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The hardness of freshwaters varies depending on geographical locations and calcium is the most important element determining water hardness. Thus, the present study focused on responses of oxidative stress biomarkers in the liver and ATPase activities in the gill of freshwater fish (Oreochromis niloticus) after acute and chronic cadmium exposures in differing calcium levels (30, 60 and 120 mg Ca/L). Fish were exposed to Cd for acute (25 µM, 3 days) and chronic (5 µM, 30 days) durations. There were significant (p < 0.05) alterations in the oxidative stress parameters after cadmium exposures. In the liver, activities of catalase and superoxide dismutase increased in both durations, though activities of glutathione peroxidase, glutathione reductase and glutathione S-transferase decreased. Likewise, levels of glutathione and malondialdehyde increased significantly in both durations. In the gill, there were significant decreases in Na,K-ATPase activity and increases in Mg-ATPase activity. However, calcium alone did not cause any alteration (p > 0.05) in the responses of biomarkers. Data also showed that alterations in biomarkers were highest at the lowest calcium levels. Present data emphasised that calcium protected the fish against the toxic effects of cadmium and suggested that metal toxicity varies depending on the chemical quality of waters from different geographical areas. [ABSTRACT FROM AUTHOR]

The presence of conspecifics plays a crucial role in mitigating stress responses in social teleost species and holds potential for enhancing welfare in captive fish. While studies on social buffering effects have typically focussed on single species, marked interspecific differences can exist. Here, we conducted an analysis of social buffering of stress response in two of the most extensively farmed fish, the Nile tilapia and the koi carp. Subjects were exposed to a behavioural stress response assay (open‐field test) in three conditions simulating increasing levels of social enrichment: isolation, pairs, or shoals of five fish. We obtained five stress indicators from the assay: thigmotaxis, freezing, activity, erratic movements and interindividual distance in conditions with more than one fish. In both species, erratic movements significantly decreased with increasing levels of social enrichment, suggesting a similar social buffering effect. However, other indicators revealed species differences. Koi carp, but not Nile tilapia, showed a socially‐mediated reduction in thigmotaxis, whereas Nile tilapia, but not Koi carp, showed a socially‐mediated reduction in freezing behaviour. Furthermore, social enrichment determined opposite effects on the activity of the two species: Nile tilapia were more active as group size increased, whereas the opposite trend was found in koi carp. Finally, Nile tilapia showed increased interindividual distance with increasing social group size, whereas no changes were observed for koi carp. Our study indicates that the buffering effects of social enrichment on the behavioural stress response do not completely overlap between different fish species, highlighting the importance of developing finely‐tuned species‐specific enrichments and welfare indicators. [ABSTRACT FROM AUTHOR]

Aquatic pollution has been shown to induce different changes ranging from biochemical alterations in single cells to changes in whole populations. In this study, qualitative analyses of liver, brain and gills histopathological parameters were evaluated in Oreochromis niloticus after exposure to water-soluble fractions of crude oil. After preliminary short-term (96 hours) bioassay, fish were subjected to four sublethal concentrations (30, 45, 60, and 75 % of the LC50 corresponding to 28, 41, 55, and 69 mg/l respectively), and a control group using a semi-static renewal method for 90 days. After the exposure period, the liver, brain and gills were harvested, labeled and prepared for photomicrography using standard procedure. Results showed atrophy and necrosis of hepatocytes and degeneration of hepatopancreas in the liver. The histopathological alterations in the brain included mild congestion of cerebral blood vessels, widespread vacuolation of neuropil, necrosis and atrophy of neurons. In the gills, congestion of capillaries, atrophied and necrotic lamellae were detected. Overall, the study revealed that histopathological biomarkers can be relied upon as a suitable tool for accessing long-term impacts of crude oil spillage in the aquatic environment. Therefore, an immediate multi-agency response approach for efficient and effective management of oil spills is recommended. [ABSTRACT FROM AUTHOR]

Seawater (SW)-acclimated Nile tilapia, Oreochromis niloticus, reared under a salinity 30 environment had lower growth and survival than the freshwater (FW)-acclimated fish. It was hypothesized that cells of the SWacclimated fish had not been able to synthesize an adequate level of a compatible osmolyte, myo-inositol (MI), in adjusting to the salinity 30 environment. In this study, MI supplements, at 250, 500, and 750 mg/kg pellets, were provided to the fish through top-dressing. After the 30-day feeding trial, the following parameters were determined: final body weights; survival; biomass increase; feed conversion ratio (FCR); plasma osmolality and ions; and two transcripts in the gills mips250 and mipa1 encoding enzymes responsible for MI biosynthesis. The SW-acclimated O. niloticus receiving 500-mg MI supplement had significantly higher survival, biomass increase, and lower FCR than those of the SW-acclimated fish receiving no supplement. At 500-mg MI supplemental level, the increasing values of plasma osmolality and Na+ observed in SW-acclimated fish were significantly attenuated. The transcript mipa1, but not mips250, was markedly up-regulated in the SW-acclimated O. niloticus, compared with that of the FW-acclimated fish. Again, MI at 500-mg supplement attenuated the upregulation significantly. This study suggests that MI supplement at the optimum level enhanced the performance of SW-acclimated O. niloticus, and through yet unknown mechanisms, attenuated some of their physiological responses to the osmotic stress. [ABSTRACT FROM AUTHOR]

Nocardiosis, caused by Nocardia seriolae, has been a prominent disease in Southeast Asian aquaculture in the last three decades. This granulomatous disease reported in various fish species is responsible for significant economic losses. This study investigated the pathogenicity of N. seriolae in three cultured species in Taiwan: Nile tilapia (omnivore), milkfish (herbivore) and Asian seabass (carnivore). Administration of an infective dose of 1 × 106 CFU/ fish in tilapia, seabass and milkfish demonstrated mortalities of 100%, 90% and 75%, respectively. Additionally, clinical signs namely, granuloma and lesions displayed varying intensities between the groups and pathological scores. Polymerase chain reaction (PCR) amplification specific for N. seriolae was confirmed to be positive (432 bp) using NS1/NG1 primers. Post‐mortem lesions revealed the absence of granulomas in tilapia and milkfish and their presence in the seabass. Interestingly, the gut in tilapia showed an influx of eosinophils suggesting its role during the acute stages of infection. However, post‐challenge, surviving milkfish exhibited granulomatous formations, while surviving seabass progressed toward healing and tissue repair within sampled tissues. Overall, in conclusion, these results demonstrate the versatility in the immunological ability of individual Perciformes to contain this pathogen as a crucial factor that influences its degree of susceptibility. [ABSTRACT FROM AUTHOR]

Background: Trace elements play a crucial role in fish nutrition, with zinc (Zn) being one of the most important elements. BIO-sourced zinc nanoparticles were synthesized using the green microalga Pediastrum boryanum (BIO-ZnNPs, 29.35 nm). 30 or 60 mg/ kg dry feed of the BIO-ZnNPs (BIO-ZnNPs30 and BIO-ZnNPs60) were mixed with the Nile tilapia (Oreochromis niloticus) basal diet and fed to the fish for 8 weeks to evaluate their impact on fish growth, digestion, intestinal integrity, antioxidative status, and immunity. Results: A significant enhancement was observed in all investigated parameters, except for the serum protein profile. BIO-ZnNPs at 60 mg/kg feed elevated the activities of reduced glutathione (GSH) and catalase (CAT), enzymatic antioxidants, but did not induce oxidative stress as reflected by no change in MDA level. Fish intestinal immunity was improved in a dose-dependent manner, in terms of improved morphometry and a higher count of acid mucin-producing goblet cells. Interleukin-8 (IL-8) was upregulated in BIO-ZnNPs30 compared to BIO-ZnNPs60 and control fish groups, while no significant expressions were noted in tumor necrosis factor-alpha (TNFα), nuclear factor kappa B (NFkB), and Caspase3 genes. Conclusion: Overall, BIO-ZnNPs inclusion at 60 mg/kg feed showed the most advantage in different scenarios, compared to BIO-ZnNPs at 30 mg/kg feed. The positive effects on growth and intestinal health suggest that BIO-ZnNPs supplementation of aquafeeds has many benefits for farmed fish. [ABSTRACT FROM AUTHOR]

This study evaluates the impact of dietary supplementation of the blue-green alga Arthrospira platensis NIOF17/003 nanoparticles (AN) on the growth performance, whole-body biochemical compositions, blood biochemistry, steroid hormonal, and fry production efficiency of Nile tilapia (Oreochromis niloticus) broodstock, during the spawning season. After a 21-day preparation period to equip the females and ensure that their ovaries were filled with eggs, mating between the mature females and males took place in a 3:1 ratio during a 14-day spawning cycle. A total of 384 tilapia broodstock 288 females and 96 males with an initial body weight of 450.53±0.75, were divided into four groups; AN0: a basal diet as a control group with no supplementation of Arthrospira platensis, and the other three groups (AN2, AN4, and AN6) were diets supplemented with nanoparticles of A. platensis at levels of 2, 4, and 6 g kg─1 diet, respectively. The results found that fish-fed group AN6 showed the highest significant differences in weight gain (WG), final weight (FW), feed conversion ratio (FCR), protein efficiency ratio (PER), and feed efficiency ratio (FER). Females fed the AN6 diet showed the highest significant fat content. Compared to the AN0 group, fish fed on the supplemented diets showed significant improvement (p < 0.05) in triglyceride, glucose, and aspartate aminotransferase (AST). A gradual increase in AN inclusion level resulted in a gradual increase in the concentrations of luteinizing hormone (LH), and follicle-stimulating hormone (FSH), testosterone, progesterone, and prolactin. The rates (%) of increase in fry production for females fed supplemented diets were 10.5, 18.6, and 32.2% for AN2, AN4, and AN6, respectively, compared to the control group. This work concluded that the inclusion levels of 6 g kg─1 of A. platensis nanoparticles in the diet of Nile tilapia broodstock significantly improved the growth performances, steroid hormone concentrations, and increased the fry production efficiency by 32.2%, respectively. These findings revealed that A. platensis nanoparticles resulted in a significantly enhanced female' reproductive productivity of Nile tilapia broodstock. [ABSTRACT FROM AUTHOR]

