Search

Pseudomonas aeruginosa (P. aeruginosa) is an opportunistic bacterium that is widely distributed in aquatic environments and causes major economic losses in fish and public health hazards.This study aimed to identify the occurrence of P. aeruginosa in samples collected from fish and fish handlers, and to investigate the antimicrobial susceptibility, virulence determinants, and biofilm genes of P. aeruginosa isolates. A total of 276 samples were cross-sectionally collected from Nile tilapia (53), Golden grey mullet (52), Mediterranean horse mackerel (50), Striped red mullet (71), and fish handlers (50) at five different retail fish markets in Damietta Governorate, Egypt. Pseudomonas species (spp.) were biochemically identified in 57.9% of the total examined samples. Peudomonas aeruginosa were the most prevalent species isolated from the fish and human samples via PCR technique. Peudomonas aeruginosa isolates exhibited full resistance (100%) to tobramycin (TOB), gentamicin (CN), and colistin (CL), with a high level of susceptibility (88.5%) to imipenem (IPM) using the disk diffusion method. Most P. aeruginosa isolates (84.6%) exhibited drug resistance, with 61.5% were multidrug resistance (MDR) and 23.1% were extensive drug resistance (XDR). Most isolates had at least four virulence-associated genes (lasB, toxA, exoU, and oprL) and three biofilm genes (psIA, peIA, and lasR) by using uniplex PCR. The lasI, and rhlR Quorum Sensing (QS) genes were identified in 84.6% and 61.5% in the examined P. aeruginosa isolates, respectively. The highest mortality rate in Nile tilapia experimentally infected with P. aeruginosa isolate encoding most of virulent genes. Multivariate analyses revealed high heterogeneity among the examined isolates. This study revealed the emergence of virulent and drug resistant P. aeruginosa isolates in fish, poses high risks to consumers and food. Thus, strict hygienic measures should be considered when catching, handling, and storing fish, in addition to the routine application of antimicrobial susceptibility testing. [ABSTRACT FROM AUTHOR]

The present study investigated the effect of the proviron, oral anabolic steroid on undifferentiated Nile tilapia (Oreochromis niloticus) larvae sex reversal and to compare its effect with that of 17 α-methyltestosterone. Thus, doses of 25 mg, 50 mg and 75 mg proviron versus 60 mg/kg for 17 α-methyltestosterone were incorporated in the diet of 10-days-post-fertilization old larvae for 28 days. At the end of the treatment and after pre-growth until 90 days post-fertilization, we carried out sexing. Results displayed male rates ranged from 65.7 ± 3.1% to 96.7 ± 1.1% for treatments with 25 mg and 75 mg proviron, respectively and was 99 ± 0.1% for that with 17 α-methyltestosterone. However, no significant difference (p > .05) was found between the average male rate of larvae fed the feed containing 75 mg of proviron and that of larvae fed the feed that containing 17 α-methyltestosterone. [ABSTRACT FROM AUTHOR]

The use of nutraceuticals in aquaculture is getting attention to minimize oxidative stress and increase immunity of aquatic animals. In our experiment, we tested the potency of Phyllanthus niruri, as a stress-reducing and immune-stimulating agent in Nile tilapia, Oreochromis niloticus. We reared fish in a recirculating system for 90 days at low (5 g/L) and high (30 g/L) densities. We fed half of the low and high-density fish with commercial feed (control feed) and the other half, with 5% Phyllanthus niruri incorporated into commercial feed (supplemented feed). We assessed plasma cortisol, blood glucose, packed cell volume, plasma proteins, phagocytic capacity, respiratory burst activity, and lysozyme activity. None of these parameters showed any significant difference among the experimental groups. Based on our findings, we conclude that Phyllanthus niruri does not have any potential role in modulating stress and immune response in fish as a nutraceutical. [ABSTRACT FROM AUTHOR]

ABSTRACT Recent years have witnessed a remarkable global surge in fish production, with Nile tilapia (Oreochromis niloticus) emerging as a prominent contributor owing to its high demand as a nutritious food source. However, unlike terrestrial species, maintaining genealogical control and collecting phenotypic data in fish farming poses significant challenges, necessitating advancements to support genetic improvement programmes. While conventional methods, such as body measurements using rulers and photographs are prevalent in data collection, the potential of ultrasound—a less invasive and efficient tool for fish measurement—remains underexplored. This study assesses the viability of ultrasonography for genetically selecting carcass characteristics in Nile tilapia. The investigation encompasses data from 897 animals representing 53 full‐sib tilapia families maintained in the genetic improvement programme at the Federal University of Lavras. To measure carcass traits, the animals were sedated with benzocaine and ultrasound images were obtained at three distinct points. Subsequently, the animals were euthanised through medullary sectioning for further carcass processing. After evisceration, filleting and skinning, all weights were meticulously recorded. (Co)variance components and genetic parameters of the measured traits were estimated using the Bayesian approach by Gibbs sampling implemented in MTGSAM (Multiple Trait Gibbs Sampling in Animal Models) software. Heritabilities estimated for the studied carcass traits were moderate, ranging from 0.23 to 0.33. Notably, phenotypes derived from ultrasound images demonstrated substantial genetic correlations with fillet yield (0.83–0.92). In conclusion, this study confirms that indirect selection based on ultrasound images is effective and holds promise for integration into tilapia breeding programmes aimed at enhancing carcass yield. [ABSTRACT FROM AUTHOR]

This research evaluated the efficacy of mixed Bacillus strains probiotic supplements in mitigating acute thermal-induced stress in Nile tilapia (Oreochromis niloticus). Three experimental fish groups involved 135 Nile tilapia (49 ± 2 g); one control (no added probiotics), 0.5, and 1% of selected Bacillus strains (B. subtilis, B. licheniformis, and B. pumilus) for 58 days. After the feeding period, growth parameters, immunological parameters, stress biochemical markers, and antioxidant parameters in addition to genes related to stress and histopathological changes in fish, were assessed; subsequently subjected to heat shock at 36 ± 0.5 ◦C for 2 h. Before the heat challenge, our results exhibited a marked increase in the growth efficacy (P < 0.05), lower marked serum levels of triglycerides and cholesterol, and tissue malondialdehyde (MDA) levels along with significantly increased superoxide dismutase (SOD) and catalase (CAT) enzymes activity in fish-fed Bacillus probiotic at 0.5% concerning the control group (P < 0.05). There were no significant changes in the serum levels of glucose, cortisol, lactate, phagocytic activity, respiratory burst (ROS), total immunoglobulin Ig, alanine aminotransferase (ALT), aspartate aminotransferase (AST), lactate dehydrogenase (LDH), total protein, albumin, globulin, uric acid, urea, creatinine, as well as HSP70, GST, and GPx mRNA expression in most of the probiotic groups compared to the control group (P > 0.05). When Nile tilapia was exposed to heat stress, supplementation with Bacillus probiotic in the diet significantly decreased most of the indices related to serum biochemical (ALT (P < 0.01; P < 0.001), AST (P < 0.01), LDH (P < 0.01), urea (P < 0.05), and creatinine (P < 0.01)), triglycerides (P < 0.001; (P < 0.01)), cholesterol (P < 0.01; (P < 0.05)), glucose (P < 0.001), and cortisol (P < 0.01; (P < 0.05)), with tissue oxidative stress MDA levels (P < 0.05), and HSP70 mRNA expression (P < 0.01; P < 0.001), aligned with the stressed control group. In addition, a notable upsurge in the total protein, albumin, globulin, phagocytic and ROS activities, and total Ig, as well as the enzymatic antioxidant ability (SOD, CAT) (P < 0.01), with GST and GPx mRNA expression (P < 0.05; P < 0.01), were shown in fish-fed Bacillus spp. post-exposure compared with the stressed control group. Besides, no histopathological alterations were revealed in the spleen and brain of fish pre- and post-heat exposure. According to our findings, diet supplementation of Bacillus species has the potential to combat the suppressive effects of heat shock in Nile tilapia. Highlights: • Heat exposure altered the phagocytic activity, ROS, and total Ig and hepatic and liver biomarkers. • Heat exposure induced oxidative damage and pathological alterations of different tissues. • Heat exposure enhanced the expression of HSP70 in the head kidney of tilapia. • Mixed Bacillus spp., a dietary probiotic, effectively mitigated these heat-induced toxicity. [ABSTRACT FROM AUTHOR]

Rationing aquaculture farming feed is challenging for producers due to high feed costs, representing 30%–60% of the total operating costs. Therefore, optimal timing of feeding could lead to improved economic returns from an aquatic system. An optimal dynamic feeding model has been determined considering the von Bertalanffy growth model. A bioeconomic model of tilapia production in Mexico for specific markets was used for numerical illustration. The von Bertalanffy growth model was parameterized with experimental data from tilapia (Oreochromis niloticus) fed four ration sizes (50%, 80%, 100%, and satiety), in order to determine different optimal rationing for different fish sizes (200, 300, and 400 g), market prices (Monterrey, Cancún, Mexico City, and On site), and optimal harvesting times (OHT), considering the time value of money. The results of the modeled optimal feeding trajectories show a continuous decrease from stocking to reach a minimum value and then slightly approaching the harvest size. This result contrasts with the recommendations of the feed suppliers and with those found when a potential growth model was used. The results in the case study showed that the Monterrey market presented the highest present value of the benefits in the OHT and the different market sizes. The implications of the Bertalanffy model for optimal rationing trajectories are presented in the discussion. [ABSTRACT FROM AUTHOR]

