Total Nitrite Levels Research Articles

Anti-viral Effects of Pavetta indica Methanolic Extract and Acyclovir on Behavioral and Biochemical Parameters in Streptozotocin-induced Alzheimer's Disease in Rats.

Alzheimer's disease is a neurological dysfunction of the brain caused by neurodegeneration and oxidative stress. Some viruses, such as herpes viruses, HSV-1, and HSV-2, are causative agents of Alzheimer's disease and result in β-amyloid peptide and tau protein accumulation in the brain. Some antiviral drugs, such as valacyclovir, acyclovir, and foscarnet, reduce amyloid-beta and P-tau. Pavetta indica leaves are also reported for their antiviral properties. The current study aimed to find out the significance of using Pavetta indica methanolic extract and acyclovir against Alzheimer's disease induced by streptozotocin. Wistar rats received acyclovir and Pavetta indica methanolic extract orally at different dose ranges (50, 150, 450 mg/kg) and (125, 250, 500 mg/kg), respectively. The standard therapy, Rivastigmine (2 mg/kg), was given orally. Intracerebroventricular-streptozotocin produced significant alternations in behavioral assessments, including locomotor activity test, Morris water maze test, and elevated plus maze test. Moreover, intracerebroventricular-streptozotocin ameliorated the antioxidant defense activity by decreasing levels of catalase, superoxide dismutase, and reduced glutathione while enhancing the oxidative stress markers, including malondialdehyde, and total nitrite levels. Finally, the main findings showed that intracerebroventricular-streptozotocin significantly increased the inflammatory marker, tumor necrosis factor-α, and disturbed neurotransmitter mediators, including levels of acetylcholinesterase, glutamate, and γ-amino butyric acid. In a dose-dependent manner, acyclovir and Pavetta indica methanolic extract treatments abrogated the streptozotocin-induced behavioral and neurological abnormalities in rats. The potential therapeutic effects of PIME and acyclovir administration in intracerebroventricular-streptozotocin-treated rats may be attributed to its potential antiviral, antioxidant, and anti-inflammatory effects. The current study suggests that Pavetta indica methanolic extract and acyclovir are promising therapeutic targets against Alzheimer's disease.

Effects of settleable versus unsettled biofloc removal strategy on aquaculture system performance and microbial community

The management of biofloc quality and quantity is critical in biofloc-based aquaculture systems. This research explores the effects of the selective removal of settleable and unsettled bioflocs on biofloc quality, fish growth, nitrogen transformation and bacterial community dynamics in these systems. Nile tilapia (Oreochromis niloticus) was reared at a density of 2.7 kg/m3 in nine 250-L conical breeding tanks over a 47-day period. Systems where unsettled bioflocs were removed outperformed others, achieving a 26 % higher weight gain in tilapia and maintaining more stable and lower levels of total ammonia (0.45 mg-N/L) and nitrite (0.35 mg-N/L). Additionally, these systems maintained a healthier bacterial environment, evidenced by a 27 % increase in beneficial bacterial populations and a 30 % reduction in harmful bacteria. Conversely, tanks removing settleable bioflocs showed a 19 % higher microbial diversity but experienced fluctuations in nitrogen levels. Notably, the intestinal bacterial community in tilapia from the unsettled biofloc group closely mirrored (87 % similarity) that of their corresponding bioflocs, with significant pathogenic symptoms observed (p < 0.05). These findings suggest the importance of implementing precise biofloc management strategies, highlighting that the selective removal of unsettled bioflocs enhances fish growth and improves overall system health. Future research should explore the mechanistic relationships between settleable and unsettled bioflocs to refine management strategies that bolster sustainability and economic benefits.