The joint impact of tadalafil (Cilais) as a pharmaceutical residue and microplastics on fish is not well comprehended. The current study examined haematological, biochemical, and antioxidant parameters, along with immunohistochemical and histological indications in tilapia (Oreochromis niloticus) after being exposed to tadalafil, polyethylene microplastics (PE-MPs), and their mixtures for 15 days. The fish were distributed into 1st group control group (The fish was maintained in untreated water without any supplements); 2nd group exposed to 10 mg/L PE-MPs;3rd group exposed to 20 mg/l tadalafil (Cilais); 4th group exposed to 20 mg/l tadalafil (Cilais) + 10 mg/LPE-MPs (in triplicate). The levels of creatinine, uric acid, glucose, AST, ALT, and albumin in fish treated with tadalafil alone or in combination with PE-MPs were significantly higher than those in the control group. Fish exposed to PE-MPs, tadalafil, and tadalafil plus PE-MPs showed significantly lower levels of RBCs, Hb, Ht, neutrophils, and lymphocytes compared to the control group. Serum levels of total antioxidant capacity and reduced glutathione (GSH) were notably lowered in fish groups subjected to PE-MPs, tadalafil, and tadalafil + PE-MPs combinations in comparison to the control group. Malondialdehyde (MDA) serum levels were notably elevated in fish groups subjected to PE-MPs, tadalafil, and tadalafil + PE-MPs combinations compared to the control group. The most severe impact was observed in the tadalafil + PE-MPs combination group. Interleukin-6 (IL-6) levels were significantly increased in liver tissues following exposure to both tadalafil and microplastics compared to tissues exposed to only one substance or the control group. Changes in the gills, liver, and renal tissues were seen following exposure to PE-MPs, tadalafil, and tadalafil + PE-MPs combination in comparison to the control group of fish. Ultimately, the mixture of tadalafil and PE-MPs resulted in the most detrimental outcomes. Tadalafil and PE-MPs exhibited showed greater adverse effects, likely due to tadalafil being absorbed onto PE-MPs. [ABSTRACT FROM AUTHOR]

Background: In recent years, anthropogenic activities have released heavy metals and polluted the aquatic environment. This study investigated the ability of the silica-stabilized magnetite (Si-M) nanocomposite materials to dispose of lead nitrate (Pb(NO3)2) toxicity in Nile tilapia and African catfish. Results: Preliminary toxicity tests were conducted and determined the median lethal concentration (LC50) of lead nitrate (Pb(NO3)2) to Nile tilapia and African catfish to be 5 mg/l. The sublethal concentration, equivalent to 1/20 of the 96-hour LC50 Pb(NO3)2, was selected for our experiment. Fish of each species were divided into four duplicated groups. The first group served as the control negative group, while the second group (Pb group) was exposed to 0.25 mg/l Pb(NO3)2 (1/20 of the 96-hour LC50). The third group (Si-MNPs) was exposed to silica-stabilized magnetite nanoparticles at a concentration of 1 mg/l, and the fourth group (Pb + Si-MNPs) was exposed simultaneously to Pb(NO3)2 and Si-MNPs at the same concentrations as the second and third groups. Throughout the experimental period, no mortalities or abnormal clinical observations were recorded in any of the treated groups, except for melanosis and abnormal nervous behavior observed in some fish in the Pb group. After three weeks of sublethal exposure, we analyzed hepatorenal indices, oxidative stress parameters, and genotoxicity. Values of alkaline phosphatase (ALP), gamma-glutamyl transferase (GGT), urea, and creatinine were significantly higher in the Pb-intoxicated groups compared to the control and Pb + Si-MNPs groups in both fish species. Oxidative stress parameters showed a significant decrease in reduced glutathione (GSH) concentration, along with a significant increase in malondialdehyde (MDA) and protein carbonyl content (PCC) concentrations, as well as DNA fragmentation percentage in the Pb group. However, these values were nearly restored to control levels in the Pb + Si-MNPs groups. High lead accumulation was observed in the liver and gills of the Pb group, with the least accumulation in the muscles of tilapia and catfish in the Pb + Si-MNPs group. Histopathological analysis of tissue samples from Pb-exposed groups of tilapia and catfish revealed brain vacuolation, gill fusion, hyperplasia, and marked hepatocellular and renal necrosis, contrasting with Pb + Si-MNP group, which appeared to have an apparently normal tissue structure. Conclusions: Our results demonstrate that Si-MNPs are safe and effective aqueous additives in reducing the toxic effects of Pb (NO3)2 on fish tissue through the lead-chelating ability of Si-MNPs in water before being absorbed by fish. [ABSTRACT FROM AUTHOR]

Nile tilapia (Oreochromis niloticus) is valued in aquaculture because of its quick development and ability to thrive in various environments. Myxosporeans are among the fish parasites that affect fish productivity, as they impact fish growth and reproduction, resulting in large fish deaths in farms and hatcheries. This study has been focused on morpho-molecular identification for the myxosporean parasites infecting Nile tilapia from three governorates in Egypt and assessment of gene expression of different cytokines (Interleukin-1βeta (IL-1β), major histocompatibility complex class II (MHC-II), and clusters of differentiation 4 (CD-4) and 8 (CD-8)) in tissues. Additionally, this work aimed to correlate the developed histopathological alterations and inflammatory reactions in gills with immunohistochemical expression of inducible nitric oxide synthase (iNOS) and tumor necrosis factor-alpha (TNF-α). Finally, the infected fish's cortisol levels and blood glucose were assessed. Results of BLAST sequence analysis of the 18S rRNA for the collected protozoans confirmed Myxobolus agolus, M. brachysporus, M. tilapiae, and Henneguya species. The molecular characterization of the immunological status of gills revealed marked upregulation of different inflammatory cytokines in the gills of infected fish. There was a significantly increased serum cortisol and glucose level in infected fish compared with control, non-infected ones. Severe histopathological alterations were observed in the infected fish gills, associated with increased expression of iNOS and TNF-α and related to myxosporean infection. The present study provides new insights into oxidative stress biomarkers in Nile tilapia infected with Myxosporeans and elucidates the gill's immune status changes as a portal of entry for protozoa that contribute to tissue damage. [ABSTRACT FROM AUTHOR]

Yeasts are unicellular eukaryotic microorganisms extensively employed in various applications, notably as an alternative source of protein in feeds, owing to their nutritional benefits. Despite their potential, marine and mangrove yeast species used in the aquaculture industry have received little attention in the Philippines. Pichia kudriavzevii (A2B R1 ISO 3), sourced from bark samples, was selected and mass-produced due to its high protein content and amino acid profile. The dried biomass of P. kudriavzevii was incorporated into the diets of Nile tilapia (Oreochromis niloticus) juveniles at varying inclusion levels (0, 1, 2, and 4 g/kg diet) and its effect on their growth performance, body composition, and liver and intestinal morphology was assessed after 40 days of feeding. The groups that received P. kudriavzevii at a concentration of 2 g/kg diet exhibited higher final body weight, percent weight gain, and specific growth rate in comparison to the other treatment groups. Whole body proximate composition did not vary among the dietary groups. Intestinal and liver histopathology also indicated no abnormalities. These findings suggest the potential of ascomycetous P. kudriavzevii as a beneficial feed additive in Nile tilapia diets, warranting further investigation into its long-term effects and broader applications in fish culture. [ABSTRACT FROM AUTHOR]

The present study aims to evaluate the potential effects of cyanobacteria on water quality parameters and Oreochromis niloticus in the fish ponds at Al-Abbassa Fish Hatchery, Sharkia Governorate, Egypt. The study identified five cyanobacterial genera: namely, Anabaena, Gleotrichia, Lyngbya, Oscillatoria and Phormidium. Oscillatoria sp. was the dominant genus in the selected fish ponds. Physico-chemical parameters of water samples showed significant variations during the four seasons. Anabaena sp. extract had the most toxic effect on the survival rate of O. niloticus after 72 h of exposure. Biochemical parameters of collected O. niloticus fish significantly increased compared to the control group. We concluded that the detected cyanobacterial genera in the fish ponds affected water quality and O. niloticus fish. [ABSTRACT FROM AUTHOR]