Background: Streptococcus agalactiae (Group B streptococcus, GBS) induces a serious infection that can harm not only aquatic life but also humans and other animals. In a fish farm in southern Egypt, Nile tilapia (Oreochromis niloticus) has developed an epidemic with clinical symptoms resembling piscine streptococcosis. Results: Initial microscopic inspection of the affected fish brain and kidney indicated the presence of Gram-positive cocci. S. agalactiae was effectively isolated and identified using nucleotide homology of the 16S rRNA and species-specific PCR. The partial 16S rRNA sequence was deposited in the GenBank database at the NCBI and given the accession number MW599202. Genotyping using RAPD analysis indicated that the isolates in the present study belonged to the same genotypes and had the same origin. The challenge test, via immersion (9.2 × 107, 9.2 × 106, and 9.2 × 105 CFU/ml for 1 h) or intraperitoneal injection (4.6 × 107, 4.6 × 106, and 4.6 × 105 CFU/fish), elicited clinical symptoms resembling those of naturally infected fish with a mortality rate as high as 80%. The ability to create a biofilm as one of the pathogen virulence factors was verified. Zinc oxide nanoparticles and the ethanolic leaf extracts of nine medicinal plants demonstrated considerable antibacterial activities against the tested S. agalactiae strain with low minimum bactericidal concentrations (MBC) and minimum inhibitory concentrations (MIC). The ethanolic leaf extracts from Lantana camara and Aberia caffra showed potent antibacterial activity with MBC values of 0.24 and 0.485 mg/ml, and MIC values of 0.12 & 0.24 mg/ml, respectively. Conclusion: This study isolated S. agalactiae from O. niloticus mortalities in a fish farm in Assiut, Egypt. The pathogen persists in fish environments and can escape through biofilm formation, suggesting it cannot be easily eliminated. However, promising findings were obtained with in vitro control employing zinc oxide nanoparticles and medicinal plant extracts. Nevertheless further in vivo research is needed. [ABSTRACT FROM AUTHOR]

Background: Saline-alkaline water aquaculture has become a key way to mitigate the reduction of freshwater aquaculture space and meet the increasing global demand for aquatic products. To enhance the comprehensive utilization capability of saline-alkaline water, it is necessary to understand the regulatory mechanisms of aquatic animals coping with saline-alkaline water. In this study, our objective was to elucidate the function of proline metabolism in the alkaline adaptation of Nile tilapia (Oreochromis niloticus). Results: Expose Nile tilapia to alkaline water of different alkalinity for 2 weeks to observe changes in its growth performance and proline metabolism. Meanwhile, to further clarify the role of proline metabolism, RNA interference experiments were conducted to disrupt the normal operation of proline metabolic axis by knocking down pycr (pyrroline-5-carboxylate reductases), the final rate-limiting enzyme in proline synthesis. The results showed that both the synthesis and degradation of proline were enhanced under carbonate alkalinity stress, and the environmental alkalinity impaired the growth performance of tilapia, and the higher the alkalinity, the greater the impairment. Moreover, environmental alkalinity caused oxidative stress in tilapia, enhanced ion transport, ammonia metabolism, and altered the intensity and form of energy metabolism in tilapia. When the expression level of the pycr gene decreased, the proline metabolism could not operate normally, and the ion transport, antioxidant defense system, and energy metabolism were severely damaged, ultimately leading to liver damage and a decreased survival rate of tilapia under alkalinity stress. Conclusions: The results indicated that proline metabolism plays an important role in the alkaline adaptation of Nile tilapia and is a key regulatory process in various biochemical and physiological processes. [ABSTRACT FROM AUTHOR]

Lowering nanoparticles (NPs) toxicity before discharge into aquatic environments and employing agricultural waste materials for environmental sustainability are necessary nowadays. Since this has never been done, this work examines how green CuO NPs treated with rice husk (RH) as a bio-adsorbent may be safer for Nile tilapia (Oreochromis niloticus) than chemically manufactured ones. So, five groups of fish were randomly placed in glass aquaria. One group was a control, and four groups received 50 mg/L green and chemically produced CuO NPs (GS and CS) with and without RH for 24, 48, and 96 h. RH was collected from all groups, and the results showed GS-CuO NPs had a greater adsorptive capacity than CS-CuO NPs after all time intervals. After analyzing fish indicators in all groups compared to the control, higher Cu bioaccumulation was exhibited in the liver and gills. The liver and gills showed elevated levels of glutathione peroxidase (GPx), catalase (CAT), and thiobarbituric acid reactive substances (TBARS), while the levels of glutathione reduced (GSH) were significantly lower. In addition, Cu exposure impaired liver and gill histology. Finally, our results indicated that using RH as an adsorbent for CuO NPs after their green synthesis instead of chemical synthesis before they enter the aquatic environment can enhance the overall health of fish and environmental sustainability. [ABSTRACT FROM AUTHOR]

Background: Hypoxia stress resulted in mortality during the fish aquaculture program, affecting the sustainable development of the aquaculture industry. The Egyptian strain of O. niloticus showed a strong ability to hypoxia. In this study, a Nile tilapia strain that was kept and selected for 45 years by the author's team was used to elucidate the mechanism of the hypoxia response in the liver, including the identification of metabolic pathways and genes, involved in the hypoxia response of this strain. Results: The effects of hypoxia stress were detected at 0-hour, 6-hour, and 72-hour time points (0 h, 6 h, 72 h) on tilapia liver at 1 mg/L dissolved oxygen conditions. The blood triglyceride, blood glucose and cholesterol values exhibited significantly different change trends, but the hemoglobin content showed no significant differences between 0 h, 6 h and 72 h (P > 0.05). The activities of catalase (CAT), glutathione peroxidase (GSH-PX), total antioxidant capacity (T-AOC), lactate dehydrogenase (LDH), and acid phosphatase (ACP) in the liver tissue gradually increased at 0 h, 6 h and 72 h (P < 0.05). Histological analyses revealed structural changes in intracellular lipid droplets, nuclear migration and dissolution, and cell vacuolization in liver tissues. Six pathways were identified as the main enriched metabolic pathways according to the transcriptome profiling analysis, which were protein processing in endoplasmic reticulum, steroid biosynthesis, peroxisome, PPAR signaling pathway, glycolysis/gluconeogenesis and Insulin signaling pathway. The expressions of the important differentially expressed genes were verified by qPCR analysis, including erola, LOC100692144, sqle, cratb, pipox, cpt1a2b, hik and acss2l, ehhadh, prkcz, fasn and plaa, which showed the same expressions trends as those of RNA-Seq. Conclusions: The Nile tilapia strain improves the abilities of hypoxia response through energy metabolism. Antioxidant enzyme measurements in the liver indicate that these five antioxidant enzymes play important roles in protecting the body from hypoxic damage. The histological changes in liver cells indicate that the damage caused by hypoxia stress. The immune-related metabolic pathways and energy metabolism-related pathways were obtained by transcriptome profiling, and these metabolic pathways and the differentially expressed genes selected from these metabolic pathways may be involved in the mechanism of hypoxia tolerance in this strain. These findings provide a better understanding of the hypoxia response mechanism of fish, and represent a useful resource for the genetic breeding of O. niloticus. [ABSTRACT FROM AUTHOR]

Fish feed is critical in aquaculture production, accounting for over 60% of operational costs, with protein being the most expensive component. Traditionally, fish meal (FM) has been the primary protein source. However, due to declining capture fisheries and high demand, FM has become scarce and costly, necessitating the search for alternative, low‐cost, and nutritionally balanced protein sources. A 180‐day feeding experiment was conducted to evaluate the effects of replacing FM with a combination of cottonseed and sunflower meal (SFM) in Nile tilapia diets on growth performance, protein digestibility, and economic returns. Freshwater shrimp meal was replaced at 25%, 50%, 75%, and 100% (diets D1, D2, D3, and D4) and compared to the control diet (D0) containing only FM. Monosex Nile tilapia fingerlings (25 ± 0.01 g) were allocated to 15 cages within an 800 m2 earthen pond. Fish on diets D0 and D1 showed superior growth performance metrics, including final mean body weight, weight gain, daily weight gain, specific growth rate, feed conversion ratio, and survival rate (p > 0.05), compared to diets D2, D3, and D4. Growth performance declined significantly with increasing levels of the plant protein mixture (p < 0.05). Diet D0 had the highest apparent protein digestibility, while D4 had the lowest. Cost‐benefit analysis revealed that diet D0 had the highest production cost, followed by diets D1, D2, D3, and D4, with no significant cost difference between D0 and D1 (p > 0.05). Thus, the plant protein mixture can effectively replace FM at a 25% inclusion level in Nile tilapia diets. [ABSTRACT FROM AUTHOR]

This study aimed to conduct a multidisciplinary investigation integrating detailed morphology, molecular characterization, water parameters, histopathology alteration, and the trials of treatment of Clinostomum spp. In this study, 300 Nile tilapia (Oreochromis niloticus) were collected from the farmed and wild Nile River at Al Bahr Al Aazam, Giza Governorate to assess Clinostomid infection prevalence. Fish and water samples were collected from private fish farms, and water drains at Dakahlia, and Giza, Egypt. Analysis of the water revealed inadequate water quality, particularly in the fish farms. Snails and piscivorous birds were abundant at fish collection sites. The recovered Clinostomid MCs morphological characteristics and COI gene sequence analysis identified them as Clinostomum complanatum, C. phalacrocoracis, and Euclinostomum heterostomum. Clinostomid MCs disturbed the fish's hematological and biochemical blood parameters. Bath treatment of parasitized fish with praziquantel (2 mg/L for 24 h) revealed a significant reduction in the number of vital MCs vs. infected fish (non-treated). Praziquantel (PZQ) is an effective and safe therapy for controlling Clinostomid infections affecting farmed Nile tilapia. The current findings indicate a link between poor environmental conditions and Clinostomum infections in tilapia. The study highlights the impacts of Clinostomid MCs on fish health and recommends bath treatment with PZQ as an efficient control method for these dangerous parasites to protect human and fish health. [ABSTRACT FROM AUTHOR]

