles/m³ and cultured under conditions of no water exchange. The study was performed over a 30‐d period in an 800‐L tank system. A total of four biofloc enrichment levels (25, 50, 75, and 100%) and control (0%) were tested with three replicates each. Significant differences in nitrogen compounds were found between the biofloc‐enriched water and the zero‐enrichment treatment. No statistically significant differences among the biofloc‐enriched treatments were found in survival, final weight (8.25 g), and feed conversion ratio (FCR) (1.08). The shrimp raised in clear seawater (i.e., a 0% biofloc enrichment) were significantly smaller (7.37 g vs. 8.25 g) and showed a higher FCR (1.52 vs. 1.08) than the shrimp cultured in the biofloc‐rich water. Nevertheless, no differences in yields were found between treatments. The results of this study suggest that culture in biofloc‐enriched water produces higher levels of water quality and shrimp performance than culture in natural seawater.     

Biofloc technology with addition molasses as carbon sources applied to Litopenaeus vannamei juvenile production under the effects of different C/N ratios

The current study was conducted to evaluate the effects of increasing carbon to nitrogen (C/N) ratios on water quality, growth performance, and body composition of Litopenaeus vannamei juveniles. Shrimp with initial average weight of 2.50?±?0.3 g were cultivated for 35 days in 300-L tanks (160 L of water volume) with a density of 1 g per liter. The experiment was performed in five treatments with three replicates. One control group and four biofloc treatments with different C/N ratio were considered: C/N of 10 (CN10), 14 (CN14), 18 (CN18), and 22 (CN22). Shrimp were fed three times a day, and molasses just was added as a carbon sources to the biofloc treatments after each feeding. According to the results, the lowest amount of dissolved oxygen (5.33 mg L^?1) and pH (7.83) was observed in CN22 treatment, which showed a significant difference with other treatments (P?<?0.05). The highest level of total ammonia nitrogen (1.05 mg L^?1) and nitrite (mg L^?1) were recorded in control group, while the highest total density of heterotrophic bacteria was obtained in CN22 treatment. Growth performance parameters were at the highest level in the CN14 treatment, so the highest amount of final weight (6.88 g), biomass, and survival rate (94.79%) were observed in this treatment. The biochemical composition (protein, lipid, and ash) of the shrimp body and produced biofloc were affected by different C/N ratios, so these parameters were increased by rising of C/N ratio. In general, this study showed that the growth performance and body composition of Pacific white shrimp juveniles and water quality were suitable for rearing in biofloc system with C/N ratio of 14 than other treatments.

     

Growth performance and robustness of African Catfish Clarias gariepinus (Burchell) in biofloc‐based nursery production with different stocking densities

The aim of this research is to evaluate the effects of biofloc system application at different fish density on the nursery production performance and the robustness of African catfish Clarias gariepinus (Burchell) against Aeromonas hydrophila and salinity stress. An economic analysis was also performed to determine the most optimum fish density in biofloc‐based African catfish nursery production. African catfish with an average body weight of 0.96 ± 0.04 g and average body length of 4.20 ± 0.46 cm, respectively, were distributed in 12 units of circular plastic‐lined tanks (1,020 L). The experiment consisted of four treatments in triplicates, that is, a control without carbon source addition at a density of 4 fish/L, and three biofloc treatments at different densities, that is, BFT4 (4 fish/L), BFT6 (6 fish/L) and BFT8 (8 fish/L). Tapioca flour was used as the organic carbon source in biofloc systems and was added at an estimated C/N ratio of 10. Housing the fish in biofloc systems resulted in higher fish growth, more efficient feed utilization, higher fish robustness against A. hydrophila infection and salinity stress, as well as higher profitability of nursery production. Increasing the fish density resulted in higher mortality. However, higher number of fish produced and lower feed conversion ratio were observed in the treatments with higher density (6 and 8 fish/L). In conclusion, the application of biofloc technology at a density of 8 fish/L could be recommended to increase the production and profitability of African catfish nursery culture.     