This study aimed to evaluate the effects of salinity on the proximate composition and fatty acid profile of the Nile tilapia fillet when reared in a biofloc system. Juveniles (200 ± 10 g) were reared at salinities of 2, 8, 15 and 22 PSU for 56 days. At the end of the experiment, the proximate composition and the fatty acid profile were evaluated in the fillets. No significant differences were observed for crude protein, ether extract, dry matter and ash levels. However, saturated (SFA) and monounsaturated (MUFA) fatty acids were higher in tilapia reared at 2 PSU compared to other salinities (8, 15, and 22 PSU). The polyunsaturated fatty acids (PUFA) contents did not vary among fish reared at salinities of 2, 8, and 15 PSU but were significantly lowest in tilapia reared at 22 PSU. The overall results suggest that the different salinities do not significantly affect the proximate composition of the Nile tilapia file reared in a biofloc system. On the other hand, the fatty acid composition was influenced by salinity, as a reduction in PUFA content was observed at the highest tested salinity (22 PSU) and an increase in SFA and MUFA contents were recorded at the lowest tested salinity (2 PSU). [ABSTRACT FROM AUTHOR]

Survival analysis has proven to be a robust tool for studies in humans, and recently, it has been adopted in studies with animals, but very little in fish. The production of uniform fingerlings has been one challenge of aquaculture, influenced by the use of the efficient breeders. We aimed to present, for the first time in aquaculture, a survival analysis as a tool for decision-making by using the relationship between the main morphometric traits and the spawning time of Nile tilapia females up to 28 days after mating in an intensive system. We used 78 females and 26 males from which ten traits were evaluated. A check was made for the presence of eggs in the female mouth (spawning) every seven days until the final twenty-eight days. Confirmation of eggs was defined as uncensored data (C = 1) and absence of eggs as censored (C = 0). The Cox proportional hazards ratio and Kaplan–Meier models were adjusted to analyze the data. Females with a standard length of 19.19 cm (small group) and males with a weight of 259.14 g (small group) reproduced early, being more adapted to 1000 L tanks in a recirculation system. Less heavy egg masses were also related to early spawning. Therefore, the traits, standard length of the female, egg mass weight, and male weight, affected the presence of eggs up to 28 days and should be used as selection criteria for early breeders. Besides, the survival analysis was accurate as a tool for tilapia breeding management in an intensive system. [ABSTRACT FROM AUTHOR]

The bioactive compounds of Artemisia annua have been used as feed supplements due to their pharmacological activities. The present study examined the effect of short-term feeding with a supplemented diet on the growth, feed efficiency, intestinal morphology, stress, immune system, and antioxidant biomarkers of juvenile Nile tilapia (Oreochromis niloticus) to evaluate the efficacy of using an alcoholic extract of A. annua (ae-Aa) as an additive in fish feed. Juvenile fish (200 fish, 30.43 ± 0.54 g) were distributed in 10 tanks (400 L, 20 fish/tank) corresponding to two treatments, each with five replicates. The fish were fed either a control diet (37% protein, 11% lipid: ae-Aa free) or an equivalent diet containing 0.5% ae-Aa to satiation for 15 days. Subsequently, blood, liver, and intestine samples were obtained from 10 fish per treatment group (2 fish per tank). Dietary supplementation with ae-Aa affected the leukocyte count (27.9 vs. 19.7 × 103 µL−1, ae-Aa group vs. control group), leukocyte respiratory activity (0.3 vs. 0.2 DO), and serum lysozyme concentration (28.1 vs. 22.4 ng dL−1) but not blood cells or the oxygen-carrying capacity. Treatment with ae-Aa reduced the plasma cortisol level (11.0 vs. 15.1 µL−1) but did not affect the levels of either glucose or chloride. Dietary ae-Aa influenced hepatic catalase (453.2 vs. 255.7 µmol H2O2 mg pt−1 min−1), glutathione-S-transferase (406.9 vs. 279.8 nmol mg pt−1 min−1), glutathione (4.5 vs. 2.9 nmol mg pt−1), and superoxide dismutase activity (22.4 vs. 20.1 U mg pt−1) and thus affected the antioxidant capacity, as reflected by reductions in lipid peroxidation (21.3 vs. 34.4 nmol mg pt−1) and DNA damage (26.7 vs. 32.2 µg DNA mg pt−1). Dietary ae-Aa increased the intestinal villus area and improved growth (body mass, 24.2 vs. 20.7 g; body length, 2.0 vs. 1.6 cm). Based on the above-described results, the administration of dietary ae-Aa, even for a short period, may have beneficial effects on immunity and oxidant defences and enhance the growth rate. [ABSTRACT FROM AUTHOR]

Plastic pollution is one of today's most serious global issues in the aquatic environment and organisms, including entanglements, ingestion, and possible toxicity. The study was carried out to screen and identify the microplastics in some tissues of fish species from Sallari and Hauren Shanu burrow pits in Kano metropolis. A total of 60 fish samples comprising two species; Oreochromis niloticus (n = 30) and Tilapia zilli (n = 30), were collected from sampling sites (Sallari and Hauren Shanu). The fishes' gastrointestinal tract, gills and muscle tissues were collected, screenedand examined using a dissecting microscope for the presence of microplastics. Microplastics were found in all the examined fish tissue samples from both sites. In the samples from Hauren Shanu, 63% of the fish had microplastics in the gastrointestinal tract, 46% in muscle and 36% in the gills. In samples from Sallari, 33% of the fish had microplastics in theirgastrointestinal tract, 16% in muscle and 23% in the gills. Microplastics which include fibers, fragments, microbeads and tyre-dusts were observed in all the examined tissues of Oreochromis niloticus and Tilapia zilli although not significantly different (p > 0.05) between the fish species. The study demonstrates microplastics presence in the fish species and portrays to a large extent some degree of plastic contamination in Hauren shanu and Sallari burrow pits. Further assessments should be done on human food contamination by microplastics and their effects on human health. [ABSTRACT FROM AUTHOR]

Nile tilapia Oreochromis niloticus is one of the most important fishery resources and a valuable fish species for aquaculture programmes. It is found in almost all waters and is widely dispersed. Several natural populations of this species have been impacted by genetic pollution despite their significant economic relevance. Understanding population structure is a crucial first step in protecting this species in its native habitats as well as in choosing which wild stocks to use in hatchery initiatives. To demonstrate the genetic-population structure of this species, genetic differences among three geographically secluded populations of O. niloticus were investigated utilizing mitochondrial DNA cytochrome b gene sequences. The results were used to estimate the levels of genetic variability within and among the populations. The 56 cyt b (821 bp) sequences analysis revealed 21 haplotypes, with a nucleotide diversity of 0.0510 and a haplotype diversity of 0.881. In each of the populations, seven (7) singleton variable sites and 19 informative-parsimony sites, genetic diversity could be identified and few population haplotypes were found, indicating a minor genetic distinction between them. For the purpose of conservation and/or Nile tilapia breeding programmes, this information would assist in choosing the fish populations that maintain greater genetic variation in O. niloticus. [ABSTRACT FROM AUTHOR]

This study investigated the effects of dietary supplementation with the product Hilyses on growth performance, feed utilization, nutrient composition, hematological parameters, serum biochemistry, immune function, antioxidant status, and digestive enzyme activity in juvenile Nile tilapia (Oreochromis niloticus, initial body weight 4.24 ± 0.01 g). The fish were fed diets supplemented with Hilyses at concentrations of 0, 1, 2, or 3 g/kg for a period of 8 weeks. The results showed that supplementation with Hilyses at levels up to 2 g/kg diet significantly improved final body weight, weight gain, specific growth rate, feed efficiency ratio, protein efficiency ratio, apparent protein utilization, and energy utilization compared to the control diet without Hilyses. Carcass crude protein content and moisture were significantly higher in Hilyses-fed groups, while crude lipid content decreased at the 3 g/kg supplementation level. Hilyses supplementation enhanced various hematological parameters, including increased red blood cell count, total leukocyte count, hemoglobin concentration, hematocrit, and mean corpuscular volume. Serum biochemistry and immune function markers like total protein, albumin, complement component C3, IgM, and IgG were significantly elevated in the 2 and 3 g/kg Hilyses groups. Antioxidant enzyme activities (catalase, glutathione peroxidase, total superoxide dismutase) were enhanced, and lipid peroxidation was reduced, in the 2 g/kg Hilyses group. Digestive enzyme activities, particularly protease and lipase, were also improved with Hilyses supplementation. Histological examination showed reduced lipid deposition in the liver and increased branching of intestinal villi at the 2 g/kg Hilyses level. Overall, these results indicated that dietary Hilyses supplementation at 2 g/kg diet optimizes growth, feed utilization, nutrient composition, hematology, immunity, antioxidant status, and digestive function in juvenile Nile tilapia. [ABSTRACT FROM AUTHOR]

Background: Moringa oleifera, a well-known medicinal plant, has been used in aquafeed as a dietary supplement. Based on previous studies, insufficient research is available on the dietary supplementation of Nile tilapia with M. oleifera leaf and seed mixtures, specifically the fermented form. Therefore, this study aimed to investigate the efficacy of fermented (FMO) versus non-fermented M. oleifera (MO) leaf and seed mixtures on immunological parameters, antioxidant activity, growth performance, and resistance to A. hydrophila infection after a 30-day feeding trial on Nile tilapia. Methods: A total of 180 fingerlings were randomly divided into four groups in addition to the control group (36 fish each, in triplicate). Fish in the tested groups were fed on basal diet supplemented with MO5%, MO10%, FMO5%, and FMO10%, while those in control were fed on basal diet only. After the feeding trial, fish were challenged with A. hydrophila. The immunomodulatory activity of M. oleifera was evaluated in terms of phagocytic and lysozyme activities, immune-related cytokines and IgM gene expression. Antioxidants, and growth-promoting activities were also assessed. Results: The results revealed that fish supplemented FMO markedly in FMO10% group followed by FMO5%, exhibited significant (P < 0.05) improvement in the tested immunological, hepatic antioxidants, and growth performance parameters. Furthermore, the highest survival rate post-challenge with mild clinical symptoms, and the lowest A. hydrophila bacterial count were reported in these groups. Meanwhile, MO10%-supplementation exhibited the opposite trend. Conclusions: The study' conclusion suggests that fermented M. oleifera leaf and seed mixture is a promising growth-promoting and immunostimulatory feed-additive candidate for Nile tilapia and could reduce the losses caused by A. hydrophila infection. [ABSTRACT FROM AUTHOR]