In this study, we described immediate/acute reactions to stress-related chemical cues (SC – Stress Cue) in fish. Specifically, we evaluated the effects of SC on ventilation rate (VR) and feeding behavior in Nile tilapia (Oreochromis niloticus), a highly relevant species for world aquaculture, therefore, to understand the diversity of stressful contexts and stress responses in this species have important practical applications (stress reduction). Stress cue was obtained from conspecifics exposed to a handling stressor. Stress was confirmed by measuring plasma cortisol levels. The responses to SC were contrasted to chemical control cues: a cue originated from non-stressed conspecifics and pure water (vehicle control). We observed that Nile tilapia exposed to SC had an increase in VR, but without effects on feeding behavior (feeding latency and ingestion). Thus, the SC is a stressor that induces readily stress response (VR increase), suggesting sympathetic activation, but did not change feeding performance. In practical terms, it is positive because although social propagation of stress via SC elicits a stress response, it did not harm appetite. [ABSTRACT FROM AUTHOR]

Aeromonas veronii, a threatening fish pathogen, is implicated in food-borne infections in humans, contributing to substantial economic losses in the aquaculture sector. To examine the occurrence, resistance profiles, 16SrRNA sequence analysis, virulence-determinant and resistance genes, and pathogenicity of A. veronii isolated from Nile tilapia (Oreochromis niloticus), almost 150 fish weighing 75 ± 10 g (apparently healthy; n = 50 and moribund fish; n = 100) were collected from commercial farms in Ismailia Governorate, Egypt. Subsequently, the clinical, post-mortem, and bacteriological examinations were carried out. The overall prevalence of A. veronii in the collected O. niloticus was 18.6% (28/150), where the pathogen was only detected in the moribund one. Phylogenetic analysis revealed that the tested isolate exhibited significant genetic identity with other strains from diverse locations and origins in China and Egypt. PCR showed that aerA (95.4%) was the most predominant virulence gene associated with A. veronii isolates retrieved from O. niloticus, followed by hly (80.3%), ast and ser (69.7% for each), and alt (50.1%). Moreover, 40.9% of the obtained isolates were extensively drug-resistant (XDR) to seven classes and inherited blaTEM, tetA, blaCTX-M, and sul1 genes. Besides, 6.1% of the recovered isolates were carbapenem-resistant and XDR to seven classes harboring blaTEM, blaNDM, blaCTX-M, sul1, and tetA genes. The cumulative mortality rate was 86.7% in the fish group injected with a virulent A. veronii strain at a concentration of 3 × 108 CFU/mL. Concisely, this study underscored the existence of XDR A. veronii in O. niloticus specifying a public health hazard. XDR A. veronii isolated from O. niloticus commonly inherited aerA, ast, ser, and alt virulence-determinant genes and blaTEM, sul1, blaCTX-M, and tetA resistance genes. [ABSTRACT FROM AUTHOR]

The purpose of the current study was to assess the effect of dietary supplements of either aqueous (AE) or ethanolic (EE) (Juniperus communis) leaf extracts on growth performance, intestinal health, hemato-biochemical indices, antioxidant, inflammation cytokine responses, and resistances against infection in Nile tilapia, Oreochromis niloticus. Fish groups were controlled with no extract (J1) and fed diets (J2, J3, J4, and J5) containing 1.0 and 2.0 g/kg aqueous and ethanolic extract for 60 days. Fish were given an intraperitoneal injection (IP) of Aeromonas hydrophila for 10 days after the feeding trial; then, the fish mortality was recorded. Growth, feed efficiency, and activity of endogenous enzymes (lipase, trypsin, chymotrypsin, and amylase) were significantly improved in all dietary J. communis groups, especially in J5, compared to other groups. Also, J5 showed the highest absorption area, muscularis, goblet cells, villi width, and fewer gut bacterial counts than the other groups. In addition, the J4 and J5 groups of tilapia fish exhibited a significant increase in the levels of total protein, serum albumin, globulin, hemoglobin, white blood cells, and hematocrit (P < 0.05), as well as a significant decrease in the levels of serum alanine, aspartate aminotransferases, glucose, and cholesterol compared to the J1 groups. Moreover, the J4 and J5 fish showed a significant decline in the levels of MDA with improvements in antioxidant (SOD, CAT, and GPX) and immunological (lysozyme, immunoglobulin M, and complement C3) indices compared to the J1 group. Fish in J4 and J5 exhibited downregulated levels of il-8, il-10, il-1β, tnf-α, ifn-γ, and hsp70 genes compared to other groups. In contrast, hepatic catalase (cat), superoxide dismutase (sod), and interleukin (il-10) gene expressions were upregulated. The lowest fish mortality after the bacterial challenge was recorded in the J5 group. These findings suggest that 2.0 g/kg feed ethanolic extract of J. communis-fed Tilapia fish fingerlings improved their growth and intestinal health, boosted their immune systems and antioxidant responses, and increased their resistance to A. hydrophila. [ABSTRACT FROM AUTHOR]

This study evaluates the anesthetic effectiveness and potential reduction of toxicity in Nile tilapia (Oreochromis niloticus) through the use of clove, cinnamon, and tea tree essential oils. We evaluated genetic damage, enzymatic activity, and gene expression. We conducted two experiments. In experiment 1, we individually evaluated the anesthetic efficiency and genotoxicity of these essential oils. In experiment 2, we assessed their combined effects at different concentrations. Clove oil, particularly at the highest concentration (200 µL/L), induced genotoxic effects and oxidative stress in fish, leading to alterations in gene expression regulation and enzymatic activity. Tea tree and cinnamon oils, at concentrations of 75 and 100 µL/L, required longer times to induce fish to the anesthesia stage and were less efficient in achieving deep anesthesia stage. Notably, combining tea tree and cinnamon essential oils to clove oil showed promise as an alternative to using clove oil alone. This combination demonstrated potential as an effective anesthetic and may help mitigate the genotoxic effects associated with clove essential oil. Our findings suggest a viable option to minimize potential physiological damage during the anesthesia process in aquaculture, thereby promoting a balance between this necessary procedure and animal welfare. [ABSTRACT FROM AUTHOR]

Immunosaccharides such as β-glucans and fructooligosaccharide (FOS) strengthen the host's immune responses. This study examined the influences of three levels of the β-1, 3 glucan-FOS combination on Red tilapia performance. Four diets were prepared: T0 as a control, while T0.5, T1, and T1.5 indicate the addition of β-1, 3 glucan-FOS mixture at 0.5%, 1%, and 1.5%, respectively. Then, 240 red Tilapia (Oreochromis niloticus x O. mossambicus) (weight 6.1 ± 0.07gm) were allocated into four groups, and every group was fed tested diets for 56 days. After the feeding trial, growth parameters, erythrogram profile, liver and kidney function testes, glucose, histopathological analysis, and gene expressions for antioxidants, catalase (CAT) and glutathione peroxidase (GPX) besides growth hormone (GH) and insulin-like growth factor 1 IGF1-related markers were assessed. Red tilapia fed T0.5, T1, and T1.5 exhibited consistent growth, survival rate, and homeostasis compared with the control group. Different supplement concentrations displayed varying levels of responses. The hepatorenal biomarkers (alanine transaminase (ALT = SGPT) and aspartate transaminase (AST = SGOT), alkaline phosphatase (ALP = ALK), urea, and creatinine) and glucose showed a significant reduction in the supplemented groups compared with the control, especially in the T1 and T1.5 groups. The intestinal morphometric study revealed that fish group fed on T1 represented the best result, whereas group T1.5, followed by group T0.5, was moderately treated, compared to the control. The real-time quantitative reverse transcription PCR (qRT-PCR) analysis displayed up-regulated expression of antioxidant and growth-correlated genes in the T1.5 groups. After 56 days, the β-1,3 glucan-FOS fed groups also exhibited an increase in survival rates compared to the control when challenged with a pathogenic Vibrio alginolyticus. Current findings suggest that inclusion of β-1,3 glucan-FOS in diets could enhance red tilapia biochemical parameters, growth, and protection against pathogenic V. alginolyticus infection. [ABSTRACT FROM AUTHOR]

Recently, medical plants have been widely used as replacements for antibiotics in disease treatment. Because of its multiple medicinal uses, peppermint (Mentha piperita, MP) is a common herbal remedy. In the present study, MP powder was used as a feed additive to assess growth performance; hematological; biochemical and immune parameters; intestinal histology; and interleukin 1β (IL-1β) gene expression, as well as protection against Vibrio alginolyticus infection in Oreochromis niloticus. O. niloticus (n = 120, 25.66 ± 0.16 g) were fed diets containing 0 (CTR), 2, 3, or 4% MP for 60 days. The results revealed that the inclusion of 2% MP significantly improved the growth indices, intestinal morphological parameters, and reduced the feed conversion ratio. The 2% MP treatment significantly (P < 0.05) increased hematological parameters (red blood cell (RBC) count, white blood cell (WBC) count, packed cell volume% (PCV%), hemoglobin) compared with those of the CTR (P < 0.05). Additionally, feeding fish 2% MP diets decreased the levels of cholesterol and LDL (low-density lipoprotein). There were significant increases in immune responses (serum protein and phagocytic activity and index) and non-significant increases in the expression of IL-1β in the 2% MP group comparing with the other groups and the CTR group (P < 0.05). At the end of the feeding trial (60 days), fish were challenged with a virulent strain of Vibrio alginolyticus and the results showed that the mortality rate decreased in the 2% MP treatment group, followed by the 3% and 4% MP groups. Overall, the results revealed that the dietary inclusion of 2% MP can exhibit growth-promoting and immunostimulant effects for sustainable aquaculture. [ABSTRACT FROM AUTHOR]

