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Bacterial inorganic nitrogen control using carbon:nitrogen ratio (C:N) manipulation is a tool for aquaculture systems. The present study assessed the hatchery performance of Litopenaeus vannamei between the mysis 1 and postlarvae 5 stages in a zero-exchange biofloc system under different C:N fertilization levels (10:1, 12.5:1 and 15:1) with dextrose. Water quality, performance parameters and water microbiology were compared among treatments. The mean values of the evaluated water quality parameters were appropriate for this production stage. Fertilization with dextrose efficiently controlled ammonia levels, which did not reach the average concentrations considered toxic for the species. In the 10:1 C:N ratio treatment, the levels of ammonia started to increase early and showed significantly higher levels from the third to the last experimental day. There was no difference among groups in means of survival (>76%) and dry weight (0.26 mg) of L. vannamei production parameters and water quality were maintained without water exchange using a biofloc system supplemented with dextrose. Therefore, the use of biofloc systems without water exchange with dextrose as a carbon source in C:N ratios of 10:1, 12.5:1 and 15:1 results in both adequate production indexes and water quality during the misis 1 to post-larvae 5 hatchery phases of L. vannamei. However, the ratios of 12.5:1 and 15:1 keep lower levels of ammonia. 相似文献
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Lucas Pellegrin Lilian Fiori Nitz Daniel de S Britto Pinto Carlos Eduardo Copatti Wilson Wasielesky Luciano Garcia 《Aquaculture Research》2022,53(1):276-284
This study determined the effects of total suspended solids (TSS) on pacu (Piaractus mesopotamicus) culture in a biofloc technology (BFT) system by performing two experiments. Experiment 1 evaluated the LC50-96 h of pacu at seven TSS levels (0, 1500, 3000, 4000, 5000, 6000 and 7000 mg L?1). Experiment 2 evaluated haematological variables (glucose, pH, haematocrit, haemoglobin, erythrocytes and haematimetric indices) in juveniles exposed to five different sublethal TSS concentrations (0, 250, 500, 750 and 1000 mg L?1) for 5 days. Treatments below 5000 mg L?1 did not cause mortality, and the LC50-96 h of TSS was estimated at 5477 mg L?1. The TSS concentrations that caused mortality in pacu juveniles were extremely high and rarely maintained in culture systems. Exposure to high TSS concentrations (mainly 750 and 1000 mg L?1) increased blood glucose, pH, heamatocrit, erythrocytes, haemoglobin values and haematimetric indices on the first day. On the fifth day, most of the evaluated parameters stabilized at different TSS concentrations. In conclusion, pacu exposed to high TSS concentrations for short periods may undergo physiological changes, and TSS concentrations below 250 mg L?1 are recommended for its culture in a BFT system. 相似文献
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The present study investigated the effectiveness of biochar as a water quality control agent and an alternative carbon source in a tilapia-based biofloc technology (BFT) system. Water quality parameters were measured following standard procedures (APHA, 1998) and fish physiological indices were measured using designated ELISA kits. Data was analyzed using repeated measures ANOVA and one-way ANOVA. Two biochar treatments were employed i.e. B; only biochar, GB; biochar + glucose, while for the control (G) only glucose was added. Tilapia fingerlings were cultured for approximately 10 weeks with no water exchange. Significant reduction (p < 0.05) in dissolved oxygen (DO) level was observed in group G (5.99 ± 0.10 mg/L) compared to B (6.66 ± 0.12 mg/L) and GB (6.53 ± 0.56 mg/L). Notably, concentrations of total suspended solids (TSS) were signficantly lower in the biochar treatments (B and GB) compared to the control (G). Additionally, alkalinity was significantly higher in G (156.47 ± 5.17 mg/L) compared to B (137.92 ± 3.83 mg/L) and GB (146.44 ± 3.87 mg/L). Levels of NO3- and total nitrogen (TN) were significantly higher in group B compared to G and GB. Also, significant difference was observed in PO43- levels between B (30.81 ± 2.28 mg/L) and GB (22.70 ± 1.84 mg/L). The dynamics of the water quality parameters revealed that heterotrophic assimilation and nitrification were active in maintaining the water quality. Overall, the result showed no significant differences (p > 0.05) in all the fish growth parameters. Urea nitrogen measured in the fish was significantly lower in B (3.85 ± 0.32 mmol/L) compared to G (5.40 ± 0.39 mmol/L) and GB (5.53 ± 0.39 mmol/L). Generally, there were no notable detrimental effects of biochar application on fish growth and physiological performance. 相似文献