Aim Methods and Results Conclusions Many fish species can harbour a wide range of pathogenic agents in their tissues. Of many pathogens, the parasitic nematode of genus Contracaecum, which resides in the tissues of fish species, can results in fish‐borne infections in humans. This study was planned to assess consumers' awareness of fish‐borne zoonoses in the fishing sites of Lake Chamo, Arba Minch, Ethiopia. The study was also aimed at demonstrating the zoonotic nematode, Contracaecum parasites in the Oreochromis niloticus and Lates niloticus fishes collected from Lake Chamo, Arba Minch, Ethiopia.Assessment of awareness about fish‐borne zoonoses was conducted in randomly selected participants (n = 162) using face‐to‐face interviews via a structured and semi‐structured questionnaire. Besides, 70 fishes (O. niloticus = 35 and L. niloticus = 35) were examined for the presence of larva of Contracaecum and other anisakid genera through standard dissection, pepsin‐hydrochloric acid digestion and microscopic observation. Consumers have inadequate awareness about fish‐borne zoonoses based on the answers they provided to the questions. The majority of respondents (82%) consume raw fish in the area. Of these, a significantly higher proportion were male (p < 0.001), completed their elementary or high school (p = 0.004), Orthodox Christian (p = 0.044), fishermen (p < 0.001) and participants without previous information about fish‐borne zoonoses (p < 0.001). Overall, of examined fishes (n = 70), n = 15 (21.4%, 95% CI, 12.8–33.2) were infected with Contracaecum larva. A significant (p = 0.028) higher infection prevalence was noted in L. niloticus (34.3%, 95% CI, 19.7–52.3) compared to O. niloticus (8.6%, 95% CI, 2.2–24.2). A unit gram addition in the total weight of fish would significantly raise the risk of Contracaecum infection by 1% (p < 0.001).The presence of Contracaecum, a zoonotic nematode in the fishes, which are often preferred by consumers for raw dishes, designates a high risk of possible fish‐borne infections in the area. Thus, providing education and training for fishermen, visitors of the area, and local people who visit the area for fish consumption, it is inevitably important to minimize the risk. Furthermore, health workers should suspect fish‐borne infections, such as anisakidosis in patients who have a history of raw fish consumption in Arba Minch, Ethiopia. [ABSTRACT FROM AUTHOR]

Context: Recently, prioritize has been given to using natural phytogenic or nano compounds as growth promoters and immunostimulants in fish diets as an alternative to antibiotics. Aims: The main propose of this trial was to determine the impact of supplementing diets with spirulina or curcumin nanoparticles on the performance and health indicators of Nile tilapia fingerlings. Methods: In a 56-day feeding trial, 180 tilapia fingerlings were assigned into three main groups, as follows: 1st, control group, 2nd, Spirulina platensis (SP; 5 g kg-1 diet) and 3rd, curcumin nanoparticles (CUR-NPs; 30 mg kg-1 diet). Key results: Incorporating tilapia diets with SP or CUR-NPs significantly improved performance, body chemical analysis, blood biochemical and hematological indices, digestive enzyme activities, and antioxidant and immunostimulant features compared to the control. Conclusion: Fortified tilapia diets with CUR-NPs or SP efficiently boost the productivity and health of Nile tilapia fingerlings. Implications: The research introduces new practical solutions for applying safe feed additives as alternatives to antibiotics in tilapia farming. [ABSTRACT FROM AUTHOR]

Simple Summary: While various commercial probiotics are supplemented in biofloc technology (BFT), there is limited information regarding their impacts on farmed fish. This study investigated the effects of three commercial probiotics, two alone and one in combination with enzymes, on Nile tilapia reared in BFT. Incorporating multi-species probiotics along with enzymes into a BFT significantly enhanced tilapia weight gain, liver, and intestine weight, improving digestion and absorption responses, highlighting the potential benefits of BFT. Though different types of commercial probiotics are supplemented in biofloc technology (BFT), very little information is available on their effects on the farmed fish. Therefore, this study focused on evaluating the effects of three most commonly used commercial probiotics on the growth performance, intestinal histomorphology, and intestinal microbiota of Nile tilapia (Oreochromis niloticus) reared in BFT. Tilapia fry, with an average weight of 3.02 ± 0.50 g, were stocked at a density of 60 fry/0.2 m3, and cultured for 90 days. Three commercial probiotics were administered, with three replications for each: a single-genus multi-species probiotic (Bacillus spp.) (T1), a multi-genus multi-species probiotic (Bacillus sp., Lactobacillus sp., Nitrosomonas sp., Nitrobacter sp.) (T2), and a multi-species probiotic (Bacillus spp.) combined with enzymes including amylase, protease, cellulase, and xylanase (T3). The results showed significant variations in growth and feed utilization, with T3 outperforming other treatments in terms of weight gain, liver weight, and intestine weight. Adding Bacillus spp. with enzymes (T3) to water significantly increased the histomorphological parameters (villi length, villi depth, crypt depth, muscle thickness, intestinal thickness) as well as microbes (total viable count and total lactic acid bacteria) of intestine of fish compared to T1 and T2, leading to improved digestion and absorption responses. It is concluded that the supplementation of commercial probiotics has potential benefits on farmed fish species in BFT. [ABSTRACT FROM AUTHOR]

The supplementation of aquafeed with probiotics is recommended for feasible aquaculture activities. Therefore, the aim of current study was to investigate the potential effects of probiotics on growth performance, feed utilization, biochemical attributes, redox status and immunity response as well as the transcription of heat‐shock protein 70 (HSP70) and insulin‐like growth factor‐1 (IGF‐1) genes of Nile tilapia (Oreochromis niloticus; n = 120). Fish with an initial weight of 8.17 ± 0.02 g/fish were randomly divided into four treatment groups and were fed diets containing 0, 0.5, 1 and 1.5 mg immunobacteryne (IMB)/kg diet respectively. Dietary IMB at 1.5 g/kg diet significantly improved the growth performance, feed consumption and growth hormone secretion of the experimental fish (p < 0.05). The 1 or 1.5 g IMB/kg diet boosted phagocytic activities and innate immune response. Serum total protein, total cholesterol, triglycerides and glucose were significantly increased in the groups that were fed 1 and 1.5 mg IMB/kg diet compared to the control (p < 0.05). Meanwhile, the levels of uric acid, creatinine, liver enzymes (aspartate transaminase and alanine transaminase) and cortisol hormone were significantly reduced in the aforementioned treated groups compared to the control (p < 0.05). All fish fed IMB‐supplemented diet showed a significant increase in the expression of IGF‐1 gene, while the transcription of HSP70 was significantly decreased (p < 0.05). In conclusion, the dietary inclusion of IMB (1 g/kg diet) enhanced growth promoters, feed efficacy, blood biochemical, redox balance and nonspecific immune responses in Nile tilapia fingerlings. [ABSTRACT FROM AUTHOR]

Simple Summary: Tilapia is the second-most-farmed fish worldwide which plays a critical role in providing high-quality proteins to human. However, infections caused by S. agalactiae result in huge economic losses. Moreover, the spreads of antibiotic resistance restrict the use of antibiotics in treating S. agalactiae infections. Here, we tried to develop anti-S. agalactiae drugs by inhibiting SrtA to overcome infections caused by resistant bacterial strains. Sortase A (SrtA) is responsible for anchoring surface proteins to the cell wall, and has been identified as a promising target developing anti-infective drugs of Gram-positive bacteria. The aim of the study was to identify inhibitors of Streptococcus agalactiae (S. agalactiae) SrtA from natural compounds to overcome the spread of antibiotic resistance in aquaculture. Here, we found that the MIC of fraxetin against S. agalactiae was higher than 256 μg/mL, indicating that fraxetin had no anti- S. agalactiae activity. But fraxetin could dose-dependently decrease the activity of SrtA in vitro at concentrations ranging between 4–32 μg/mL by a fluorescence resonance energy transfer (FRET) assay. Moreover, the inhibition of SrtA by fraxetin decreased the anchoring of surface proteins with the LPXTG motif to the cell wall by detecting the immunofluorescence change of serine-rich repeat protein 1 (Srr1) on the bacterial cell surface. The results of fibronectin binding and cell adhesion assays indicated that fraxetin could significantly decrease the adhesion ability of S. agalactiae in a dose-dependent manner. The results were further proven by immunofluorescence staining. Animal challenge results showed that treatment with fraxetin could reduce the mortality of tilapia infected with S. agalactiae to 46.67%, indicating that fraxetin could provide a significant amount of protection to tilapia by inactivating SrtA. Taken together, these findings provided a novel inhibitor of S. agalactiae SrtA and a promising candidate for treating S. agalactiae infections in aquaculture. [ABSTRACT FROM AUTHOR]