In this study, we investigated the effects of the dietary addition of lavender essential oil (LEO) on mitigating the adverse effects of high stocking densities (HSD) in the Nile tilapia, Oreochromis niloticus. We used 216 fingerlings and randomly distributed them according to a 2 × 3 factorial design, comprising two stocking densities: a low stocking density (LSD, 2.92 kg/m3) and a high stocking density (5.85 kg/m3) and three levels of LEO, 0, 0.5%, and 1%, for 70 days. We evaluated their growth, digestive enzyme activity, blood biochemical parameters, immune/antioxidant indices, and intestinal morphology. All fish were intraperitoneally inoculated with Aeromonas veronii for a bacterial challenge test at the end of the feeding trial and monitored for 14 days. After 14 days, head kidney samples were collected from all fish to assess the level of expression of immune-related and apoptosis-related genes. Additionally, tissue samples were collected from the liver, kidney, and intestine to investigate the immunohistochemistry and histopathological alterations. The results showed that the final body weight and weight gain were lower and the feed conversion ratio was higher in fish cultured under HSD compared to those cultured under LSD. The fish cultured under LSD and HSD had higher final body weight when administered dietary LEO compared to the fish that were fed the non-supplemented diet. Adding 1% LEO increased the intestinal villus height and muscular coat thickness (MT). The MT was lower in fish cultured under HSD compared to those cultured under LSD. The amylase and lipase activities were lower in the fish cultured under HSD than in those cultured under LSD. However, LEO addition increased the lipase activity in fish cultured under LSD and HSD. Fish cultured under HSD showed lower immune/antioxidant indices (lysozymes, nitric oxide, complement 3, catalase, superoxide dismutase, and glutathione-S transferase) than those cultured under LSD. However, LEO addition significantly increased the immune response and antioxidant activity in fish cultured under LSD and HSD (P < 0.01). The level of expression of the IL-1β, IL-6, IL-8, NF-kB, and TLR-4 B genes was upregulated in the LSD + LEO1, LSD + LEO0.5, and HSD + LEO1 groups. The expression of TGF-β and IL-10 was upregulated in fish that received 1% and 0.5% LEO, irrespective of whether they were cultured under LSD or HSD. The level of expression of apoptosis-related genes (caspase 3 and BAX) was upregulated in the HSD + LEO0 group and modified by the addition of LEO in their diet. The immunoexpression of NF-kB and IL-1β after bacterial challenge increased in the tissues of fish cultured under LSD and HSD after LEO was administered. These results indicated that the dietary addition of 1% LEO mitigated the harmful effects of HSD on the growth, immunity, antioxidant activity, and disease resistance of the Nile tilapia. [ABSTRACT FROM AUTHOR]

Legal restrictions and consumer trends are contributing to the growing movement for fish welfare. Therefore, the aquaculture sector is a means of reducing animal stress and enhancing physiological state, which raises financial profits. Feed additives have therefore been suggested as possible dietary stress alleviation. In this trend, a 75-day feeding trial was conducted to evaluate the effects of three organic acids (formic acid (FA), lactic acid (LA), and commercial organic acids mix (COM)) as dietary additives in Nile tilapia (Oreochromis niloticus) reared under a stressful condition (unchanged water). Fish (weighing 3.95 ± 0.05 g) were randomly housed into eight groups (n = 210 fish/group; 70 fish/replicate; 3 replicates/group). The first (negative control) and second (positive control) groups were fed a basal diet without additives and with water exchange at 20% of the water volume every 2 days for the first group and without water exchange for the second. The other six groups (FA1, FA2, LA1, LA2, COM1, and COM2) were fed basal diets supplemented with OAs at two doses (1 and 2%) without water exchange during the trial. The results revealed that fish kept without water exchange (positive control) had the highest level of water-unionized ammonia and nitrite and a marked decline in growth performance (weight gain and specific growth rate). The unchanged water induced substantial decreases in the hematological profile (white and red blood cell count, hemoglobin value, and hematocrit %), protein profile indices (total protein, albumin, and globulin), and antioxidant-immune response (superoxide dismutase, catalase, lysozyme, and total immunoglobulin M). In addition, the biochemical indices (glucose, creatinine, urea, alanine aminotransferase, and aspartate aminotransferase) and lipid peroxide (malondialdehyde) were substantially increased in the positive control group. In addition to that, marked and severe histopathological alteration in the gills, liver, and intestine including hyperplasia, hemorrhage, and degenerative and necrotic changes that were associated with desquamation and sloughing were obvious in the PC group. Dietary LA1 significantly enhanced (P < 0.05) the overall measured indices; meanwhile, the dietary FA and COM recorded the worst results. Overall, our findings demonstrate that the unchanged water negatively affected the growth and physiological functions of Nile tilapia. Dietary incorporation of organic acids did not protect the fish from these hazards except the LA (1%). The latter can reduce nitrogenous compounds, enhance immune response, and alleviate these alterations for the sustainable aquaculture industry. [ABSTRACT FROM AUTHOR]

The current trial was designed to evaluate the positive impacts of different feed additives singly or in combination on the growth performance, nutritional parameters, intestinal histology, and gene expression of some growth and fat metabolism-related genes in the liver tissue of Nile tilapia. The experimented fish were allocated into eight groups in a glass aquarium (10 fish/aquarium in triplicate) with Pediococcus acidilactici, nanozeolites, and/or medium-chain fatty acid additives. The studied treatments were control (T0), nanozeolite (T1), Pediococcus (T2), medium-chain fatty acid (T3), nanozeolite + Pediococcus (T4), nanozeolite + medium-chain fatty acid (T5), Pediococcus + medium-chain fatty acid (T6), and nanozeolite + Pediococcus + medium-chain fatty acid (T7). The results of the growth and nutritional parameters (i.e., final body weight, total weight gain, feed intake, specific growth rate, feed conversion ratio, and protein efficiency ratio) of tilapia-fed diets supplemented with Pediococcus, nanozeolites, and medium-chain fatty acids improved, but the combination of these additives was significantly more effective. Moreover, expression of growth hormone receptor 1 gene was upregulated (P ≤ 0.05) in T7 fish when compared with T0, other groups showing intermediate values. Expression of insulin-like growth factor-1 was upregulated (P ≤ 0.05) in T5, T6, and T7 fish when compared with the other groups. The expression of the fatty acid-binding protein was higher in T6 and T7 fish (P ≤ 0.05) when compared with T0, T1, and T3 fish. In conclusion, combined additives had significant effects on improving growth and regulating growth-related genes. [ABSTRACT FROM AUTHOR]

Ectoparasites Dactylogyrus spp. mainly infest fish gills and severely damage the host's gill tissues. Correspondingly, the explanation of the interaction of fish with Dactylogyrus spp. infection is still insufficient. The present study describes the changes in hemato-biochemical, immune, antioxidant, genotoxic, and pathological indices response of Nile tilapia (Oreochromis niloticus) severely (n > 50), mildly infected (n = 1–50), and uninfected with Dactylogyrus spp. Data showed the adverse effect of hemato-biochemical indices in infected fish compared to uninfected, notably in severely infected O. niloticus. Compared to uninfected fish, there is a significantly decreased serum lysozyme and complement C3 and increased IgM and phagocytic activity along with significant upregulation of (COX-2), (IL-1β), (TNF-α), and (IL-10) genes in infected fish partially, in severely infected fish. Concisely, indices of antioxidants in the liver and gills marked an increased level of MDA in the infected fish compared to the uninfected fish. Conversely, levels of SOD, CAT, and GSH were decreased significantly with damaged DNA in the gills and liver of infected groups, particularly in severely infected (P < 0.05). Histopathologically investigating livers and gills in infected Nile tilapia indicated damaging and degenerative alterations, particularly with severe infection. Findings showed that Dactylogyrus spp.–infected Nile tilapia were effective in improving our knowledge of fish-pathogen interactions, which may be essential for fish defense against parasite infection. [ABSTRACT FROM AUTHOR]

The study aimed to investigate the impact of administering the antibiotic florfenicol (FFC) through dietary means on Oreochromis niloticus. The experiment involved exposing the fish to FFC at doses 0–10 times the therapeutic dose of 15 mg/kg biomass per day for 10 consecutive days. The group receiving the therapeutic dose showed 100% survival on the 10th day of dosing. Histological analysis revealed dose‐dependent changes in the spleen, including an increase in sinusoidal space, splenic necrosis, white pulp proliferation, splenitis, and red pulp hemorrhages. Additionally, there was an exponential rise in leukocyte counts accompanied by a significant decrease in erythrocyte counts, indicating the development of anemia due to FFC. The observed splenic histological damage, along with increased erythrophagia, erythro‐membrane breakage, and poikilocytosis, highlighted the splenotoxic and hemotoxic effects of FFC at higher doses. Importantly, these toxic effects showed considerable reduction upon discontinuation of FFC dosing. The study emphasized the need to consider FFC‐induced splenotoxic and hemotoxic outcomes in O. niloticus during its application in aquaculture. [ABSTRACT FROM AUTHOR]

This study examines the use of dragon fruit peel (DFP) powder as a dietary supplement on growth performance, immune responses, and gene expression of Nile tilapia, Oreochromis niloticus, cultured within biofloc systems. A total of 300 Nile tilapia fingerlings (14.64 ± 0.09 g) were subjected to five dietary treatments, with DFP added to a basal diet at doses of 0, 20, 40, 80, and 160 g kg−1 DFP. Growth and immunological responses were assessed after 4 and 8 weeks of feeding, and the transcriptional level of immune and antioxidant‐related genes was measured after 8 weeks. Fish fed diets containing DFP exhibited significantly greater weight gain, faster growth, and enhanced levels of key indicators of immunity than control fish (p < 0.05). A diet containing 40 g DFP kg−1 produced the best result in terms of growth, enhanced immune response indicators in skin mucus and blood serum, and the upregulation of IL‐1, IL‐8, LBP, GPx, GST‐α, and GSR expression (p < 0.05). Based on the quadratic regression analysis, the optimum concentration of DFP was 80 g kg−1. These findings collectively suggest that powdered DFP may serve as a promising feed supplement for Nile tilapia raised in biofloc systems. [ABSTRACT FROM AUTHOR]