Antidepressant potential of β-caryophyllene in maternal separation-induced depression-like in mice: A focus on oxidative stress and nitrite levels

BackgroundMajor depressive disorder is prevalent across different societies, affecting individuals from various cultural and socioeconomic backgrounds. Dysregulation of the nitric oxide (NO) pathway and increased oxidative stress have been implicated as contributing factors. PurposeThis study aimed to explore the antidepressant potential of β-caryophyllene in a mouse model subjected to maternal separation stress, with a focus on its effects on oxidative stress and nitrite levels. Study DesignThe research involved 40 male mice, which were divided into five groups. MethodsThe control group received 1 ml/kg of normal saline, while the maternal separation (MS) groups were administered normal saline in conjunction with β-caryophyllene at doses of 10, 20, and 50 mg/kg. Various behavioral tests, including the open field test (OFT), forced swimming test (FST), and splash test, were employed to assess the impact of β-caryophyllene. Additionally, measurements of total antioxidant capacity (TAC), malondialdehyde (MDA), and nitrite levels in the hippocampus were conducted. ResultsThe findings demonstrated that maternal separation stress induced depressive-like behaviors in mice, as evidenced by increased immobility time in the FST and decreased grooming behavior in the splash test. Furthermore, MS was associated with elevated MDA and nitrite levels and reduced TAC in the hippocampus. However, administration of β-caryophyllene increased grooming activity in the splash test and decreased immobility time in the FST. Additionally, β-caryophyllene exhibited antioxidant properties, lowering MDA and nitrite levels while enhancing TAC in the hippocampus. ConclusionThese results suggest that β-caryophyllene may possess antidepressant-like effects in mice subjected to maternal separation, likely due to its antioxidant actions in the hippocampus.

Neuroimmune response and oxidative stress in the prefrontal cortex mediate seizure susceptibility in experimental colitis in male mice.

Inflammatory bowel disease (IBD) is a chronic gastrointestinal disorder. Oxidative stress and inflammatory responses have a vital role in the pathophysiology of IBD as well as seizure. IBD is associated with extraintestinal manifestations. This study aimed to explore the relationship between colitis and susceptibility to seizures, with a focus on the roles of neuroinflammation and oxidative stress in acetic acid-induced colitis in mice. Forty male Naval Medical Research Institute mice were divided into four groups: control, colitis, pentylenetetrazole (PTZ), and colitis + PTZ. Colitis was induced by intrarectal administration of acetic acid, and seizures were induced by intravenous injection of PTZ 7 days postcolitis induction. Following the measurement of latency to seizure, the mice were killed, and their colons and prefrontal cortex (PFC) were dissected. Gene expression of inflammatory markers including interleukin-1β, tumor necrosis factor-alpha, NOD-like receptor protein 3, and toll-like receptor 4, as well as total antioxidant capacity (TAC), malondialdehyde (MDA), and nitrite levels were measured in the colon and PFC. Histopathological evaluations were performed on the colon samples. Data were analyzed by t-test or one-way variance analysis. Colitis decreased latency to seizure, increased gene expression of inflammatory markers, and altered levels of MDA, nitrite, and TAC in both the colon and PFC. Simultaneous induction of colitis and seizure exacerbated the neuroimmune response and oxidative stress in the PFC and colon. Results concluded that neuroinflammation and oxidative stress in the PFC at least partially mediate the comorbid decrease in seizure latency in mice with colitis.

The Interplay between Nitrosative Stress, Inflammation, and Antioxidant Defense in Patients with Lichen Planus.

Lichen planus (LP) is a chronic inflammatory skin disease of unelucidated etiology. LP immunopathogenesis is mainly governed by cytotoxic T lymphocytes that mediate an immune response in basal keratinocytes, which may transform into a reservoir of antigens able to initiate an autoimmune reaction. However, other pathogenic pathways complement these mechanisms. Recent studies highlight the involvement of nitrosative stress in the pathogenesis of chronic inflammatory skin diseases. Current data on its role in the pathogenesis of LP are scarce. In this article, we investigated nitrosative stress in 40 cutaneous LP (CLP) patients compared to 40 healthy subjects using serum markers including nitrosative stress markers-direct nitrite, total nitrite, nitrate and symmetric dimethylarginine (SDMA), total antioxidant status (TAS), and hsCRP, a marker of inflammation, and analyzed the relationship between nitrosative stress, antioxidant defense, and inflammation to offer new insights into the role of the NO pathway in LP pathogenesis. We identified significantly higher serum levels of direct nitrite, total nitrite, nitrate, SDMA and hsCRP, and significantly lower levels of TAS in CLP patients versus controls. There were significant negative correlations between the serum levels of TAS and significantl positive correlations between the serum levels of hsCRP and the analyzed nitrosative stress markers in patients with CLP. Our results indicate an increased level of nitrosative stress in LP patients that correlates with a pro-inflammatory status and altered antioxidant defense.