The article aims to diagnose and redesing the teaching-learning prococess in the training module breeding and management of small animals, for the implementation of a management proposal for red tilapia (Oreochromis niloticus). The module that is part of the professional figure in "Agricultural Production" at the Saraguro Educational Unit was chosen. This research has a mixed approach with a descriptive study. Empirical methods were used such as a survey of students, graduates, managers and companies; The research questions were prepared, and through the collection and analysis of the data, answers were given to them, the documentary analysis was carried out, as well as the observation. From the diagnosis carried out, it was found that the teaching-learning process of the aforementioned training module presents coincident strengths and weaknesses in the four surveys, which demonstrates its necessary improvement. [ABSTRACT FROM AUTHOR]

Background: When pesticides are introduced into wetlands by agriculture, fish quickly absorb them through their gills. Pesticides reduce hatchability, impede growth, and antioxidant response, killing fish. Therefore, it's crucial to find effective pesticide mitigation methods for fish. Objective: In this study, the effects of garlic (Allium sativum) oil on the growth, haematology, biochemistry and histopathology parameters of Nile tilapia (Oreochromis niloticus) exposed to cypermethrin toxicity were investigated. Methods: In the research, cypermethrin was added to the water of the experimental groups at a rate of 1:20 of the LC50 value, and 1.00% garlic oil was added to the fish feed. Fish with an initial weight of 30.26 ± 0.26 g were fed for 45 days. Results: At the end of feeding, the final weights were determined as 69.39 ± 0.41 (G1), 61.81 ± 0.65 (G2), 82.25 ± 0.36 (G3), and 75.04 ± 0.68 (G4) grams, respectively. Histopathological examinations revealed serious lesions in the gill, liver, brain, and muscle tissues in the cypermethrin group, whereas these lesions were minimal or absent in the garlic oil group. Conclusions: Garlic oil supplementation had positive effects on growth, haematology, blood biochemistry, hepatosomatic index and histopathological parameters. These findings suggest that garlic oil is a potential protective agent against cypermethrin toxicity. [ABSTRACT FROM AUTHOR]

Ancient roles of CRF and ACTH in immune-endocrine interactions were obtained early in the development process of fish alimentary canal. The immunolocalization of corticotrophin releasing factor (CRF) and adrenocorticotropic hormone (ACTH) was inspected in the developing gut of Oreochromis niloticus larvae. The aim was to investigate a possible involvement of these molecules early in the integration of immunological and endocrine systems. Immediately after hatching, the gut of O. niloticus is observed as a straight undifferentiated tube, and with the rapid development, it differentiates into four segments: buccopharinx, esophagus, presumptive stomach and intestine. The immunohistochemical investigation showed the immunolocalization of CRF in the growing digestive tract at all stages (from hatching to 42 days post-hatching). Immunoreaction of CRF was detected in the mucosal epithelium of both the undifferentiated gut and the developing esophagus, stomach, and intestine. Furthermore, CRF immunoreactivity was found in the gastric glands of the stomach. The number of CRF-immunoreactive (ir) cells and the strength of immunoreaction gradually increased as the larvae developed, particularly after the exogenous feeding began; 21 days after hatching. Only the goblet cells of the developing intestine exhibited an ACTH immunoreactivity, which increased at 7dph during the yolk sac resorbtion period. A dramatic decrease was recoded in the number and size of ACTH-ir cells associated with the beginning of the exogenous feeding, and at 28 days post hatching, a very weak immunoreaction was produced. The widespread anatomic distribution and early onset of CRF and ACTH activities, in the developing gut, indicate that these molecules play a functional role in food intake, growth, immunological response, and osmoregulation during O. niloticus development, particularly with the start of the exogenous feeding. [ABSTRACT FROM AUTHOR]

One of the key challenges in aquaculture is the selection of individuals with superior traits, including rapid growth rate, high flesh quality, and disease resistance. Marker-assisted selection (MAS) using molecular markers (e.g., simple sequence repeats; SSR) is known to be more effective in identifying individuals with specific traits based on their genetic makeup. The current study aimed to examine SSR markers across different linkage groups in their efficiency in characterizing the Nile tilapia fish with superior growth performance traits for usage as effective tools for MAS. A total of 152 Nile tilapia samples with identical ages but contrasting growth performances were collected from a fish farm in Kafr El-Sheik Governorate, Egypt. The collected genotypes were evaluated for growth performance metrics such as weight and length, and their microsatellite allelic patterns were also analyzed. A total of 13 microsatellite markers were assessed in the two sampled Nile tilapia categories. The t-test of growth performance traits between the two fish categories revealed highly significant differences in body weight and length. The average number of alleles per locus in the large and small populations was 2.6 and 2.2, respectively. The analyzed populations showed a significant deviation from Hardy-Weinberg equilibrium.Only seven markers showed private alleles unique to either small or large populations, indicating the suitability of these markers for association genetic studies. The studied markers showed low to moderate gene diversity (H), which ranged between 0.25 and 0.48, with an average of 0.41. The discrimination power of the studied loci was relatively high (D = 0.888). The discrepancies in growth parameters between the investigated populations were aligned with the disparities in allele frequency, indicating a possible correlation between certain allele(s) and growth performance characteristics. The present study highlighted the effectiveness of specific SSRs in addressing growth parameters during the planning for the Nile tilapia selection in breeding programs. [ABSTRACT FROM AUTHOR]

The prospective effect of beetroot extract (Beta vulgaris L.) to resist the toxic effect of lead (Pb) and enhance the immune status and antioxidant enzyme of the Nile tilapia (Oreochromis niloticus) was studied. Fish specimens were divided into 4 groups: C (control group), Pb (group subjected to lead), T1, and T2 (groups injected intraperitoneal with 100 and 150mg/ kg of beetroot extract 2 weeks before being subjected to Pb, respectively). The effects were addressed on the humoral immune parameters, (antiproteases, lysozyme total protein, and globulin) and antioxidant enzymes [Glutathione S-transferase (GST), superoxide dismutase (SOD), catalase (CAT), and peroxidase (POX) activities], as well as some biochemical parameters. Pb accumulation was studied in gills, liver, and muscle tissues. The results revealed a significant enhancement in some immune parameters viz. a lysozyme and total protein in T1 groups compared to other groups, especially with the Pb group which showed the lowest significant values (P< 0.05). The groups injected with beetroot extract showed the lowest significant values (P< 0.05) of Pb accumulation in tissues compared to Pb group. While, T1 group recorded a significant increase (P< 0.05) in hepatic protein content, GST, SOD, CAT, and POX, respectively, compared to the Pb group. Moreover, Pb group showed a significant decrease compared to the control group. Most of the biochemical parameters, including glucose, cholesterol, AST, and uric acid recorded the highest values in Pb group compared to the other groups, but without significant difference. The albumin value of T1 group showed the highest significant values compared to other groups. To conclude, the injection of the Nile tilapia with 100mg/ kg of beetroot extract may contribute to protecting fish from the harmful effects of lead by enhancing the immune system and antioxidant enzymes, and improving the general fish health. [ABSTRACT FROM AUTHOR]

The study aimed to evaluate the impact of different carbon sources on biofloc generation of Nile tilapia, Oreochromis niloticus and common carp, Cyprinus carpio. 360 healthfully Nile tilapia and common carp were subject to an experiment for the current research work. The Nile tilapia had a starting body weight of 6.5±0.4g, while the common carp had a starting body weight of 6.9±0.1g. The samples were divided into six equal groups, with the initial three groups designated for the Nile tilapia and the remaining groups for the common carp. Each group was duplicated three times with 20 fish in each replication. Four diets were adjusted for the experiment. The first and fourth groups, serving as control groups, were given a baseline control diet containing 25% crude protein (CP). Groups two, three, five, and six were given a basic diet with 25% CP, along with additional molas and starch for carbohydrate supplies.The trial extended for 60 days. Both the Nile tilapia and common carp exhibited the highest feed conversion ratio and a superior weight gain when provided with starch and molasses compared to the control group. There was no notable change in water temperature across the groups. The biofloc groups had higher oxygen levels compared to the control group. Ammonia levels decreased in all treated groups in comparison with the control groups. The Nile tilapia and the common carp experienced an improvement in both growth performance and water quality in a biofloc system utilizing different carbon sources. [ABSTRACT FROM AUTHOR]

This study assessed the marketing efficiency of two crucial fish species in Egypt, the Nile tilapia (Balti) and mullet (Bouri), contributing 73.4% to the nation's total fish production. Utilizing data envelopment analysis (DEA) and the variable returns to scale model, marketing efficiency for the Nile tilapia ranged from approximately 62.4 to 100%, with an average of 87.5%, while mullet fish exhibited a range of 36.2 to 100%, averaging 83.4%. The findings suggest a marketing efficiency deficit of 12.5% for the Nile tilapia and 16.6% for mullet fish, attributable to factors not considered in the model. To enhance efficiency, increasing marketing margins or fish production is recommended. Scale efficiency analysis revealed that some fishers failed to achieve an optimal production efficiency. The Nile tilapia could increase productivity by 24.1%, through optimization at the minimum point on the average total cost curve (MC = AC). Similarly, mullet fish could increase productivity by 27.4%, using the same approach. Furthermore, 70% of the Nile tilapia volume demonstrated increasing returns to scale (IRS), while 25% exhibited decreasing returns to scale (DRS). For mullet, 80% demonstrated IRS, and 10% exhibited DRS. Identified marketing challenges included high summer temperatures causing significant losses, financial constraints, insufficient liquidity, high labor costs, lack of marketing information, and elevated taxes. Recommendations include providing comprehensive marketing information, ensuring well-equipped transportation, attempting to enhance liquidity through lending, and supporting energy to reduce costs for fishing-related activities. [ABSTRACT FROM AUTHOR]