Bagega community is an artisanal mining community with a history of Pb poisoning. The community is served by a small lake as an important source of water for cattle watering, irrigation, washing, and fishing among other uses. The concentration of Cd, Cr, and Pb in soil and plants at the bank, surface water, sediment, and fish of the lake were analysed using Agilent 4210 MP-AES machine after microwave digestion using the Advanced Microwave Digestion System model (Ethos easy). The concentrations of Pb and Cr in water from Bagega Lake were found to be above the WHO acceptable limits. This presents a health risk to humans and other animals that utilize directly or indirectly utilize the water in the lake. Catfish (Clarias anguillaris) and Tilapia (Oreochromis niloticus) had higher Pb and Cr concentrations in the gills than in the liver and h muscle (flesh). The concentrations of Cr, Cd and Pb of soils in the bank and sediment of Bagega Lake were below the WHO acceptable limits. A total of thirteen (13) plant species belonging to seven (7) families were identified to be dominant around the Bagega Lake during the time of study and they all show the potential of bioaccumulation of Cr and Pb based on their BCF. [ABSTRACT FROM AUTHOR]

Hexaflumuron (HEX) insecticide is widely used in agriculture practices to fight crop insects. The toxicological effect of HEX on Nile tilapia (Oreochromis niloticus) was investigated in this study. Two hundred and forty fish (35.50 ± 1.45 g) were divided into six groups in four replicates (40 fish/group; 10 fish/replicate) and were exposed to six distinct HEX concentrations (0, 2, 4, 6, 8, and 10 mg L−1) for 96-h. The 96-h lethal concentration 50 (96-h LC50) of HEX was calculated to be 7.19 mg L−1. The fish exhibited reduced surface and middle swimming, aggressiveness, and tail-spreading behaviors with increasing bottom swimming and resting patterns after HEX exposure. HEX exposure resulted in body bleeding and fin rot. The erythrogram (red blood cell count, hemoglobin, and packed cell volume %) was significantly reduced with increased mean corpuscular volume by HEX exposure. HEX exposure decreased the white blood cells (WBCs) and differential WBC counts. Acute HEX exposure raised 8-hydroxy-2-deoxyguanosine level while lowering brain acetylcholine esterase activity. HEX exposure caused hepato-renal dysfunction and increased stress-related parameters (glucose and cortisol). Exposure to HEX reduced the immune responses (lysozyme, nitric oxide, immunoglobulin M, and complement 3). A substantial decrease in the antioxidant variables (reduced glutathione content and catalase) with increasing the malondialdehyde was noted by HEX exposure. Moreover, histopathological changes resulted from HEX exposure in the gills, liver, kidney, and spleen. These results indicate that HEX exposure induced behavioral changes, hepato-renal dysfunction, and immune-antioxidant disruption, indicating a possible physiological disruption in O. niloticus. [ABSTRACT FROM AUTHOR]

The study investigated the impact of N-acetyl cysteine on growth, immune response, and antioxidant activity in tilapia (Oreochromis niloticus). Fish were reared at three densities (1.50, 3.00, and 4.50 kg/m3) with four levels of N-acetyl cysteine supplementation (0, 2, 4, and 6 mg/kg) over 60 days. Better growth was observed at low density, but at all densities, fish fed the highest N-acetyl cysteine level (6 mg/kg) showed improved growth. Chemical composition of fish and activity of amylase, lipase and protease in all treatments were noted to be insignificant. The levels of antioxidant enzymes (catalase, superoxide dismutase and glutathione peroxidase) and cortisol in HD treatments were high as compared to LD and MD treatment. However, fish fed with N3 diet in each density treatment showed the lowest level of antioxidant enzymes as well as cortisol. Similarly, the levels of malondialdehyde were noted to be high at HD treatments as compared to that in LD and MD. Its levels were lower in fish fed with N3 diets in all density treatments. Expression of somatostatins-1 did not increase in MD and HD treatments in response to high stocking density when compared with LD treatment. However, pro-opiomelanocortin-α level was reduced after N3 diet in HD treatment and interleukin 1-β expression increased after N3 supplement in HD treatment. In conclusion, N-acetyl cysteine supplementation improved growth and antioxidant response in tilapia. The most optimum dose of N-acetyl cysteine was noted to be 6 mg/kg at high stocking, suggesting the potential role of this nutraceutical in tilapia intensive culture. [ABSTRACT FROM AUTHOR]

The efficacy of herbal supplements in mitigating heavy metals (HMs) toxicity was investigated using a widely grown fish, the Nile tilapia (Oreochromis niloticus). The experiment was conducted over two phases: during the stress phase, the experimental fishes were exposed to sub-lethal concentrations of HMs, including lead, cadmium, zinc, and copper for 15 days; following which during the feeding phase, herbal supplements were given for 70 days to ameliorate their effects. Seven groups were established: the control negative group (CON−ve), control positive group (CON+ve, without any treatment), and five groups with supplementation of 1% turmeric (TUR), cinnamon (CIN), ginger (GIN), garlic (GAR), and their mixture (MIX), respectively. A total of 315 fishes were distributed evenly in experimental tanks (15 fishes per tank, in triplicates). The results revealed that exposure to HMs led to significant (p < 0.05) alterations in all the tested parameters, i.e., liver damage and growth reduction. The herbal supplements, especially the MIX groups, ameliorated the harmful effects of HMs and restored fish growth, digestibility, carcass composition, and liver health. In conclusion, the study demonstrated that the herbal supplements were effective in reducing the HMs-linked toxicity in Nile tilapia. Future studies pertaining to the mechanisms facilitated by the various herbal bioactive substances-linked tolerance to HMs in fishes are warranted. [ABSTRACT FROM AUTHOR]

As an omnivorous fish, wild tilapia feed on both animal and plant foods, depending on what is available. To understand the nutritional function of the gut microbiota of tilapia, we used shotgun metagenomic sequencing, untargeted metabolomics analysis, and 16S rRNA gene sequencing to study the metabolites and gut microbial communities in tilapia eating different diets (artemia nauplii in the carnivorous diet; plant‐based pelleted feed [PBP] in the herbivorous diet; and a mixture of these two in the omnivorous diet). A total of 225 Nile tilapia (Oreochromis niloticus) were cultured in nine 1500 L outdoor tanks, with three replicate tanks per diet and 25 fish per tank. β‐diversity analysis revealed that there was no significant difference in microbial structure between the three diets. However, significant differences were detected in gut metabolites. The abundance of the core bacteria in tilapia intestine (genus Cetobacterium) increased significantly when an omnivorous diet was fed. Cetobacterium abundance was significantly correlated to some differential metabolites including glucose and amino acids, and significantly correlated to pathways of carbohydrate and amino acids metabolism, identified by metagenome analysis. Metagenomic binning produced seven Cetobacterium MAGs with the completeness >50% and contamination <10%, in which genes related to the above metabolites and metabolism pathways were identified. All seven MAGs contained CAZymes that could act on distinct carbohydrates, providing highly diversified capabilities to this genus to cope with both animal and plant glycans. These tilapia fed with an omnivorous diet also showed increased growth. The differential intestinal metabolites aspartate, isoleucine, ornithine, proline, nicotinate, and NAD+ could be related to the increased growth. Our results expanded the understanding of how tilapia have adapted to an omnivorous diet and may provide knowledge for improving aquaculture management. [ABSTRACT FROM AUTHOR]

This study investigates the immunological and growth effects of Vitamin C and Zinc supplementation on Nile tilapia (Oreochromis niloticus) subjected to cold water stress. Nile tilapia fingerlings were housed in eight 20-gallon tanks at Purdue University, acclimated to 26 ± 2°C water conditions before the experiment. The tilapia was divided into groups with varying water temperatures and feed supplements: control fish in warm water, and experimental groups in cold water with increased levels of Vitamin C and Zinc. Stress was induced by lowering the water temperature to 15 ± 2°C in four tanks, while the remaining tanks were kept at the optimal growth temperature. Results demonstrated that Vitamin C and Zinc supplementation significantly enhanced immune response and muscle regeneration in cold-stressed tilapia, allowing them to achieve growth rates comparable to those of control fish in optimal warm water conditions. These findings highlight the potential benefits of combined Vitamin C and Zinc supplementation in improving the immune response and growth performance of tilapia under suboptimal temperature conditions. [ABSTRACT FROM AUTHOR]

ABSTRACT Water temperature is a critical environmental parameter that significantly influences fish metabolism. This study assessed the metabolism of florfenicol (FF) in tilapia (Oreochromis niloticus) at water temperatures typical of tropical and subtropical regions. Fish were treated with FF by oral administration of a dose of 10 mg kg−1 bw for 10 consecutive days. Fish fillet, liver, and kidney were sampled during the treatment phase (1, 5, and 10 days) and posttreatment (1, 2, 3, and 5 days after the last FF administration). FF, florfenicol amine (FFA), monochloro florfenicol (FFCl), and florfenicol alcohol (FFOH) were determined in the sampled tissues using a validated LC–LC–MS/MS method. The highest FF, FFA, and FFOH concentrations were determined on day 5 during the treatment phase. For FF, the concentration order is kidney > liver > fillet, while for the metabolites FFOH and FFA, the order is liver > kidney > fillet. In fillet and liver, the concentrations of FFOH were higher than the FFA concentrations, indicating that FFOH was the primary metabolite in these tissues. FFCl was only quantified at concentrations lower than 90 μg kg−1 in all tissues. The results indicated that FF can be readily absorbed and rapidly eliminated in tilapia cultivated in warm water environments. This study revealed FFOH as the primary and most persistent metabolite in tilapia farmed in warm water, followed by FFA. [ABSTRACT FROM AUTHOR]

Microplastic (MP) ingestion through fish consumption is a concern for human exposure. While the presence of plastic particles in fish tissues has been documented worldwide, information on microplastic concentrations in edible tissues, especially those smaller than 10 µm, remains scarce. Spectrometric techniques provide a complementary analytical tool to measure MP mass for human exposure studies without intrinsic size limitations; however, their application to fish analysis is limited. In this study, we utilized pyrolysis gas chromatography–mass spectrometry (Py-GC–MS) for the identification and quantification of MPs in fish muscle tissues. Two sample preparation methods, pressurized liquid extraction, and chemical digestion, were tested for compatibility with Py-GC–MS analysis. An analytical method using chemical digestion was validated for analyzing particles ≥ 0.7 µm for 4 polymer types: polypropylene, polyethylene, polystyrene, and polymethyl methacrylate. The developed method was applied to 24 adult Nile tilapia (Oreochromis niloticus) samples from a recirculating aquaculture system. MPs were detected in 42% of the samples, with an average concentration of 0.14 ± 0.32 µg/g, while high variations within subsamples were observed. Our findings reveal trace amounts of MPs in edible fish tissues from aquaculture, highlighting the potential risk of microplastic ingestion through fish consumption. This underscores the need for further risk assessments to evaluate the impact on human health and to develop appropriate mitigation measures. [ABSTRACT FROM AUTHOR]