Anethole as a promising antidepressant for maternal separation stress in mice by modulating oxidative stress and nitrite imbalance

The occurrence of major depressive disorder is widespread and can be observed in individuals belonging to all societies. It has been suggested that changes in the NO pathway and heightened oxidative stress may play a role in developing this condition. Anethole is a diterpene aromatic compound found in the Umbelliferae, Apiaceae, and Schisandraceae families. It has potential pharmacological effects like antioxidant, anxiolytic, analgesic, anti-inflammatory, antidiabetic, gastroprotective, anticancer, estrogenic, and antimicrobial activities. This study aimed to investigate the potential antidepressant properties of Anethole in a mouse model experiencing maternal separation stress while also examining its impact on oxidative stress and nitrite levels. The research involved the participation of 40 male NMRI mice, separated into five distinct groups to conduct the study. The control group was administered 1 ml/kg of normal saline, while the MS groups were given normal saline and Anethole at 10, 50, and 100 mg/kg doses. The study comprised various behavioural tests, including the open field test (OFT), forced swimming test (FST), and splash test, to assess the effects of Anethole on the mice. In addition to the behavioural tests, measurements were taken to evaluate the total antioxidant capacity (TAC), malondialdehyde (MDA), and nitrite levels in the hippocampus of the mice. According to the findings, maternal separation stress (MS) led to depressive-like conduct in mice, including a rise in immobility duration during the FST and a reduction in the duration of grooming behaviour in the splash test. Additionally, the results indicated that MS correlated with an increase in the levels of MDA and nitrite and a reduction in the TAC in the hippocampus. However, the administration of Anethole resulted in an increase in grooming activity time during the splash test and a decrease in immobility time during the FST. Anethole also exhibited antioxidant characteristics, as demonstrated by its ability to lower MDA and nitrite levels while increasing the TAC in the hippocampus. The results suggest that Anethole may have an antidepressant-like impact on mice separated from their mothers, likely partly due to its antioxidant properties in the hippocampus.

The therapeutic potential of Melissa officinalis L. hydroalcoholic extract and rosmarinic acid in a rat asthmatic model: A study on anti-inflammatory and antioxidant effects.

The article studies how Melissa officinalis L. extract and rosmarinic acid (RA) affect lung inflammation, pathology, and oxidative stress in rats with ovalbumin-induced asthma. Asthma was induced in rats using ovalbumin injection and inhalation. The study assessed lung inflammation, pathological changes, and oxidative stress in control, untreated asthmatic rats and three treatment groups. These groups received M. officinalis extract (50, 100, 200 mg/kg), RA (0.5, 1, 2 mg/kg), or dexamethasone (Dex) 1 mg/kg. In the sensitized group, white blood cell counts, malondialdehyde, and nitrite levels increased significantly, while thiol levels and the activity of superoxide dismutase and catalase decreased (p<0.001). However, all treatment groups with the extract, RA, and Dex showed a significant reduction in total white blood cells, eosinophils, monocytes, malondialdehyde, and nitrite levels compared to the asthma group (p<0.001 in all groups). Thiol levels and catalase and superoxide dismutase activity were significantly higher in all treated groups with RA and high extract doses (p<0.001). Lung pathological changes were also significantly less severe in the treated groups with dexamethasone, plant extract, and RA compared to the asthma group (p<0.05 to p<0.001). This study showed that M. officinalis and RA have antioxidant and anti-inflammatory effects in an animal asthma model, suggesting their potential for treating asthma symptoms.

Umbelliprenin via increase in the MECP2 and attenuation of oxidative stress mitigates the autistic-like behaviors in mouse model of maternal separation stress.