This study investigated the parasitic infestations among 300 tilapia fish (Oreochromis niloticus and O. aureus) and the water parameters of sixty water samples from Damietta Governorate. Clinically, affected fish displayed emaciation and opacity in the eye with focal external hemorrhages. The detected parasites were protozoa (Chilodonella hexasticha), monogenea (Cichlidogyrus tilapiae), and digenetic trematode metacercaria (Heterphyes spp, Haplorichis spp, Clinostomum tilapiae, Euclinostomum heterostomum, Diplostomum spathacaum, Centrocestus formosanus, and other unidentified metacercaria). The total infestation rate was 60%, (66.7% in O. niloticus, followed by 53.3% in O. aureus). Summer was the season with the highest infestation (80% in O. niloticus and 64% in O. aureus). Water parameters such as visibility, oxygen levels, pH, and total alkalinity exhibited a significantly negative correlation with parasitic infestation. Conversely, water temperature, unionized ammonia, and NO3-N concentrations displayed a positive correlation. The occurrence of parasitic infestation increased in highly polluted water, where zinc exhibited a notable positive correlation with its infestation. Histopathological examinations of tilapia species exhibited various pathological alterations. C. hexasticha embedded within the secondary lamellae of the gills that were surrounded by a connective tissue capsule. Additionally, C. tilapiae was identified within the musculature, situated between muscle bundles. Parasitic cysts of Haplorchis spp. were encapsulated with connective tissue that caused pressure atrophy in adjacent hepatocytes. Furthermore, E. heterostomum, was identified in renal tissue. Thus, this study affirmed the connection between parasitic prevalence and changes in the aquatic environment. Understanding these dynamics is essential for managing and mitigating the impact of climate change on the epidemiological maps for parasitic diseases in fish populations, ultimately contributing to disease minimization and the promotion of sustainability in aquaculture. [ABSTRACT FROM AUTHOR]

Reproduction is among the most vital biological processes in the life cycle of any organism, such as fish. The biology of Oreochromis niloticus reproduction in Lake Nasser and Lake Nubia was studied using different mesh sizes of gill nets. A total of 480 Oreochromis niloticus were caught from Lake Nasser, Egypt, and 369 from Lake Nubia, Sudan, from January through December 2021. Sex ratio size at first maturity and maturity stages of O. niloticus were examined. In Nasser's Lake, the sex ratio of male to female was 1:1.02, whereas in Lake Nubia, it was 1:0.89. The first maturity length in Lake Nasser was 27.5cm for males and 27cm for females, while in Lake Nubia, it was 32cm for males and 26cm for females. The gonado somatic index indicated that the species breeds in Lake Nasser and Nubia during summer and spring, respectively. [ABSTRACT FROM AUTHOR]

The present study investigates molecular‐based PCR techniques to estimate the prevalence of fish pathogens in southwest Mexico where recurrent mortality in the tilapia cultures has been observed. Sample of internal organs and lesions of Nile tilapia were taken and analysed in 2018, 2019, 2020 and 2022 to detect bacterial pathogens using PCR. No samples were taken in 2021 due to the COVID‐19 pandemic. The real‐time PCR conditions were optimized to allow a qualitative reliable detection of the bacteria from fixed fish tissue. A total of 599 pond‐ and cage‐cultured tilapia from the southwestern Mexican Pacific (Guerrero, Oaxaca and Chiapas states) were analysed. In this tropical region, during 2018 and 2019 water temperatures of the tilapia cultures were generally with the optimal range to grow Nile tilapia, although extreme values were recorded on some farms. Most of the tilapia sampled were apparently healthy. No Francisella sp. was detected in any sample, and Staphylococcus sp. was the most prevalent (from 0% to 64%) bacteria from the three states over time. Low prevalence of Aeromonas sp. was found, from 0% to 4.3%, although the fish pathogen Aeromonas dhakensis was not detected. Sterptococcus iniae was only detected in Chiapas in 2019 at a low prevalence (1.4%), while the major tilapia pathogen S. agalactiae was detected at a high prevalence (from 0% to 59%) in the three Mexican states. This is the first detection of these pathogenic bacteria in rural farms using real‐time PCR and constitutes a great risk for tilapia aquaculture in Mexico, as well as a potential dispersion of these pathogens to other aquaculture areas. [ABSTRACT FROM AUTHOR]

This study aimed to prepare and characterize Nile tilapia (Oreochromis niloticus) waste meal. The experimental design consisted of three treatments (carcass meal, mechanically separated meat meal - MSM, and head meal) and five replications of each treatment. Yield, microbiological quality, pH, water activity, proximate composition, energy value, mineral composition, fatty acid profile, amino acid composition, color, and particle size fractions and the geometric mean particle diameter (GMD) analyses were performed. Data were subjected to ANOVA, and means were compared by Tukey's test at P < 0.05. Carcass, mechanically separated meat, and head meals had a protein content of 56.45%, 78.60%, and 50.33%, respectively, a lipid content of 7.16%, 13.15%, and 4.58%, respectively, and an ash content of 32.61%, 4.26%, and 38.41%, respectively. The mean yield of fish waste meals was 13%. Oleic, palmitic, and linoleic acids were the major fatty acids in the three fish waste meals, and glutamic acid, leucine, lysine, and glycine were the major amino acids. Color analysis showed that lightness (L*) ranged from 55.32 to 77.19, redness (a*) from 4.44 to 4.88, and yellowness (b*) from 4.13 to 9.51. The GMD ranged from 0.37 to 0.99 mm. The results indicate that Nile tilapia waste meals have high nutritional value and adequate pH, water activity, and microbiological quality for use in human nutrition. [ABSTRACT FROM AUTHOR]

In mammals, glial cell derived neurotrophic factor (GDNF) plays a critical role in the self-renewal and maintenance of spermatogonial stem cells (SSCs) in testis and oogenesis in ovary, whilst retinoic acid (RA), the key factor of meiosis initiation, can downregulate its expression. Unlike mammals, two Gdnf replication genes are widely present in teleost fishes, however, our understanding of them is still poor. In the present study, two paralogous gdnf from Nile tilapia (Oreochromis niloticus), namely as Ongdnfa and Ongdnfb , were characterized, and then their cellular expression profiles in testis and ovary and responsiveness to RA treatment at the tissue and cellular levels were investigated. In phylogenetic tree, the Gdnfa and Gdnfb from teleost fishes were clustered into two different subclasses, respectively, and then clustered with the homologs from cartilaginous fish and tetrapods, suggesting that OnGdnfa and OnGdnfb are orthologous to GDNF and paralogous to each other. Ongdnfa is expressed in Sertoli cells and Leydig cells in testis and oocytes in ovary. The expression pattern of Ongdnfb is similar to Ongdnfa. In the ex vivo testicular organ culture, RA down-regulated the expression of Ongdnfa , whereas up-regulated the expression of Ongdnfb (P < 0.05), suggesting that they have differential responsiveness to RA signaling. RA treatment of the cultured cells derived from adult Nile tilapia testis which have the expression of RA receptors (RAR), Ongdnfa and Ongdnfb further confirmed the above result. Collectively, our study suggests that Ongdnfa and Ongdnfb have non-germline expression patterns in testis and germline expression patterns in ovary; furthermore, they have differential responsiveness to RA signaling, implying that they might have differential biological functions. This study broadens and enriches our understanding of fish GDNF homologs and lays foundation for the study of their biological functions in the future. • Two paralogous gdnf (Ongdnfa and Ongdnfb) were characterized from Nile tilapia. • Ongdnfa and Ongdnfb had non-germline expressions in testis. • Ongdnfa and Ongdnfb had germline expressions in ovary. • Ongdnfa and Ongdnfb had differential responsiveness to RA treatment. [ABSTRACT FROM AUTHOR]

Simple Summary: An excessive carbohydrate content in diets can have a negative effect on fish growth. In this study, the effects of berberine supplementation in high-carbohydrate diets on the growth performance, glucose metabolism, bile acid synthesis, liver transcriptome, and intestinal flora of Nile tilapia were investigated. Conclusion: An appropriate amount of berberine can stimulate the synthesis of bile acids by changing the structure of the intestinal flora of tilapia, thus promoting glycolysis and inhibiting gluconeogenesis, then regulating the blood glucose, which is beneficial to the growth of tilapia. This provides the data to improve carbohydrate utilization in tilapia and support the development of high-carbohydrate diets in aquaculture. Berberine is an alkaloid used to treat diabetes. This experiment aimed to investigate the effects of berberine supplementation in high-carbohydrate diets on the growth performance, glucose metabolism, bile acid synthesis, liver transcriptome, and intestinal flora of Nile tilapia. The six dietary groups were the C group with 29% carbohydrate, the H group with 44% carbohydrate, and the HB1-HB4 groups supplemented with 25, 50, 75, and 100 mg/kg of berberine in group H. The results of the 8-week trial showed that compared to group C, the abundance of Bacteroidetes was increased in group HB2 (p < 0.05). The cholesterol-7α-hydroxylase (CYP7A1) and sterol-27-hydroxylase (CYP27A1) activities were decreased and the expression of FXR was increased in group HB4 (p < 0.05). The pyruvate carboxylase (PC) and phosphoenolpyruvate carboxykinase (PEPCK) activities was decreased in group HB4 (p < 0.05). The liver transcriptome suggests that berberine affects carbohydrate metabolic pathways and primary bile acid synthesis pathways. In summary, berberine affects the glucose metabolism in tilapia by altering the intestinal flora structure, enriching differentially expressed genes (DEGs) in the bile acid pathway to stimulate bile acid production so that it promotes glycolysis and inhibits gluconeogenesis. Therefore, 100 mg/kg of berberine supplementation in high-carbohydrate diets is beneficial to tilapia. [ABSTRACT FROM AUTHOR]