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The aim of this study was to evaluate the effect of two methodologies of carbohydrate fertilization on the volume and characteristics of effluent from intensive biofloc shrimp cultivation. Six fiberglass circular tanks (50 m2 each) were divided into two treatments. In the treatment called continuous (CONT), the tanks received daily molasses fertilization throughout the entire rearing period. In the treatment named initial (INI), molasses was used only in the early weeks of cultivation. Juvenile Litopenaeus vannamei (0.87 ± 0.10 g) were stocked at a density of 180 animals m−2 and cultured during 12 weeks until they reached an average weight of 12 g. The tanks were operated with no water exchange and the total suspended solids concentration were kept between 300 and 400 mg L−1 using settling chambers. The sludge produced and the wastewater at harvest were quantified and their characteristics were determined. The production of TSS in the CONT treatment was higher (0.25 kg of solids per kg of applied feed) than in the INI treatment (0.16 kg kg−1) (P < 0.05). The analysis of the sludge revealed a high amount of volatile solids in both treatments, between 636 and 702 g kg−1. However, due to the elevated sludge nitrogen content, the carbon to nitrogen (C:N) ratio was low, with values of 6.4 ± 1.4 and 7.5 ± 1.6 for INI and CONT respectively. The BOD:TSS ratio was also low in both treatments, but the INI showed lower values (10.3 ± 0.6%) than the CONT (14.9 ± 0.0%) (P < 0.05). Both fertilization strategies were able to modify the characteristics of sludge produced during cultivation. Moreover, the high nitrogen and sulfate content of the sludge in both treatments indicated that it may be difficult to use an anaerobic digestion process to treat sludge. In the INI treatment tanks, the sludge is partially stabilized, while in the CONT there was a greater need for stabilization. 相似文献
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A 13-day nursery trial was conducted to evaluate the performance of young Litopenaeus vannamei post-larvae (from PL6 to PL18) reared in both biofloc and microalgae-based systems at a stocking density of 67 PLs L−1. The effects of different concentrations of total suspended solids (TSS) on PL performance were also evaluated. One experimental group was reared in a conventional microalgae-based system with daily water exchange and daily addition of microalgae (herein called microalgae treatment). The other two experimental groups were reared using biofloc technology (BFT) with daily dextrose addition and no water exchange, but in the “Biofloc-500” treatment, TSS were maintained at around 500 mg L−1, while in the “Biofloc-700” treatment, TSS were maintained at around 700 mg L−1. Water quality variables remained within the appropriate range for larval culture. In microalgae treatment, ammonia control was likely associated with its assimilation into microalgae biomass and daily water exchange. In biofloc tanks, however, the addition of dextrose stimulated the production of bacterial biomass from ammonia. This system required only 12.9% of the water used by the microalgae treatment since water was not exchanged during the culture. The nursery of young PLs resulted in similar (P > 0.05) performance in all treatments: survival >94%, PL length ∼ 11.5 mm, and PL dry weight ∼ 1.2 mg. In addition, the salinity stress test (>90.0%) was not significantly different among treatments. Our results indicate that BFT can be as effective as the microalgae-based system for the nursery of young L. vannamei post-larvae. We also found that post-larvae performance was similar (P > 0.05) between biofloc treatments, indicating that organisms can tolerate environments with large quantities of solids. 相似文献
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Diego Moreira de Souza Sabrina Medeiros Suita Fabio Pereira Leivas Leite Luis Alberto Romano Wilson Wasielesky Eduardo Luis Cupertino Ballester 《Aquaculture Research》2012,43(12):1828-1837