Introduction: Autism spectrum disorder (ASD) is a complex neurodevelopmental condition. Maternal separation (MS) stress is an early-life stress factor associated with behaviors resembling Autism. Both MECP2 and oxidative stress are implicated in the pathophysiology of Autism. Umbelliprenin (UMB) is a coumarin compound with various pharmacological properties. Our study aimed to investigate the potential effects of UMB in mitigating autistic-like behaviors in a mouse model subjected to MS stress, focusing on probable alterations in MECP2 gene expression in the hippocampus. Methods: MS paradigm was performed, and mice were treated with saline or UMB. Behavioral tests consisting of the three-chamber test (evaluating social interaction), shuttle box (assessing passive avoidance memory), elevated plus-maze (measuring anxiety-like behaviors), and marble-burying test (evaluating repetitive behaviors) were conducted. Gene expression of MECP2 and measurements of total antioxidant capacity (TAC), nitrite level, and malondialdehyde (MDA) level were assessed in the hippocampus. Results: The findings demonstrated that MS-induced behaviors resembling Autism, accompanied by decreased MECP2 gene expression, elevated nitrite, MDA levels, and reduced TAC in the hippocampus. UMB mitigated these autistic-like behaviors induced by MS and attenuated the adverse effects of MS on oxidative stress and MECP2 gene expression in the hippocampus. Conclusion: In conclusion, UMB likely attenuated autistic-like behaviors caused by MS stress, probably, through the reduction of oxidative stress and an increase in MECP2 gene expression.

Growth Performance of Critically Endangered Hypselobarbus pulchellus in Biofloc Systems with Various C/N Ratios

Background: Biofloc technology relies on adding a carbon source to maintain optimal carbon to nitrogen ratio for transforming the waste into microbial biomass that aquatic animals can use. In the present study, the growth performance of the critically endangered Hypselobarbus pulchellus in biofloc-based seed rearing with different Carbon to Nitrogen ratio was studied. Methods: Healthy early fry (0.01 g) was randomly stocked into 15 circular FRP tanks (1000 L) at a density of 100 individuals/m3 and reared for 90 days. The carbon to nitrogen ratios of 5:1(CN5), 10:1(CN10), 15:1(CN15) and 20:1(CN20) were maintained using jaggery without considering carbon content derived from the feed and the control group received no additional source of carbon. Result: The results indicated that H. pulchellus had better growth performance in biofloc systems having higher C/N ratios. The highest weight gain (0.48±0.01 g) and weight gain percentage (3931.15±120.68%) and specific growth rate (4.11±0.03% per day) were found in the CN10 group (P less than 0.05), followed by CN15 and CN20, while the control group values were lowest. In terms of survival, all treatments had high survival rates ranging from 92% to 94.67%, with no significant variations (P greater than 0.05). The CN10, CN15 and CN20 treatments had significantly higher amylase, protease and lipase activities than control (P less than 0.05). Moreover, the immunological and antioxidant activity increased with CN ratios. The CN10, CN15 and CN20 groups had significantly lower total ammonia nitrogen, nitrite and nitrate levels than control group (P less than 0.05). Overall, this study suggests that C/N ratios of 10:1 to 20:1 are optimal for rearing H. pulchellus fingerlings from early fry, with 10:1 presenting the best growth results.

Effects of environmentally relevant concentrations of micro(nano)plastics on aquatic microorganisms: Changes in potential function but not in overall composition

Micro(nano)plastics (MNPs) are a growing problem as persistent environmental pollutants. Here, we investigated the impact of MNPs on microorganisms in aquatic microbial floc exposed to NPs (80 ​nm) and MPs (8 ​μm) for 35 days. Water quality indicators were tested weekly and microbiological analyses were conducted on Day 7 and 28 after exposure. The results showed that there were significant differences in the levels of total ammonia nitrogen or nitrite between the MNPs groups and the control group, spanning from Day 7 to Day 28. For the microbial response, microbial community richness in the NPs and MPs groups were significantly increased at Day 7. Functional prediction showed that the relative abundances of bacteria associated with the “Forms Biofilms”, “Potentially Pathogenic”, “Plastic Degradation” and nitrogen cycle processes were significantly different after MNPs exposure. The results suggest that MNPs had no significant effect on the microbial diversity of mature microbial flocs. Findings suggest MPs could cause an increase in the relative abundance of potentially pathogenic bacteria, while NPs do not. In addition, stress associated with MNPs affected the nitrogen cycle of microorganisms, and NPs exerted greater impacts than MPs. Findings from this study further our understanding of the impact of MNPs at environmentally relevant concentrations on microorganisms in aquatic ecosystems.