Polystyrene nanoplastic (PS-NPs) and Engine oil (EO) pose multiple ecotoxic effects with increasing threat to fish ecosystems. The current study investigated the toxicity of 15 days exposure to PS-NPs and / or EO to explore their combined synergistic effects on Nile tilapia, Oreochromis niloticus (O. niloticus). Hematobiochemical parameters, proinflammatory cytokines, and oxidative stress biomarkers as well as histological alterations were evaluated. The experimental design contained 120 acclimated Nile tilapia distributed into four groups, control, PS-NPs (5 mg/L), EO (1%) and their combination (PS-NPs + EO). After 15-days of exposure, blood and tissue samples were collected from all fish experimental groups. Results indicated that Nile tilapia exposed to PS-NPs and / or EO revealed a significant decrease in almost all the measured hematological parameters in comparison to the control, whereas WBCs and lymphocyte counts were significantly increased in the combined group only. Results clarified that the combined PS-NPs + EO group showed the maximum decrease in RBCs, Hb, MCH and MCHC, and showed the maximum significant rise in interleukin-1β (IL-1β), and interleukin-6 (IL-6) in comparison to all other exposed groups. Meanwhile, total antioxidant capacity (TAC) showed a significant (p < 0.05) decline only in the combination group, whereas reduced glutathione (GSH) showed a significant decline in all exposed groups in comparison to the control. Both malondialdehyde (MDA) and aspartate aminotransferase (AST) showed a significant elevation only in the combination group. Uric acid showed the maximum elevation in the combination group than all other groups, whereas creatinine showed significant elevation in the EO and combination group when compared to the control. Furthermore, the present experiment proved that exposure to these toxicants either individually or in combination is accompanied by pronounced histomorpholgical damage characterized by severe necrosis and hemorrhage of the vital organs of Nile tilapia, additionally extensively inflammatory conditions with leucocytes infiltration. We concluded that combination exposure to both PS-NPs and EO caused severe anemia, extreme inflammatory response, oxidative stress, and lipid peroxidation effects, thus they can synergize with each other to intensify toxicity in fish. [ABSTRACT FROM AUTHOR]

Background: Intestinal barrier is a dynamic interface between the body and the ingested food components, however, dietary components or xenobiotics could compromise intestinal integrity, causing health risks to the host. Gossypol, a toxic component in cottonseed meal (CSM), caused intestinal injury in fish or other monogastric animals. It has been demonstrated that probiotics administration benefits the intestinal barrier integrity, but the efficacy of probiotics in maintaining intestinal health when the host is exposed to gossypol remains unclear. Here, a strain (YC) affiliated to Pediococcus pentosaceus was isolated from the gut of Nile tilapia (Oreochromis niloticus) and its potential to repair gossypol-induced intestinal damage was evaluated. Results: A total of 270 Nile tilapia (2.20 ± 0.02 g) were allotted in 3 groups with 3 tanks each and fed with 3 diets including CON (control diet), GOS (control diet containing 300 mg/kg gossypol) and GP (control diet containing 300 mg/kg gossypol and 108 colony-forming unit (CFU)/g P. pentosaceus YC), respectively. After 10 weeks, addition of P. pentosaceus YC restored growth retardation and intestinal injury induced by gossypol in Nile tilapia. Transcriptome analysis and siRNA interference experiments demonstrated that NOD-like receptors (NLR) family caspase recruitment domain (CARD) domain containing 3 (Nlrc3) inhibition might promote intestinal stem cell (ISC) proliferation, as well as maintaining gut barrier integrity. 16S rRNA sequencing and gas chromatography-mass spectrometry (GC-MS) revealed that addition of P. pentosaceus YC altered the composition of gut microbiota and increased the content of propionate in fish gut. In vitro studies on propionate's function demonstrated that it suppressed nlrc3 expression and promoted wound healing in Caco-2 cell model. Conclusions: The present study reveals that P. pentosaceus YC has the capacity to ameliorate intestinal barrier injury by modulating gut microbiota composition and elevating propionate level. This finding offers a promising strategy for the feed industry to incorporate cottonseed meal into fish feed formulations. [ABSTRACT FROM AUTHOR]

This study aimed to investigate AMR profiles of Aeromonas hydrophila, Salmonella spp., and Vibrio cholerae isolated from Nile tilapia (Oreochromis spp.) (n = 276) purchased from fresh markets and supermarkets in Bangkok, Thailand. A sample of tilapia was divided into three parts: fish intestine (n = 276), fish meat (n = 276), and liver and kidney (n = 276). The occurrence of A. hydrophila, Salmonella, and V. cholerae was 3.1%, 7.4%, and 8.5%, respectively. A high prevalence of these pathogenic bacteria was observed in fresh market tilapia compared to those from supermarkets (p < 0.05). The predominant Salmonella serovars were Paratyphi B (6.4%), followed by Escanaba (5.7%), and Saintpaul (5.7%). All isolates tested positive for the virulence genes of A. hydrophila (aero and hly), Salmonella (invA), and V. cholerae (hlyA). A. hydrophila (65.4%), Salmonella (31.2%), and V. cholerae (2.9%) showed multidrug resistant isolates. All A. hydrophila isolates (n = 26) exhibited resistant to ampicillin (100.0%) and florfenicol (100.0%), and often carried sul1 (53.8%) and tetA (50.0%). Salmonella isolates were primarily resistant to ampicillin (36.9%), with a high incidence of blaTEM (26.2%) and qnrS (25.5%). For V. cholerae isolates, resistance was observed against ampicillin (48.6%), and they commonly carried qnrS (24.3%) and tetA (22.9%). To identify mutations in the quinolone resistance determining regions (QRDRs), a single C248A point mutation of C248A (Ser-83-Tyr) in the gyrA region was identified in six out of seven isolates of Salmonella isolates. This study highlighted the presence of antimicrobial-resistant pathogenic bacteria in Nile tilapia at a selling point. It is important to rigorously implement strategies for AMR control and prevention. [ABSTRACT FROM AUTHOR]

This study was divided into two parts. The first part involved the isolation, and detection of the prevalence and antimicrobial resistance profile of Aeromonas hydrophila, Pseudomonas aeruginosa, and Vibrio species from Nile tilapia fish and marine aquatic water. One hundred freshly dead Nile tilapia fish were collected from freshwater aquaculture fish farms located in Al-Abbassah district, Sharkia Governorate, and 100 samples of marine aquatic water were collected from fish farms in Port Said. The second part of the study focused on determining the in vitro inhibitory effect of dual-combination of AgNPs-H2O2 on bacterial growth and its down regulatory effect on crucial virulence factors using RT-PCR. The highest levels of A. hydrophila and P. aeruginosa were detected in 43%, and 34% of Nile tilapia fish samples, respectively. Meanwhile, the highest level of Vibrio species was found in 37% of marine water samples. Additionally, most of the isolated A. hydrophila, P. aeruginosa and Vibrio species exhibited a multi-drug resistance profile. The MIC and MBC results indicated a bactericidal effect of AgNPs-H2O2. Furthermore, a transcriptional modulation effect of AgNPs-H2O2 on the virulence-associated genes resulted in a significant down-regulation of aerA, exoU, and trh genes in A. hydrophila, P. aeruginosa, and Vibrio spp., respectively. The findings of this study suggest the effectiveness of AgNPs-H2O2 against drug resistant pathogens related to aquaculture. [ABSTRACT FROM AUTHOR]

Dayak onion (Eleutherine bulbosa (Mill.) Urb.) has the potential to be an immunostimulant to benefit fish health. This study aimed to evaluate the effectiveness of dietary supplementation with the powder and crude ethanol extracts of Dayak onion on the hematology and immune response parameters of Nile tilapia challenged with Aeromonas hydrophila. The research used a completely randomized design with six treatments and three replications. Nile tilapias were fed with Dayak onion (w/v) consisting of powders of 5% (P5), 10% (P10), and 15% (P15), while crude extract was 0.5% (E05) and given during rearing for 30 days. Positive control (C+) and negative control (C-) were used without Dayak onion. Nile tilapia in treatment C+, P5, P10, and P15 were injected with A. hydrophila 106 CFU mL-1, while that in treatment C- was injected with phosphate buffered saline (PBS) intramuscularly. The results showed that the dietary with 15% powder and 0.5% crude extract significantly improved the hematology and immune response parameters compared to the control after the challenge against A. hydrophila (P<0.05). Dayak onion supplementation effectively increased the health status based on hematology and immune response parameters of Nile tilapia against A. hydrophila infection. [ABSTRACT FROM AUTHOR]