Effect of biofloc technology (BFT) on the early postlarval stage of pink shrimp <Emphasis Type="Italic">Farfantepenaeus paulensis</Emphasis>: growth performance,floc composition and salinity stress tolerance

Biofloc rearing media provides a potential food source for shrimp reared in limited or zero water exchange systems. This culture system is environmentally friendly as it is based on limited water use and minimal effluent is released into the surrounding environment. In this study, we evaluated the survival, growth performance and salinity stress tolerance of pink shrimp Farfantepenaeus paulensis postlarvae reared from PL₁₀ to PL₂₅ in a biofloc technology limited water exchange system. PL (mean ± SD weight and length of 14 ± 10 mg and 8.10 ± 0.7 mm, respectively) were reared in nine 40-L plastic tanks with a stocking density of 10PL/L. Three culture treatments were applied (1) culture in the presence of bioflocs and commercial feed supply (FLOC + CF); (2) culture in the presence of biofloc without feed supply (FLOC) and (3) culture in clear water with feed supply (control). Final biomass and survival were significantly higher in FLOC + CF treatment than the control (P < 0.05), but did not differ from FLOC. PL reared in the FLOC + CF treatment achieved a significantly higher final weight, weight gain and length in comparison with the other two treatments (P < 0.05). No significant difference (P > 0.05) between treatments was found for salinity tolerance over 24 and 48 h durations. The proximate analysis of floc shown high levels of crude protein (30.4%), but low levels of crude lipids (0.5%). The continuous availability of bioflocs had a significant effect on growth and survival of F. paulensis postlarvae cultured in BFT nursery systems.     

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.     

Integration of substrate in biofloc based system: Effects on growth performance,water quality and immune responses in black tiger shrimp,Penaeus monodon culture

To evaluate effect of substrate integration in biofloc based system, a 52‐day growth experiment was conducted using black tiger shrimp, Penaeus monodon juveniles (3.32 ± 0.07 g). The factorial design consisted of floc, F (with or without) as first factor and substrate (bamboo mat, B; nylon mesh, N; and without substrate) as second factor. This resulted six treatments; F + B, F + N, F, B, N and a control without biofloc and substrate. Shrimps were stocked at 110 nos. m^–3 in Fibre Reinforced Plastic (FRP) tanks and, rice flour was used as carbon source in biofloc based treatments. Incorporation of nylon mesh and bamboo mat in biofloc system trapped 31.3%–38.6% and 8.5%–13.5% total suspended solids respectively and reduced bottom solid deposition. Among the substrate based groups, significantly better development of biofilm with higher microbial population noticed in F + B compared with nylon mesh. Similarly, significantly higher final growth (p < 0.01) was recorded in F + B system followed by F + N while no significant difference in body weight recorded among floc, F or substrate based groups (B, N). Biofloc and substrate integration (F + B and F + N) resulted significantly (p < 0.01) lower feed conversion ratio compared to control and floc. Incoporation of bamboo substrate in biofloc, (F + B) improved shrimp immune responses through higher hemocyte counts and prophenoloxidase activity compared to other treatments. The study revealed that integration of substrate in the biofloc system improved growth performance, FCR and immune parameters in shrimp by trapping the suspended biofloc particles, better water quality parameters, enhanced biofilm growth and provision of quality natural food.     

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.     

Evaluation of an alternative salt mixture to culture Pacific white shrimp (Litopenaeus vannamei) in inland aquaculture

Pacific white shrimp, Litopenaeus vannamei, exhibit a remarkable ability to tolerate low‐salinity environments, facilitating its culture far from coastal areas using various production systems at salinities less than 15 g/L. Recirculating aquaculture systems (RAS) and biofloc systems are usually operated using reconstituted sea salt (RSS), which is a considerable financial burden to commercial producers due to its higher price. Current study was carried out with the objective of testing the efficacy of a low‐cost salt solution to replace expensive RSS to grow shrimp under laboratory conditions. Low‐cost salt mixture (LCSM) was formulated to yield sodium, potassium, calcium and magnesium concentrations closely comparable to that of diluted seawater using agriculture grade sodium chloride, magnesium chloride, magnesium sulphate, potassium oxide, calcium chloride and sodium bicarbonate. Growth trials were conducted at three different salinities of 3, 6 and 15 g/L, incrementally replacing RSS with LCSM (0, 2.5, 25, 50, 75 and 100%) at four replicates per treatment. Twenty juvenile shrimp were reared for 42 days in 150 L polyethylene tanks. Ionic profile of water, ionic profile and osmolality of shrimp haemolymph were determined to justify growth and survival data through analysing ionic variations and osmoregulatory capacity of shrimp. At the conclusion, no significant differences were observed in survival, growth, osmoregulation and levels of cations in shrimp haemolymph between RSS and LCSM treatments at all salinities examined. Results reflect the potential use of LCSM to replace RSS which could be an excellent solution to bring down the cost of production in inland shrimp aquaculture.     