Mechanistic Protective Effect of Cilostazol in Cisplatin-Induced Testicular Damage via Regulation of Oxidative Stress and TNF-α/NF-κB/Caspase-3 Pathways.

Despite being a potent anticancer drug, cisplatin has limited applicability due to its adverse effects, such as testicular damage. Consequently, reducing its toxicity becomes necessary. In this study, a selective phosphodiesterase-3 inhibitor, cilostazol, which is used to treat intermittent claudication, was examined for its ability to abrogate cisplatin-induced testicular toxicity. Its ameliorative effect was compared to that of two phosphodiesterase inhibitors, tadalafil and pentoxifylline. The study also focused on the possible mechanisms involved in the proposed protective effect. Cisplatin-treated rats showed a significant decrease in sperm number and motility, serum testosterone, and testicular glutathione levels, as well as a significant elevation in malondialdehyde, total nitrite levels, and the protein expression of tumor necrosis factor-alpha, nuclear factor-kappa β, and caspase-3. These outcomes were confirmed by marked testicular architecture deterioration. Contrary to this, cilostazol, in a dose-dependent manner, showed potential protection against testicular toxicity, reversed the disrupted testicular function, and improved histological alterations through rebalancing of oxidative stress, inflammation, and apoptosis. In addition, cilostazol exerted a more pronounced protective effect in comparison to tadalafil and pentoxifylline. In conclusion, cilostazol ameliorates cisplatin-induced testicular impairment through alteration of oxidative stress, inflammation, and apoptotic pathways, offering a promising treatment for cisplatin-induced testicular damage.

Novel Gastroprotective and Thermostable Cocrystal of Dimethyl Fumarate: Its Preparation, Characterization, and In Vitro and In Vivo Evaluation.

Crystallization has revolutionized the field of solid-state formulations by modulating the physiochemical and release profile of active pharmaceutical ingredients (APIs). Dimethyl fumarate (DF), an FDA-approved first-line drug for relapsing-remitting multiple sclerosis, has a sublimation problem, leading to loss of the drug during its processing. To tackle this problem, DF cocrystal has been prepared by using solvent evaporation technique using nicotinamide as a coformer, which has been chosen based on in silico predictions and their ability to participate in hydrogen bonding. Fourier transform infrared (FT-IR), powder X-ray diffraction (PXRD), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), and sublimation analysis have characterized the cocrystal and its thermostability. Comparative analysis of the release profile has been done by the dissolution and pharmacokinetic study of DF and its cocrystal. Formulated cocrystal is noncytotoxic, antioxidant and inhibits interleukin-6 and tissue necrosis factor-α in peripheral blood mononuclear cells induced by lipopolysaccharide. We have obtained a thermostable cocrystal of DF with a similar physicochemical and release profile to that of DF. The formulated cocrystal also provides a gastroprotective effect which helps counterbalance the adverse effects of DF by reducing lipid peroxidation and total nitrite levels.

Impact of water temperature on the shipping of berried female broodstock (Macrobrachium rosenbergii): A study on survival, egg retention, hatching duration, and hatching success rate