The effects of nanoscale synthetic zeolite powder (NZeP) levels in diet on water quality, growth performance, muscle proximate composition, and some blood biochemical indices of Nile tilapia (Oreochromis niloticus) fingerlings were evaluated in a 60‐day experiment. One hundred eighty fish with an average weight of 5.91 ± 0.45 g were distributed in three different groups of control (basal diet without NZeP), NZP0.5% (basal diet + 0.5% NZeP), and NZeP1% (basal diet + 1% NZeP) with triplicate. The zeolite particles were characterized via field emission scanning electron microscopy coupled with X‐ray energy dispersive spectroscopy (FE‐SEM/EDS), dynamic light scattering (DLS), and X‐ray diffraction (XRD) techniques. The results revealed that the total ammonia nitrogen (TAN) concentration in the NZeP dietary groups decreased compared to the control group after the 20th day of the experiment (p < 0.05). The TAN concentration in the NZeP1% group was lower than in the NZeP0.5% group on days 50 and 60 (p < 0.05). The final weight, weight gain, and average daily gain parameters were lower in the fish fed on NZeP1%‐supplemented diet than in other dietary groups (p < 0.05). The feed conversion ratio value decreased in the NZeP dietary groups compared to the control (p < 0.05). The lowest FCR value was recorded in the NZeP1% dietary group (p < 0.05). The muscle crude protein content increased in the fish fed on diet supplemented with NZeP1% in comparison to the control (p < 0.05). The aspartate aminotransferase (AST) concentration decreased in the plasma of fish fed on NZeP‐supplemented diets compared to the control (p < 0.05). The plasma glucose concentration was lower in the NZeP1% dietary group than the control (p < 0.05). In conclusion, the adding nanozeolite powder at a level of 1% to diet had positive effects on water quality, the growth performance, and muscle proximate composition of Nile tilapia fingerlings. [ABSTRACT FROM AUTHOR]

The present study evaluated the use of green-synthesized selenium nanoparticles (SeNPs), using the microalgae Pediastrum boryanum as a diet additive in aquaculture to improve the growth performance, health, and immune response of Nile tilapia. Nile tilapia were fed different concentrations of green SeNPs (79.26 nm) as follows: 0, 0.75, and 1.5 mg/kg of SeNPs for 8 weeks. Following the trial, growth performance, biochemical indices, antioxidant and pro-inflammatory cytokine-related genes, and tissue histological examinations were performed. The study showed that SeNPs significantly improved (P < 0.05) growth performance and innate immune parameters (P < 0.001, IgM, and lysozyme) at both supplemented doses compared with the control. The protein profile and liver function enzymes were normal compared with those in the control group (P > 0.05). Serum malondialdehyde and superoxide dismutase levels were not significantly changed, while reduced glutathione and catalase were significantly enhanced (P < 0.01, P < 0.05) in the SeNPs 1.5 mg/kg compared to the control group. No inflammatory response was detected upon SeNP supplementation, as indicated by the absence of changes in the expression of pro-inflammatory cytokine genes. The earlier assays' results were histopathologically evidenced, where hepatic and splenic tissue architectures in SeNPs groups did not reveal any deviation from the control group. Our findings indicate that green selenium nanoparticles can potentially improve the growth and immunological response of Nile tilapia, offering opportunities for incorporating health benefits into functional foods and nutraceuticals, which corresponds to the increasing consumer interest in eco-friendly, environmentally sustainable dietary supplements. [ABSTRACT FROM AUTHOR]

This study evaluated the impact of increasing dietary β‐mannanase (BM) supplementation (Natupulse TS, BASF, Ludwigshafen am Rhein, Germany) on fecal viscosity and pH, apparent digestibility coefficients (ADCs) of energy and nutrients, including amino acids, fecal nutrient loss in contents of soybean meal (SBM)‐based diets fed to juvenile Nile tilapia, Oreochromis niloticus. A total of 504 fingerlings (initial body weight of 31.5 ± 4.2 g) were randomly distributed into 24 aquaria (70 L each) in a completely randomized design using six dietary treatments and four replicates of 21 fish per aquarium. Fish were fed diets containing BM at 0, 1600, 3200, 4800, 6400, and 8000 TMU (thermostable endo‐1,4‐BM units) kg−1 and hand‐fed six times a day until apparent satiety for 30 days. Chromium oxide was employed as an indigestible marker. The ADC of gross energy, crude protein, crude lipids, and essential amino acids exhibited a quadratic effect with the maximum point in fish fed 4818, 4722, 4615, and 4816 TMU kg−1 BM, respectively. The digestible energy (DE) content of diets presented a quadratic effect, and the maximum point was obtained in fish fed 4803 TMU BM kg−1 diet, which improved the DE content by +1.2 MJ kg−1 relative to the BM‐unsupplemented diet. The fecal pH, fecal viscosity, organic matter loss, and nitrogen loss presented a quadratic effect with the minimum point in fish fed 4810, 4839, 4750, and 4801 TMU BM kg−1 diet, respectively. Principal component analysis indicated that dietary BM at 4800 and 6400 TMU BM kg−1 diet was associated with improvements in the ADC of gross energy, crude protein, and crude lipids. In conclusion, including 4803 TMU BM kg−1 diet effectively improves DE content and optimizes nutrient digestibility and feces pH and viscosity in Nile tilapia fed an SBM‐based diet. [ABSTRACT FROM AUTHOR]

Curcumin, the main polyphenol component of turmeric powder, has garnered increasing attention as an effective supplement in fish diets. A comparative trial was conducted to evaluate the impacts of dietary supplementation with different forms of curcumin (free, in combination, or nanoparticles) on hemato-biochemical parameters, reproductive capacity, and related gene expressions of red tilapia (Oreochromis niloticus x O. mossambicus) broodstock. Fish (n = 168) were fed an isonitrogenous (30% CP), isocaloric (18.72 MJ kg − 1) diet containing basal diet (Control), 60 mg kg-1 of either free curcumin (Cur), curcumin/nano-curcumin blend (Cur/NCur), or nano-curcumin (NCur) for 56 days. Red tilapia broodstock (155 ± 5.65 g) were stocked at a male: female ratio of 1:3. Blood samples and gonads were collected to assess hemato-biochemical parameters, reproductive capacity, and related gene expression at the end of the feeding trial. The results indicated that the values of hematological parameters (RBCs, WBCs, hemoglobin), total protein, albumin values, and reproductive hormones (T, LH, and FSH) were significantly increased, while liver function enzymes were decreased in the NCur group (P < 0.05). Reproductive performances (GSI, gonad maturation, total number of fry per female) were significantly improved in the NCur group compared with those in other groups (p < 0.05). The expression of reproductive genes (CYP19A1A, FSHR, LHR, FOXL2A, ESR1, ESR2A, and PGR) were significantly up‐regulated in the gonads of fish fed NCur. Collectively, feeding red tilapia diets containing NCur led to noticeably better results followed by Cur/NCur blend, then free Cur compared to the control diet. These results indicate the superiority of NCur over its free or blended form, suggesting that a diet containing about 60 mg/kg of NCur is beneficial for enhancing hemato-biochemical parameters, improving reproductive performance, and enhancing the gonadal architecture of red tilapia. [ABSTRACT FROM AUTHOR]

AbstractThe cultivation of tilapias, the third most farmed fish group globally, has been rapidly growing, especially in Southeast Asia. This surge in tilapia farming intensification has led to increased use of antibiotics to control bacterial diseases. This study investigated the safety implications of administering graded doses of enrofloxacin (ENF) at 0 (control), 10, 30, 50 and 100 mg/kg biomass/day orally to Oreochromis niloticus. The 43-day study comprised 7 days of pre-dosing, 15 days of ENF-dosing, and a 21-day recovery period with a periodical assessment of the biological responses of fish. The results revealed that the overdosed groups experienced up to 21% reduction in feed consumption, 11% mortalities, and adverse impacts on hematology, including a decrease in erythrocytes, and monocytes and an increase in leukocytes, thrombocytes, lymphocytes, and neutrophils. Haematological indices like mean corpuscular volume and mean corpuscular hemoglobin decreased, while mean corpuscular hemoglobin concentration increased. The plasma biochemical parameters including glucose and liver and kidney enzymes unveiled a significant dose- and time-dependent increase, while calcium and chloride levels decreased. Erythrocytes displayed several erythrocyte cellular and nuclear abnormalities. The frequency of micronucleus increased with dose and time, suggesting potential genotoxicity of ENF. Additionally, a dose-dependent increase in residues in the tissues with the highest accumulation in muscle was documented. Nevertheless, the recovery of the measured parameters upon dose termination indicated that the ENF-induced alterations are reversible. The study affirmed the safety of ENF at the recommended dose (10 mg) in O. niloticus and their adoptive responses to higher doses. [ABSTRACT FROM AUTHOR]