The present work evaluated the use of probiotics during the nursery rearing of the pink shrimp Farfantepenaeus brasiliensis, in a zero exchange aerobic heterotrophic culture system during 30 days. Three replicate tanks were randomly assigned to the following treatments: (1) Bacillus spp. mixture (Sanolife Pro‐‐W®), (2) Bacillus sp., Enterococcus sp., Lactobacillus spp. mixture (Biomin Start‐grow®), (3) Bacillus cereus var. toyoi and (4) control treatment (without probiotic addition). Bacteriological analysis monitored the abundance of presumptive Vibrio spp. in the water of experimental tanks. For the immunological analysis, shrimp haemolymph was collected to determine the granular haemocyte count and total protein concentration. Results showed that mean final weight and specific growth rate of shrimp in the probiotic treatments were significantly higher. Furthermore, shrimp reared in the probiotic treatments showed higher levels of total protein and granular haemocyte. The bacteriological analysis showed that the concentration of Vibrio spp. measured in probiotic treatment tanks was lower than that recorded in the control tanks. 相似文献
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为研究生物絮凝养殖条件下吉富罗非鱼的消化能力和免疫能力,采用室内循环水养殖系统(对照组)和生物絮凝养殖系统(实验组)饲养吉富罗非鱼(24.17±2.49)g 59 d。结果显示,与对照组相比,实验组水体中总氨氮(TAN)和亚硝态氮(NO-2-N)浓度均显著高于对照组,分别为(20.48±14.66)和(33.77±34.57)mg/L。但实验结束时实验组终末密度(FD)高达36.89 kg/m3,终末质量(FIW)、增重率(WGR)和特定生长率(SGR)均高于对照组(P0.05),饵料系数(FCR)比对照组降低18.7%(P0.05)。实验组饲料氮利用率为57.97%,显著高于对照组(49.51%)。实验组和对照组中罗非鱼的胃蛋白酶、胃脂肪酶、肠蛋白酶和肠脂肪酶活性无显著差异。除肝胰脏总超氧化物歧化酶(T-SOD)活性显著低于对照组外,实验组血清、肝胰脏和头肾的T-SOD、溶菌酶(LZM)、碱性磷酸酶活力(AKP)活性较对照组无差异(P0.05)。 相似文献
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Anselmo Miranda‐Baeza Mariela Nolasco‐Lpez Martha Elisa Rivas‐Vega Jos Alberto Huerta‐Rbago Luis Rafael Martínez‐Crdova Marcel Martínez‐Porchas 《Aquaculture Research》2020,51(1):255-264
The aim of this study was to evaluate the short‐term effect of probiotic inoculation on the abundance of heterotrophic and ammonia‐oxidizing bacteria in mature biofloc, as well as on total suspended solids (TSS), chlorophyll‐a and nitrogenous compounds in water. A completely randomized design consisting of five treatments (three commercial probiotics, one native consortia and one control) was performed. At the beginning of the experiment (day 1), each treatment was inoculated with the respective probiotic: PondPlus® (PP), Efinol® PT (EF) and Epicin® ponds (EP), native consortia UE, whereas the control was not inoculated. Water parameters and bacterial abundance were evaluated at 0, 2, 4, 6 and 8 days. The addition of probiotics, either native or commercial, did not show any significant effect on the TSS, Chl‐a and colony‐forming unit (CFU) of heterotrophic bacteria when they were added to the systems containing mature biofloc. A significant increase in ammonium oxidizing bacteria was registered with the probiotics PP and EP, although the levels of total ammonia nitrogen, NO3‐N and NO2‐N were statistically similar among all treatments. Modifications on most of the parameters measured were associated with the factor of time, rather than the inclusion of probiotics. Results suggest that the bacterial conglomerates in mature stage contain well‐established bacterial communities that are difficult to be affected by the addition of probiotics. 相似文献
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Esmeralda Chamorro Legarda Mateus Aranha Martins Patriula Kaliana Moreira Pereira Ramon Felipe Siqueira Carneiro Isabela Claudiana Pinheiro Walter Quadros Seiffert Claudia Machado Marco Antonio de Lorenzo Felipe do Nascimento Vieira 《Aquaculture Research》2020,51(9):3571-3581
This work compared the effects of different densities of Mugil curema integrated in the rearing of Litopenaeus vannamei in a biofloc system on the yield and ecological performance of the system. For that, an experiment lasting 55 days was conducted. Four groups were evaluated as follows: (a) T0: shrimp reared without mullet, (b) T10: shrimp reared with 22 fish per tank, (c) T20: shrimp reared with 43 fish per tank, and (d) T30: shrimp reared with 65 fish per tank, each treatment with four replicates. The sludge:biomass ratio was higher in the T0 treatment, while the T10–T20 treatments were more efficient, producing more biomass and less sludge. The use of water was 17% more efficient in all treatments with mullet. Mullet survival was higher in the T10 and T20 treatments (mean: 84 ± 8%) than in the T30 (61 ± 5%) treatment. The fish final biomass and yield limits of the system were 0.37 kg and 3.7 kg/m3 respectively. Finally, there was no increase in the total nitrogen output of the system up to the T10 density. In conclusion, it is possible to integrate mullet up to 3.7 kg/m3, increasing the yield in 20% and decreasing water use. 相似文献
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