This study evaluated the impact of different water temperatures on shipping berried female Macrobrachium rosenbergii broodstocks. The broodstocks, averaging 23±0.07 g in weight and 12±0.1 cm in length, were shipped in styrofoam boxes containing 24L of purified freshwater. Three temperature conditions were tested: 28.5±0.5oC (control), 25.5±0.5oC (T1), and 21.5±0.5oC (T2). Various water quality parameters were measured. Mortality rates were significantly lower in T2 (2.60±0.41%) and T1 (8.96±2.09%) compared to the control (24.89±4.96%) (p&lt;0.05). The percentage of healthy berried females was higher in T2 (64.18±3.77%) and T1 (56.12±0.59%) than in the control (39.43±2.44%) (p&lt;0.05). T2 exhibited the lowest egg weight loss (6.17±0.66 g) and the shortest hatching period (26.33±3.30 hrs) with the highest hatching success rate (90.68±0.34%) (p&lt;0.05). Dissolved oxygen levels decreased more in the control group compared to T1 and T2 (p&lt;0.05). Total nitrite levels increased significantly in the control group compared to T1 and T2 (p&lt;0.05). The study concludes that cooler shipping temperatures, particularly around 21.5oC, benefit the survival, health, and hatching performance of berried female M. rosenbergii broodstocks.

Therapeutic Potential of Selenium Nanoparticles on Letrozole-Induced Polycystic Ovarian Syndrome in Female Wistar Rats.

Polycystic ovarian syndrome (PCOS) is considered the most frequent gynecological endocrine disorder that causes anovulatory infertility. The current study aimed to investigate the potential significance of selenium nanoparticles (SeNPs), an IL-1 inhibitor, in the treatment of letrozole-induced PCOS in rats that satisfied the metabolic and endocrine parameters found in PCOS patients. Letrozole (2ppm, per orally, p.o.) was given orally to female Wistar rats for 21days to develop PCOS. After PCOS induction, rats were given SeNPs (25ppm/day, p.o.), SeNPs (50ppm/day, p.o.), or metformin (2ppm/day, p.o.) for 14days. PCOS was associated with an increase in body weight, ovarian weight, ovarian size, and cysts, as well as an increase in blood testosterone, luteinizing hormone (LH), and insulin, glycaemia, and lipid profile levels. The SeNP administration decreased all of these variables. Furthermore, SeNPs significantly reduced letrozole-induced oxidative stress in the ovaries, muscles, and liver by decreasing elevated levels of malondialdehyde and total nitrite while raising suppressed levels of superoxide dismutase and catalase. SeNPs increased the amounts of the protective proteins Kelch-like ECH-associated protein 1 (Keap-1), nuclear factor erythroid 2-related factor 2 (Nrf2), and OH-1. It was depicted from the study that SeNPs reduce the upregulation of inflammatory cytokines that are interleukin 6 (IL-6), tumour necrosis factor α (TNF-α), and the interleukin 1 (IL-1). Our findings show that SeNPs, through their antioxidant and anti-inflammatory characteristics, alleviate letrozole-induced PCOS.

Effect of Stocking Density on Growth, Water Quality Changes and Cost Efficiency of Butter Catfish (Ompok bimaculatus) during Seed Rearing in a Biofloc System

Biofloc technology is a modern-day high-density fish culture system employing heterotrophic conversion of nitrogenous waste into useful flocs for water quality control and improved welfare. However, optimization of the stocking density for the target species during seed rearing is the key to a successful farming operation. The study evaluated the effect of different stocking density on the growth, feed utilization, digestive physiology and economics in a biofloc-based seed rearing of butter catfish, O. bimaculatus. Advanced fry (1.21 ± 0.08 g) was reared in a zero-water exchange biofloc system for 90 days at stocking densities of 0.5 g/L(T1), 1.0 g/L(T2), 1.5 g/L(T3) and 2.0 g/L(T4). The observed water quality indicates a reduction in DO and pH in T4, while the total ammonia nitrogen and nitrite levels remained low in T1. Among the groups, highest weight gain was noticed in the lowest stocking density (0.5 g/L) (p &lt; 0.05), which coincides with a better feed conversion ratio. Similarly, the digestive enzyme (protease, amylase, and lipase) secretion was higher in T1. Profitability assessment describes the possibility of low profit in T4, in the case where the fish’s sale price is based on harvested size. T1 showed higher individual growth and higher profit. Overall, a low stocking density of 0.5 g/Lis optimum for augmenting growth, feed utilization, physiological function and economic performance of O. bimaculatus. The study provides direction for a low-stocking oriented ecological and economically sustainable method of seed production of butter catfish in a biofloc system.