Tilapia and lettuce are the most frequently used combination among aquaponics producers, hobbyists, and educators. Therefore, this literature review aims to aggregate the knowledge on the current status of tilapia/lettuce production and identify research gaps. Among the 40 reviewed publications, 72.5% used Nile tilapia, 17.5% used red, 2.5% used red Mozambique, 5% used rocky mountain strain, and 5% of the articles stated that they used tilapia without reporting the species. Tilapia initial density used ranged from 0.34 to 28.4 kg/m3, which depended on the purpose of the study, experimental size, and design. For the hydroponic unit, 55% of the publications utilized deep water culture (DWC), 35% utilized nutrient film technique (NFT), and 10% utilized media bed (MB). The optimum ratio between fish feeding rate and plant growing area (60 g of feed/day/m2) was originally calculated at the University of Virgin Island and published in 1988 using Bibb lettuce. This recommended ratio has been used by farmers and researchers as a rule of thumb for years. However, this recommended ratio did not take into account other factors such as fish species, protein content of the diet, plant species/variety, plant density, biological filtration, and airflow in the grow bed. Hence, the current review suggests that the fish‐to‐plant ratio, fish density, and flow rate in the aquaponic systems needs to be reevaluated. As there is a thermal preference mismatch between tilapia and lettuce, there is a need to evaluate the optimum temperature for both to obtain the highest growth performance. Nowadays, it is believed that the farmed stocks' genetic quality needs to be regularly enhanced and protected. Consequently, feeding frequency, feeding amount, and stocking densities in aquaponic systems should be continuously reevaluated with the improved strains of tilapia as well as heat‐tolerant varieties of lettuce. [ABSTRACT FROM AUTHOR]

Tilapia, a widely farmed aquaculture fish, produces substantial waste, including viscera that contain extracellular matrix (ECM) utilized as a biomaterial for tissue regeneration applications. Extracting ECM from viscera requires a specific decellularization method, as no standardized protocol exists. This study performed three decellularization methods: sonication, orbital shaking at room temperature, and agitation at 4°C, using SDS and TX100 at concentrations of 0.1% and 0.3%. The effectiveness of each method was assessed through H&E staining, dsDNA quantification, and SEM imaging to verify cellular content removal and ECM structure preservation. Additional analyses, including ATR‐FTIR, SDS‐PAGE, protein quantification, HPLC, and detergent residue tests, were performed to examine functional groups, collagen composition, protein content, amino acid profiles, and detergent residues in the decellularized samples. The results of H&E staining showed a significant reduction in cellular components in all samples, which was confirmed through DNA quantification. Sonication with 0.3% SDS achieved the highest DNA removal rate (96.5 ± 1.1%), while SEM images revealed that agitation at 4°C with 0.3% TX100 better preserved ECM structure. Collagen was present in all samples, as confirmed by ATR‐FTIR analysis, which revealed pronounced spectral peaks in the amide I, II, III, A, and B regions. Samples treated with agitation at 4°C using 0.1% SDS exhibited the highest protein content (875 ± 15 µg/mg), whereas those treated with TX100 had lower detergent residue. Overall, the decellularization methods effectively reduced DNA content while preserving ECM structure and components, highlighting the potential of tilapia viscera as bioscaffolds and offering insights into utilizing fish waste for high‐value products. [ABSTRACT FROM AUTHOR]

Fish sex is largely influenced by steroid hormones, especially sex hormones. Here, we established a steroid hormone-free genetic model by mutation of cyp11a1 in Nile tilapia, which was confirmed by EIA assay. Gonadal phenotype and transcriptome analyses showed that the XX mutants displayed sex reversal from female to male but with defective spermatogenesis. Despite the sex reversal, the aromatase encoding gene cyp19a1a was continuously expressed in the gonads of the XX mutants, which might be caused by androgen deficiency. Whole-mount fluorescence in situ hybridization and transcriptome analysis showed that the gonads of the XX mutants firstly developed towards ovary but shifted to testis between 10 to 15 days after hatching. Detailed expression analysis of key sex differentiation pathway genes foxl3 and dmrt1 combined with apoptosis analysis revealed transdifferentiation of germ cells from female to male during sex reversal. Rescue experiments showed that both P5 and E2 treatment rescued the sex reversal of cyp11a1 mutant XX fish. Overall, our results revealed a transient ovary-like stage and transdifferentiation of germ cells from female to male in the early gonads of the steroid hormone-deprived cyp11a1 mutant XX fish. Revealing of a transient ovary-like stage and transdifferentiation of germ cells from female to male in the early gonads of the XX fish after steroid hormone-deprivation. [ABSTRACT FROM AUTHOR]

Summary This study aimed to isolate and characterise zinc‐chelating peptides from tilapia (Oreochromis niloticus) protein hydrolysate. The hydrolysate was fractionated using a multi‐ultrafiltration technique, yielding peptide fractions with molecular weights between 0.5 and 5 kDa. These fractions were further purified using immobilised metal ion affinity chromatography (IMAC‐Zn2+) and reverse high‐performance liquid chromatography (RP‐HPLC). Among the fractions obtained, the peptide fraction F211 exhibited a zinc‐binding capacity of 76.26 ± 2.46 mg g−1. Sequence analysis indicated that zinc binding occurred at amino acids on the F21 peptide and at valine or glutamate residues on the F22 peptide fraction. Structural characterisation revealed that amino nitrogen and oxygen atoms from carboxylate groups were the primary binding sites for Zn2+. Additionally, the zinc–peptide complex demonstrated strong thermal stability, which is significant for potential applications in food processing and storage, where maintaining the integrity of nutritional supplements under varying temperature conditions is crucial. These findings provide a feasible approach for the separation and purification of zinc‐binding peptides from tilapia protein hydrolysates and contribute to the understanding of the binding mechanisms between zinc and peptides. [ABSTRACT FROM AUTHOR]

In the past decade, the increasing distribution of pollutants in the aquatic environment has been observed, causing integrative effects on fish. Likewise, due to anthropogenic activities, the southern gulf of Lake Tana is an impacted region, and the production of Nile tilapia fish is reduced. For this reason, the aim of this study was to conduct a histopathological-based study of 48 Nile tilapia fishes' health status at the southern gulf of Lake Tana and aquaculture using a cross-sectional study from February 2023 to May 2023. The study evaluated the histopathology of the gill, liver, gonads, and spleen organs using descriptive statistics accompanied by a 2 × 2 contingency table and t-test analysis. During the study, different histological alterations were detected, and the numbers of fish affected by a specific histological alteration were presented as percentage prevalence; hence, from the total fish examined, hyperplasia (54.15%), followed by pigment deposits (52%), hemorrhage (50%), and immune cell infiltration (50%), respectively, were the most frequently detected alterations. However, Nile tilapias from the southern gulf of Lake Tana were 1.4 (odds ratio) times more likely to show histopathological alterations than those from aquaculture, although statistically, was not significant (p > 0.05). In addition, the study found the mean value of the fish index (95.3) and regressive indices of the gill (13.6), liver (14.8), and gonad (12.3); moreover, the inflammatory indices of the spleen organ (11.3) and mean severity grade value of the gill (2.35) and gonad (1.7) organs, respectively, were obtained from the southern gulf of Lake Tana, and all those values were significantly higher (p < 0.05) from this site as compared to the aquaculture. In general, it has been found that tilapias from the southern gulf of Lake Tana showed higher pathological severity as compared with aquaculture. Among the four target organs evaluated, liver organs were observed to be the most damaged, while gonads were the least impacted organs. Therefore, it has been concluded that tilapia fish are living in abnormal conditions, so to ensure a sustainable fishery, water pollutant sources from Bahirdar city must receive proper attention, and future studies should consider age differences, seasonal variation, and the detection of specific pollutants. [ABSTRACT FROM AUTHOR]

Sophora flavescens is considered to be of various medicinal and economic importance. Previous studies have shown that it has antibacterial, antioxidant, and immune‐enhancing functions. To explore the full potential of S. flavescens in fish feed development, we investigated the effects of different levels of S. flavescens added to the diet on the growth performance, haematological indices, and the intestinal bacterial community of Nile tilapia (Oreochromis niloticus). The feeding trial lasted for 56 days, and the initial weight of the fish was 40.00 ± 5.00 g. Nile tilapia were randomly divided into six groups: a control group (CN) and five S. flavescens supplementation groups (0.02%, 0.04%, 0.08%, 0.16%, and 0.3% [w/w] of S. flavescens in diet). The growth performance of fish increased first and then decreased with the increase of S. flavescens supplemental level. Compared with other experimental groups, the growth performance of fish supplemented with 0.08% S. flavescens was significantly improved (p < 0.05). Haematological indices exhibited that erythrocyte (RBC), along with leucocyte (WBC) indices, exhibited a secondary trend of increasing and then decreasing with the increase of S. flavescens, reaching the highest level at 0.08% (p < 0.05). However, mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH), and mean corpuscular haemoglobin concentration (MCHC) exhibited a secondary trend of first decreasing and then increasing with the increase of S. flavescens and reached the lowest value at 0.08% (p < 0.05). Compared with the CN, alkaline phosphatase (AKP) significantly decreased and changed when the additional amount of S. flavescens was 0.04% in each treatment group (p < 0.05). In another way, the gut microbial profiles revealed that Bacteroides dominated the gut communities, and compared with the control group, two uncultured bacteria were suppressed. In addition, when the supplemental level of S. flavescens was more significant than 0.04%, the proliferation of Arcobacter cryaerophilus, Solibacillus silvestris, and Escherichia sp. in the gut of Nile tilapia was promoted. The results revealed that S. flavescens, as an additive to the Nile tilapia diet with levels ranging from 0.04% to 0.08%, can enhance the growth performance and immunity and promote the proliferation of intestinal beneficial bacteria of Nile tilapia. [ABSTRACT FROM AUTHOR]

Sarmentosin (SA) and Quercetin (QC) are two active components of Sedum Sarmentosum Bunge, which is a traditional Chinese herbal medicine. This study aimed to investigate the role and regulatory mechanism of SA and QC in fatty liver of Genetic Improvement of Farmed Tilapia (GIFT) tilapia. GIFT tilapia were randomly divided into two groups with three replicates per treatment (30 fish in each replicate): normal diet group (average weight 3.51±0.31 g) and high-fat diet group (average weight 3.44±0.09 g). After 8 weeks feeding trial, growth index, lipid deposition, and biochemical indexes were measured. Lipid deposition, and lipid and inflammation-related gene expression were detected in a primary hepatocyte model of fatty liver of GIFT tilapia treated with SA or QC. Our results showed that high-fat diet caused lipid deposition and peroxidative damage in the liver of GIFT tilapia. The cell counting kit-8 assay results indicated that 10 μM SA and 10 μM of QC both had the least effect on hepatocyte proliferation. Moreover, both 10 μM of SA and 10 μM of QC showed lipolytic effects and inhibited the expression of lipid-related genes (FAS, Leptin, SREBP-1c, and SREBP2) in fatty liver cells. Interestingly, QC induced autophagosome-like subcellular structure and increased the expression of IL-8 in fatty liver cells. In conclusion, this study confirmed that SA and QC improved fatty liver caused by high-fat diet, providing a novel therapeutic approach for fatty liver of GIFT tilapia. [ABSTRACT FROM AUTHOR]