Effects of dietary protein and lipid levels on growth and energy productive value of pacific white shrimp,Litopenaeus vannamei,at different salinities

A 8‐week feeding experiment was conducted to evaluate the effect of different dietary protein and lipid levels on growth and energy productive value of juvenile Litopenaeus vannamei, at 30 and 2 ppt, respectively. Nine practical diets were formulated to contain three protein levels (380, 410 and 440 g kg^?1) and three lipid levels (60, 80 and 100 g kg^?1). Each diet was randomly fed to triplicate groups of 30 shrimps per tank (260 L). The effects of salinity and an interaction between dietary protein level and lipid level on growth and energy productive value of shrimp were observed under the experimental conditions of this study. At 30 ppt seawater, shrimp fed with 440 g kg^?1protein diets had significantly higher weight gain (WG) than those fed with 380 g kg^?1 protein diets at the same dietary lipid level, and the 60 g kg^?1 lipid group showed higher growth than 80 g kg^?1and 100 g kg^?1 lipid groups at the same dietary protein level. At 2 ppt seawater, the growth of shrimp was little affected by dietary protein treatments when shrimp fed the 80 and 100 g kg^?1 lipid, shrimp fed the 80 g kg^?1 lipid diets had only slightly higher growth than that fed 60and 100 g kg^?1 lipid diets when fed 380 and 410 g kg^?1 dietary protein diets. A significant effect of salinity on growth of shrimp was detected with the growth responses at 30 ppt > 2ppt (P < 0.05). Final body lipid content, body protein content and energy productive value of shrimp was significantly higher in animals exposed to 30 ppt than in shrimp held at 2 ppt.     

Tetrodotoxin accumulation conflicts with low salinity tolerance in juvenile tiger puffer Takifugu rubripes

We evaluated whether bearing tetrodotoxin (TTX) affects salinity stress in the juvenile tiger puffer Takifugu rubripes. Juveniles of hatchery-reared non-toxic T. rubripes [body weight (BW): 1.7?±?0.2 g, n?=?120] were divided into six tanks and acclimatized to salinity (8.5 ppt) that is equivalent to blood osmolality. Fish in three tanks were fed non-toxic diet, and those in the other three tanks were fed a TTX-containing diet (356 ng/g diet) three times a day until satiation. In each diet treatment, salinity of one tank was kept at 8.5 ppt, and the other two tanks were adjusted to either 1.7 or 34.0 ppt, and fish were reared for another 33 days. Then, we compared survival, growth, TTX accumulation, plasma osmolality, plasma cortisol, and glucose levels among treatments. We detected TTX only in the fish in the TTX-diet groups. Survival was highest at 8.5 ppt (70%) and lowest at 1.7 ppt in the TTX-diet group (20%). The BW was greater at 8.5 ppt, and plasma osmolality was significantly higher at 34.0 ppt than at any other salinities. Plasma cortisol level was significantly higher but glucose level was lower at 1.7 ppt. Possessing TTX at a low salinity may be lethal to tiger puffer juveniles.

     

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.     