Environmental quality and ecotoxicity of sediments from the lower Salado River basin (Santa Fe, Argentina) on amphibian larvae

The lower Salado River basin receive agricultural, industrial and domestic waste water. So, the aim was to evaluate the quality of three sampling sites that belong to the Salado River basin (S1: Cululú stream; S2: Salado River, at Esperanza City, S3: Salado River at Santo Tomé City) based on physicochemical parameters, metals and pesticides analyses and ecotoxicity on Rhinella arenarum larvae. R. arenarum larvae (Gosner Stage -GS- 25) were chronically exposed (504h) to complex matrixes of surface water and sediment samples of each site for the determination of the survival rate. Biomarkers of oxidative stress, neurotoxicity and genotoxicity were analyzed in R. arenarum larvae (GS. 25) after exposure (96h) to the complex matrix of water and sediment. The water quality index showed a marginal quality for all sites, influenced mainly by low dissolved oxygen, high total suspended solid, phosphate, nitrite, conductivity, Pb, Cr and Cu levels. Metal concentrations were higher in sediment than in water samples (˜34-35000 times). In total, thirty different pesticides were detected in all water and sediment samples, S1 presented the greatest variety (26). Glyphosate and AMPA were detected in sediments from all sites, being higher in S3. N,N-Diethyl-meta-toluamide (DEET) and atrazine were detected in all water samples. Greatest mortality was observed in larvae exposed to samples from S1 from 288h (43.3%), reaching a maximum value of 50% at 408h. Oxidative stress and genotoxicity were observed in larvae exposed to S1 and S3 matrix samples. Neurotoxicity was observed in larvae exposed to all matrix samples. The integrated biomarker response index showed that larvae exposed to S1 and S3 were the most affected. According to the physicochemical data and the ecotoxicity assessment, this important river basin is significantly degraded and may represent a risk to aquatic biota, especially for R. arenarum larvae.

Management of inorganic nitrogen compounds in a closed aquaculture system during imitation for nursery of Litopenaeus vannamei under brackish condition

It was aimed to estimate the efficiency of management of inorganic nitrogen compounds under a closed system condition, via addition of carbon source. For this purpose, an imitation experiment for nursery of Litopeanaeus vannamei postlarvae under a brackish condition was conducted, in two closed systems with a salinity of about 18‰: systems with (CS) and without (control) addition of carbon source (molasses) at a carbon to nitrogen ratio (C:N) of 20:1. The levels of total ammonia nitrogen (TAN, 1.39±0.14 mg L−1), nitrite (0.023±0.003 mg L−1) and nitrate (0.49±0.06 mg L−1) in CS system were significantly lower than those in the control system (6.92±0.60, 0.809±0.050 and 2.39±0.47 mg L−1, P < 0.05). The results indicated that carbon source addition to the closed system imitating nursery of L. vannamei postlarvae under a brackish condition well managed the level of inorganic nitrogen compounds during experiment, making it possible to environment-friendly culture L. vannamei at inland areas under a closed condition.

The effects of different stocking densities on nursery performance of Banana shrimp (Fenneropenaeus merguiensis) reared under biofloc condition

Abstract The effects of banana shrimp Fenneropenaeus merguiensis stocking density on water quality, growth performance, survival rate and body composition was assessed in a biofloc system with limited water exchange. The study was conducted for 32 days with an average larvae weight of 10 ± 0.85 mg in fiberglass tanks containing 120 L of water at four stocking densities. Five experimental treatments consisted of a control (density 1000 shrimps/ m3) with 50% daily water exchange and four biofloc treatments with limited water exchange (0.5% daily) at four stocking levels (1000 shrimps, T1; 2000 shrimps, T2, 3000 shrimps, T3 and 4000 shrimps, T4/ m3) were considered. According to the results, total ammonia nitrogen (0.99 mg/L) and nitrite levels showed higher amounts in the control compared with the other treatments (P&lt;0.05). Growth performance and survival rate (95.55%) in the biofloc treatment with a density of 1000 shrimps/ m3 were higher than the other treatments (P&lt;0.05). The proximate composition of shrimp body and biofloc produced in rearing tanks depended on the stocking density, so the shrimp body ash increased along with the enhancement of stocking density. The lowest amount of ash (31.53± 0.81%) and protein (26.38 ± 1.26) of bioflocs was observed in T1 treatment. The present study showed that stocking density affects the water quality, growth performance, survival rate and body composition of banana shrimp larvae in a biofloc system. More improved indices of water quality, growth performance and survival rate were observed with the least stocking density of 1000 shrimps/m3 in the limited water exchange system.