In fish species, there is limited analysis of signature transcriptome profiles at the single‐cell level in gonadal cells. Here, the molecular signatures of distinct ovarian cell categories in adult Nile tilapia (Oreochromis niloticus) were analysed using single‐nucleus RNA sequencing (snRNA‐seq). We identified four cell types (oogonia, oocytes, granulosa cell, and thecal cell) based on their specifically expressed genes and biological functions. Similarly, we found some key pathways involved in ovarian development that may affect germline–somatic interactions. A cell‐to‐cell communication network between the distinct cell types was constructed. We found that the bidirectional communication is mandatory for the development of germ cells and somatic cells in fish ovaries, and the granulosa cells and thecal cells play a central regulating role in the cell network in fish ovary. Additionally, we identified some novel candidate marker genes for various types of ovarian cells and also validated them using in situ hybridization. Our work reveals an ovarian atlas at the cellular and molecular levels and contributes to providing insights into oogenesis and gonad development in fish. [ABSTRACT FROM AUTHOR]

Water quality in land-based fish production can be controlled through either instantaneous water exchange or costly wastewater treatment followed by recirculation. Agricultural-aquaculture integration is an excellent alternative technique for reducing nutrient discharge levels, boosting profitability, and converting fish culture wastewater into valuable products. The current study employed a solar energy system to power two separate IMTA-aquaponics systems (Nutrient Film Technique, NFT, and Floating Raft Systems, FRS) for the cultivation of Nile tilapia, African catfish, thin-lipped grey mullet, freshwater crayfish, freshwater mussels, and a variety of vegetables. Tilapia and catfish were fed exclusively on diets under the IMTA system. All wastewater from tilapia and catfish ponds, both dissolved and solid, flows sequentially to ponds containing other cultivated species. The water then flows through the IMTA system's terminal point to the NFT and FRS systems before returning to the tilapia and catfish ponds, allowing complete control of the nutrient flow throughout this entire circular system. Two 147-day production cycles were concluded. The results from the second production cycle are reported. Total biomass gain for aquatic species in the IMTA system was 736.46 kg, compared to 145.49 kg in the tilapia and 271.01 kg in the catfish monoculture systems. The current IMTA system had a cumulative feed conversion ratio (FCR) of 0.90, while the FCRs for tilapia and catfish were 1.28 and 1.42, respectively. Nile tilapia and catfish consumed 571.90 kg of feed containing 25.70 kg of nitrogen (N) and 9.70 kg of phosphorus (P), reflecting, and gaining 11.41 and 3.93 kg of dietary N and P, representing 44.40 and 40.46% dietary N and P retention, respectively. In the IMTA system, the addition of mullet and prawn as detrivores aquatic animals improves dietary N and P utilization efficiency to 59.06 and 51.19%, respectively, while the addition of mussels as herbivore animals improves dietary N and P utilization efficiency to 65.61 and 54.67%, respectively. Finally, using FRS and NFT as hydroponic systems increased dietary N and P efficiency to 83.51% N and 96.82% P, respectively. This study shows that the IMTA-Aquaponic system, as a bio-integrated food production system, can convert the majority of fish-fed residues into valuable products suitable for desert, rural, and urban areas in impoverished and developing countries. [ABSTRACT FROM AUTHOR]

The present study was conducted to evaluate the effects of exposure to sublethal concentrations of cypermethrin on growth, phenotypic traits, and metabolic and antioxidant enzymes activities of monosex tilapia (Oreochromis niloticus). The median lethal concentration (LC50) of cypermethrin was initially ascertained to be 0.04 ppm after 12 h of exposure to three concentrations (0.04, 0.20, and 1.0 ppm) via the Probit analysis method. The sublethal exposures were obtained for 3 months at 0.0016, 0.008, and 0.04 ppm of cypermethrin. The growth performance, phenotypic traits, and enzymatic activity were analyzed. The research findings revealed a notable impact of cypermethrin on the growth performance of monosex tilapia, with a significant (p < 0.05) decrease in weight observed as the concentration increased. The experiment documented a significant change (p < 0.05) in the phenotypic traits of standard length, total length, tail length, trunk length, eye diameter, body area, and color patterns, but not dressing percentage. Furthermore, it was observed that the activities of amylase and protease in both the intestine and muscle decreased significantly (p < 0.05) with increasing concentrations of cypermethrin, except for amylase in the muscle, where no significant change was noted (p > 0.05). The results also demonstrated significant reductions (p < 0.05) in the activity of metabolic enzymes, specifically superoxide dismutase and catalase, following exposure to sublethal levels of cypermethrin. The study suggested that sublethal exposure of pyrethroid alters the growth, phenotypic traits, metabolic enzymes activities, and immunity of monosex tilapia. [ABSTRACT FROM AUTHOR]

This research examined the impact of incorporating cinnamon meal (CM), water cinnamon extract (CEX), and its combination on fish productivities, blood parameters and economic outcomes over 56 days. Five groups of fish were fed different diets: a control diet (D1), 1% cinnamon meal (D2), 1% water cinnamon extract (D3), combinations of 0.5% CM and 0.5% WCEX (D4), and 1% CM and 1% WCEX (D5). All diets were iso-caloric and iso-nitrogenous. Significant improvements in growth performances and feed utilization parameters were observed (P<0.05) in D5 (1% CM and 1% WCEX) compared to control or other treatments, with 100% survival in the D2, D4, and D5 groups, compared to 93.33% in D1 and D3. Feed conversion ratio improved with cinnamon-treated diets, and serum protein and globulin levels increased significantly, while cholesterol levels decreased. Body composition analysis showed a significant reduction in OM and CP, while DM, EE, ash, and GE content increased. The economic return improved in cinnamon-treated groups, though the percentage of profitable value decreased slightly. Diet costs were reduced, and net improvement over the control ranged from 2.32 to 8.82%. In conclusion, adding cinnamon meal and/or cinnamon water extract to fish diets impacted growth and feed efficiency positively, without negative effects. [ABSTRACT FROM AUTHOR]

Aquaculture is the fastest-growing sector of animal food production worldwide. However, many challenges face aquaculture farms, with two of the most critical being the high costs of production and the prevalence of diseases, which cause significant mortality, especially during the summer months. This study evaluated the effects of adding a commercial probiotic as a water additive for the Nile tilapia (Oreochromis niloticus) raised in semi-intensive earthen pond systems. The experiment was designed as a field study conducted on farms in various governorates. Four farms were selected, each with eight 2.5-acre ponds. Four ponds were treated with probiotics (W/Pro), while the other four served as control ponds without probiotic addition (W/OPro). On each farm, two ponds were used: one for probiotic addition (W/Pro) and the other as a control (W/OPro). Each pond was stocked with 12,000 fingerlings (5 grams each) per acre. The commercial probiotic (Aqua Star®) was added to the experimental ponds at a rate of 200 grams per acre every two weeks for 180 days. At the end of the evaluation, total ammonia nitrogen (TAN), unionized ammonia (NH3), and nitrite (NO2) levels were significantly (P< 0.05) reduced in the W/Pro ponds compared to the W/OPro ponds. However, total dissolved solids (TDS), pH, and dissolved oxygen (DO) showed no significant differences (P< 0.05) between the two groups. Growth parameters such as final weight, weight gain, daily weight gain, specific growth rate (SGR), total length, standard length, and condition factor were significantly (P< 0.05) improved in the W/Pro ponds. Pond productivity per acre and survival rates were also significantly (P< 0.05) higher in the W/Pro ponds compared to the W/OPro ponds. However, there were no significant differences (P< 0.05) in feed conversion ratio (FCR), protein efficiency ratio (PER), or feed efficiency between the two groups. In conclusion, this study demonstrated that the use of probiotics in semi-intensive aquaculture systems for the Nile tilapia offers significant benefits, including improved water quality, growth performance, body measurements, pond productivity, and survival rates. [ABSTRACT FROM AUTHOR]

Egypt, one of the world's biggest producers of cultured tilapia, is facing significant challenges in using drainage water for aquaculture due to the lack in freshwater. The current study was conducted to evaluate the effects of drainage water treatment on the growth and flesh quality of the Nile tilapia (Oreochromis niloticus), raised on five distinct fish farms in the El-Fayoum Governorate and irrigated with various drainage water sources. Fish growth characteristics, flesh quality, irrigation resources, drainage canals, and water quality of the investigated fish farms were all investigated. The Dayer El-Berka fish farm had the highest values of pH, total hardness, total alkalinity, salinity, and total ammonia, demonstrating the negative effects of the untreated drainage water on aquaculture water quality. All farms, with the exception of Dayer El-Berka and El-Bats fish farm (earthen pond), which showed a high lead content, had copper concentrations below detection limits. Wadi Al-Raian fish farm was recorded with higher cadmium concentrations. The El-Bats fish farm (concrete pond), which is watered with El-Bats drain's treated drainage water, showed the lowest levels of heavy metals. The maximum growth performance was found in the Nile tilapia raised on Wadi Al-Raian and Al-Wadi fish farms, whereas the lowest growth performance was found in Dayer El-Berka fish farms, according to productivity metrics. The current study's findings indicate that fish raised on farms that use treated drainage water for irrigation have great growth rates, superior meat quality, and safe flesh for human consumption. [ABSTRACT FROM AUTHOR]