Growth of Tiger Puffer, Takifugu rubripes, at Different Salinities

Two 12‐wk rearing experiments were conducted to examine the effect of rearing salinities of 10–35 ppt on the growth of 3‐ and 170‐g‐size tiger puffer, Takifugu rubripes. Fish were reared in a closed recirculation system without introducing fresh culture water at 23 C and were fed commercial pellet diet for tiger puffer twice or three times daily to apparent satiation each, almost everyday. Growth of 3‐g‐size fish seemed to increase with decreasing salinity; however, there were no significant differences in the specific growth rate and weight gain among treatments because of differences in initial body weight. Final body weight and length of fish reared at 10 ppt were significantly higher than those for fish reared at 30 ppt although initial sizes were similar. Differences were not found for the feed efficiency (FE) and daily feed consumption. Apparent relationships were not observed between salinity and blood characteristics or proximate compositions of muscle of the cultured fish. Differing from smaller fish, growth of 170‐g‐size fish tended to decrease with decreasing salinity from 30 to 10 ppt and with increasing salinity from 30 to 35 ppt. Similar trends for FE were observed.     

Growth and health performance of African catfish Clarias gariepinus (Burchell 1822) juvenile fed with graded levels of biofloc meal

The objective of the study was to evaluate the utilization of biofloc meal as a feed ingredient in enhancing the growth and health status of African catfish (Clarias gariepinus) juvenile. The study consisted of two experiments, that is digestibility and growth experiments. The digestibility of two biofloc meals produced with two different carbon sources, that is tapioca and molasses, were assessed in the digestibility experiment. Whereas the effect of four dietary treatments with different levels of biofloc meal, that is 0%, 5%, 10% and 20%, on the fish growth performance, feed utilization, immuno‐haematological response, antioxidant status and robustness against environmental stress were evaluated in the growth experiment. The results showed that the digestibility of dry matter, protein, lipid and phosphorus of biofloc grown using molasses as the carbon source were remarkably higher than that grown using tapioca (p < 0.05). The inclusion of biofloc meal in the diets at 10% and 20% resulted in higher feed intake, fish growth and final biomass and protein efficiency ratio, and lower feed conversion ratio (p < 0.05). Furthermore, the red blood cells counts, phagocytic, lysozyme activities and antioxidative capacity were significantly enhanced in the fish provided with diet containing 20% biofloc meal (p < 0.05).The fish survival following salinity stress test was higher in the treatments with biofloc meal at 10% and 20% inclusion levels. In conclusion, dietary inclusion of biofloc meal could improve the growth performance and health status of African catfish juvenile and an inclusion level of 20% could be recommended.     

Investigation of the Effects of Salinity and Dietary Protein Level on Growth and Survival of Pacific White Shrimp, Litopenaeus vannamei

It is presumed that in hypo‐ and hypersaline environments, shrimp’s requirements for some specific nutrients, such as protein, may differ from those known in the marine habitat; however, few investigations have been conducted in this area of study. In the present investigation, the effects of salinity and dietary protein level on the biological performance, tissue protein, and water content of Pacific white shrimp, Litopenaeus vannamei, were evaluated. In a 3 × 4 factorial experiment, juvenile shrimp with an average initial weight of 0.36 ± 0.02 g were exposed for 32 d to salinities of 2, 35, and 50 ppt and fed experimental diets with crude protein contents of 25, 30, 35, and 40%. A significant effect of salinity on growth of shrimp was detected, with the growth responses (final weight, weight gain) ranked in the order 2 ppt (3.87, 3.50 g) > 35 ppt (3.40, 3.04 g) > 50 ppt (2.84, 2.47 g). No effects of dietary protein level or an interaction between salinity and protein on growth of shrimp were observed under the experimental conditions of this study. Percent survival of shrimp fed the highest protein content (40%, survival of 74%) was, however, significantly lower than those of shrimp fed the other feeds (25, 30 and 35% protein, survival of 99, 91, and 94%, respectively), a result likely associated with the concentration of total ammonia nitrogen, which increased significantly at increasing protein levels. Final water content of whole shrimp was significantly lower in animals exposed to 50 ppt (70.8%) than in shrimp held at 2 (73.7%) and 35 ppt (72.3%). No effect of salinity, protein, or their interaction was observed on the protein content of whole shrimp. The results of the present study are in agreement with reports of superior and inferior growth of L. vannamei reared in hypo‐ and hypersaline environments, respectively, as compared to what is generally observed in seawater.     