Efficacy of quick-start nitrifying products in controlled fresh-water aquaria

Quick-start nitrifying products (QSNP) are sold to aquarium hobbyists with the claim that the nitrogen cycle is rapidly initiated allowing for instant addition of fish. Despite these claims, none of these products have been the subject of peer-reviewed evaluation. Six 10-gallon aquaria were used to simulate a naïve fresh water system. Water temperature, pH and dissolved oxygen were measured to ensure stability between aquaria. On Day 0, 1.0-ppm ammonium hydroxide was added to each of the aquaria. Five aquaria received a different QSNP on Day 1 of the study. One aquarium acted as a control, receiving no QSNP. Total ammonia nitrogen (TAN), nitrite and nitrate levels were monitored every 48-hours for 14 days. Total ammonia nitrogen concentrations were significantly lower in the Tetra® samples compared to all other samples and controls (all p<0.001). Additionally, TAN concentrations were significantly lower on days 4-14 compared to baseline (all p<0.001). There were no significant differences in nitrite concentrations by treatment (F=1.3, p=0.263) or time (F=1.0, p=0.416). Nitrate concentrations were significantly higher in the Cycle® (p<0.001) and Tetra® (p=0.001) samples compared to the control samples. Nitrate concentrations were also found to be significantly higher on days 4 (p=0.027), 10 (p=0.041), 12 (p=0.011), and 14 (p=0.007) compared to baseline. Four out of five QSNP failed to reduce TAN concentrations from baseline levels over the 14-day test period. One of the QSNP appears to significantly be able to reduce TAN concentrations in controlled freshwater aquaria. Quick-start nitrifying products should not be recommended as a sole method when initiating the nitrogen cycle in fresh water aquaria until further studies have evaluated these products.

Polyculture of sea grape (Caulerpa lentillifera) with different stocking densities of whiteleg shrimp (Litopenaeus vannamei): Effects on water quality, shrimp performance and sea grape proximate composition

The polyculture of sea grape with whiteleg shrimp is considered as one of the strategic approaches to sustainable shrimp production. This is the first study to investigate the effects of integrating sea grape (Caulerpa lentillifera) with different densities of whiteleg shrimp (Litopenaeus vannamei) on water quality, shrimp performances and sea grape proximate composition. The experiment was executed in indoor tank systems, comprising five treatments in randomly designed triplicate tanks, with five levels of shrimp densities (100, 200, 300, 400, and 500 individuals m−3) integrated with sea grape (1 kg m−3) for 56 days. The results showed that the polyculture of sea grape with shrimp significantly enhanced sea grape biomass and proximate composition in terms of protein, lipid and ash contents while maintaining adequate levels of total ammonia nitrogen (TAN), nitrite (NO2−), nitrate (NO3−), and phosphate (PO43−) in the rearing tanks at high shrimp densities. Shrimp growth rates (weight gain, daily weight gain, and specific growth rate) tended to decrease at higher density levels, but there were no statistical differences (p > 0.05) among treatments at stocking densities ranging from 200 to 400 individuals m−3. Although shrimp survival was significantly reduced as stocking densities increased from 400 individuals m−3 upward; the lowest and highest shrimp yields were obtained at densities of 100 and 400 individuals m−3, respectively. Feed conversion ratios were higher at higher shrimp density; however, no significant difference was not observed between 300 and 400 individual m−3 groups. These findings indicated that polyculture of sea grape with whiteleg shrimp can perform up to 400 individuals m−3 while maintaining suitable water quality parameters and sustaining improved production efficiency in the culture unit.