Lethal Low Dissolved Oxygen Concentrations for Postlarvae and Early Juvenile Penaeus setiferus at Different Salinities and pH

Abstract This study was undertaken to determine the effect of salinity and pH on tolerance to low dissolved oxygen concentration in postlarval (PL 12; 18 mg wet weight) and early juvenile (720 mg wet weight) Peneaus setiferus . Lethal levels of dissolved oxygen were determined in animals at four combinations of salinity and pH (36 and 15 ppt salinity and pH 6 and 8). For postlarvae, the 48-h LC50 for dissolved oxygen was 1.27 mgO₂/L at 15 ppt and pH8, and was significantly lower than that obtained in the other combinations of salinity and pH (P < 0.05). For juveniles, the 72-h LC50 was 1.16 mg1L at 15 ppt and pH 8, and was significantly lower than that obtained in the other combinations of salinity and pH (P < 0.05). A significant interaction between salinity and pH was observed. These results suggest that the intensive culture of P. setiferus may be conducted at moderate salinity, where shrimp appear to be more tolerant of low concentrations of oxygen than at higher salinities.     

投喂不同饵料对长薄鳅生长的影响

在水温18.6～21.6℃条件下,将初始体质量为(3.91±0.22) g的长薄鳅幼鱼随机分为5组,每组3个重复,每个重复10尾鱼,饲养在圆形玻纤缸(直径1 m、高0.8 m)中,分别投喂刀额新对虾、鳙鱼、配合饲料(粗蛋白≥46.0%)、虾+饲料、鱼+饲料5种饵料,以筛选适宜于长薄鳅幼鱼的适宜饵料投喂模式。75 d的饲养结果表明,不同投喂模式对长薄鳅的存活率无显著性影响(P>0.05),而对长薄鳅的生长影响显著(P<0.05)。试验结果表明,虾组、鱼组、饲料组、鱼+饲料组的长薄鳅最终体质量无显著性差异(P>0.05),但虾+饲料组最终体质量和体质量特定生长率显著高于其他4组(P<0.05),依次为虾+饲料组>饲料组>虾组>鱼组、鱼+饲料组。5个试验组鱼的体长特定生长率无显著性差异(P>0.05),依次为虾+饲料组>虾组>饲料组、鱼+饲料组>鱼组。试验结束时,各试验组鱼的生长离散均有所升高,生长离散变化依次为鱼组>鱼+饲料组>饲料组>虾组>虾+饲料组。各试验组长薄鳅的的摄食率差异显著(P<0.05),摄食率依次为鱼组>虾组>鱼+饲料组>虾+饲料组>饲料组;虾组和鱼组的饵料系数无显著性差异(P>0.05),但显著高于其他3组(P<0.05),其他3组间无显著性差异(P>0.05)。不同投喂模式下长薄鳅幼鱼的生长系数b值均小于3,呈负异速生长,但虾+饲料组的长薄鳅幼鱼生长系数b值最大。试验过程中各组鱼的肥满度均下降。研究结果显示,在本试验的不同饵料投喂模式中,投喂虾+饲料更利于长薄鳅的摄食和生长。     

Interaction of Salinity and Feed Protein Level on Growth of Penaeus vannamel

An intensive 42-day growth trial conducted in ourdoor tanks with Penaeus vannamei (stocking weight of 5.3g, density of 30/m²) indicated that there was a significant interaction between salinity and protein level of the feed. In 46 ppt water, shrimp fed feed containing 45% protein grew faster (2.98%/day) than shrimp fed 35 and 25% protein rations (2.84 and 2.73%/day, respectively). At 12 ppt, growth of shrimp fed 35% feed was faster (3.23%/day) than growth of shrimp fed 25% protein feed (3.07%/day). Shrimp fed the 45% protein feed did not grow faster 3.14%/day) than shrimp fed 35 an 25% protein feeds. At each protein level, growth at 12 ppt was greater than at 46ppt. Survival was not affeted by either salinity or feed protein level and averaged 86%. Results indicate that nutritional requirements vary with culture salinity and suggest that use of higher protein feeds under hypersaline culture conditions may produce higher yields.     

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.