Nile tilapia [Oreochromis niloticus (Linnaeus, 1758)] is a widespread invasive fish, now present in lakes, rivers, and reservoirs around the world, and its dominance has led to serious ecological problems in many freshwater systems. However, little is known about its effect on macrophyte-dominated lake ecosystems. We conducted a 10-week mesocosm experiment to test the impact of tilapia on phytoplankton and water quality in model ecosystems with submerged macrophytes [Vallisneria natans (Lour.) Hara] and the presence and absence of tilapia. Tilapia led to an increase in concentrations of total phosphorus, total nitrogen, total dissolved nitrogen, ammonia nitrogen, and total suspended solids and had negative impact on submerged macrophyte and light intensity, thus causing an overall deterioration in water quality. Tilapia increased the abundance of rotifers and changed the zooplankton community structure. Tilapia increased the total biomass of phytoplankton but the effect depended on the phytoplankton size, i.e., the overall proportion of micro-phytoplankton increased, while that of pico-phytoplankton decreased. Thus, tilapia also caused changes in the phytoplankton community structure. Our research shows that tilapia deteriorates water quality and modifies phytoplankton and zooplankton Communities of shallow lakes. [ABSTRACT FROM AUTHOR]

To understand the role of myo-inositol oxygenase (miox) in the osmotic regulation of Nile tilapia, its expression was analyzed in various tissues. The results showed that the expression of miox gene was highest in the kidney, followed by the liver, and was significantly upregulated in the kidney and liver under 1 h hyperosmotic stress. The relative luminescence efficiency of the miox gene transcription starting site (−4,617 to +312 bp) under hyperosmotic stress was measured. Two fragments (−1,640/−1,619 and −620/−599) could induce the luminescence activity. Moreover, the −1,640/−1,619 and −620/−599 responded to hyperosmotic stress and high-glucose stimulation by base mutation, suggesting that osmotic and carbohydrate response elements may exist in this region. Finally, the salinity tolerance of Nile tilapia was significantly reduced after the knocking down of miox gene. The accumulation of myo-inositol was affected, and the expression of enzymes in glucose metabolism was significantly reduced after the miox gene was knocked down. Furthermore, hyperosmotic stress can cause oxidative stress, and MIOX may help maintain the cell redox balance under hyperosmotic stress. In summary, MIOX is essential in osmotic regulation to enhance the salinity tolerance of Nile tilapia by affecting myo-inositol accumulation, glucose metabolism, and antioxidant performance. NEW & NOTEWORTHY:Myo-inositol oxygenase (MIOX) is the rate-limiting enzyme that catalyzes the first step of MI metabolism and determines MI content in aquatic animals. To understand the role of miox in the osmotic regulation of Nile tilapia, we analyzed its expression in different tissues and its function under hyperosmotic stress. This study showed that miox is essential in osmotic regulation to enhance the salinity tolerance of Nile tilapia by affecting myo-inositol accumulation, glucose metabolism, and antioxidant performance. [ABSTRACT FROM AUTHOR]

The present study was carried out to investigate the interactive effect of stocking density and diets supplemented with essential oils and or probiotic on the growth performance of juveniles Nile tilapia (Oreochromis niloticus), water quality parameters, intestinal morphology, and protection against Aeromonas hydrophila infection of Oreochromis niloticus. Total number of 640 O. niloticus fish (14.2 ± 0.95 g) were used in our work were allotted into eight groups with three replicates with two stocking densities (36 fish m-3 and 72 fish m-3) and four diets (control, Probiotic (Sanolife PRO-F®), Essential oils (EOs) blend (Super Immune®) and mix of Probiotic (Sanolife PRO-F®) and EOs blend (Super Immune®) respectively for 14 weeks and subsequently, challenged with A. hydrophila. The fish raised at the low stocking density exhibited increased weight gain, feed intake and specific growth rate compared with those raised at the high stocking density. Probiotic and/or EOs blend dietary supplementation improved Nile tilapia weight gain, daily gain, specific growth rate, total feed intake and feed conversion ratio. The water quality metrics' readings throughout the experiment all stayed within acceptable ranges for tilapia production despite the density increase. The fish raised at the low stocking density and received diet supplemented with mix of probiotic and EOs showed marked increased length of intestinal villi compared with the other groups. The EOs blend promoted a better relative percent of survival with percentage of 100 % after challenge by A. hydrophila. It could be concluded that using EOs blend (Super Immune) and/or Probiotic (Sanolife PRO-F) as a dietary supplement for tilapia fingerlings would be a good choice due to their effective growth promoting, antibacterial effect and their positive impacts on fish intestinal morphology. [ABSTRACT FROM AUTHOR]

Regular monitoring of the water quality and heavy metal concentration in edible fish from the Pulangi Lake - an artificial lake in Bukidnon, the Philippines - has not yet been established. This study analyzed the water quality of the Pulangi Lake and assessed the associated risks of heavy metals cadmium (Cd), chromium (Cr), and lead (Pb) in Nile tilapia (Oreochromis niloticus) harvested from the lake during the dry season. Key informant interviews (KII) were also conducted to gather relevant information about the lake. The physico-chemical analysis of the surface water revealed high fecal coliform levels, exceeding the standard limit by more than 100%, but the concentrations of Cd, Cr, and Pb were below the standard limit. However, the Cr concentration in tilapia (0.2430-1.7870 mg/kg) exceeded the permissible limit of 0.05 mg/kg set by the Food and Agriculture Organization and the World Health Organization. Low concentrations of Cd (0.0270-0.1140 mg/kg) and Pb (0.0360-0.4350 mg/kg) were observed. The risk assessment of these individual heavy metals measured from tilapia and its combined impacts showed no potential non-carcinogenic effects based on the estimated target hazard quotient (THQ < 1) and hazard index (HI < 1). However, based on the permissible target cancer risk (1 x 10-6 to 1 x 10-4), tilapia from the Pulangi Lake should be reexamined as it appears that - in terms of Cd and Cr - the probability relating to contamination problem can occur. The present study can be used as baseline data for risk management. [ABSTRACT FROM AUTHOR]

Striped wallago catfish (Wallago leerii), a freshwater catfish species with high economic value, has been extensively exploited in Indonesia. Therefore, domestication is necessary to ensure the sustainability of this species through a hormonal approach. This research aimed to evaluate hormonal treatments on the bioreproductive and physiological parameters of broodstocks during domestication. Collected broodstocks from Kampar River, Indonesia, were adapted in semiconcrete ponds and fed daily with live tilapia (Oreochromis niloticus) and bonylip barb (Osteochilus vittatus) fingerlings at a rate of 5% weight of biomass per day. Selected broodstocks (length:55.59 ± 5.21 cm; weight:1.60 ± 0.53 kg) were randomly divided into three experimental grdoups with four replicates each. Each group was injected with human chorionic gonadotropin (HCG), Spawnprime™, and Ovaprim™ hormones (0.1 mL/kg body weight). Egg sizes, fecundity, fertility rate, hatching rate, embryo development, and estradiol, glucose, hemoglobin, and cortisol levels were analyzed. HCG and Ovaprim™ treatment led to significant improvements in egg diameter compared to Spawnprime™ (p < 0.05). This finding was supported by an increase in estradiol levels (p < 0.05). However, HCG and Ovaprim™ did not reach optimal performance, as shown by the low fertility rates (9.83–12.33%), hatching rates (24.06–34.17%), and larval abnormalities. Hormone injection did not significantly impact the glucose level for all treatments (p > 0.05). On the other hand, hemoglobin was significantly lower in the HCG- and Ovaprim-treated broodstocks at the end of the experiment (p < 0.05), while the other treatments did not show significant differences (p > 0.05). Significant differences in cortisol levels were identified in all treatments (p < 0.05), except for the HCG-treated broodstocks (p > 0.05). In conclusion, HCG and Ovaprim™ improved striped wallago catfish gonadal maturation up to artificial spawning, whereas Spawnprime™ had a weak effect. The usage of hormones on gonadal maturation impacted some of their physiological parameters. [ABSTRACT FROM AUTHOR]

In Egypt, the temperature of the water fluctuates drastically, reaching a daytime high of 25 °C and a nighttime low of 15 °C, respectively, in the spring and the fall. To understand the mechanism behind fish kill in fish farms, an indoor experiment was conducted wherein 240 Nile tilapia weighing 24 ± 2.5 g were stocked in 12 glass aquaria (20 fish/aquarium). Water temperature was regulated throughout the day at 27 ± 1.5 °C for 12 h from 8:00 a.m. to 8:00 p.m. and at 18 ± 1.5 °C for the remaining 12 h. Fish samples (mucus and tissues) were collected four times with a week interval. Proinflammatory tumor necrosis factor-α and interleukin (IL)-1β were decreased during the 4 weeks, while anti-inflammatory IL-10 was highly upregulated during the first week and then decreased compared to the control. Heat shock protein-70 was significantly raised, but IL-8 was unaffected. The gene expressions of antioxidant enzymes catalase and glutathione peroxidase were markedly elevated in the first week and then decreased linearly until they no longer differed from the control group. Mucus lysozyme significantly decreased in weeks 1 and 2 and then began to increase in weeks 3 and 4. Every week, Aeromonas hydrophila infection resulted in clinical signs that were delayed by over 2 days compared to the control group. The mortality rate increased from 35 to 40%, and bacteria were isolated at a rate of 61.54 to 75% from the surviving fish, compared to a rate of 41.67% in the control group. Fluctuations in water temperature suppress the immunity of Nile tilapia, making them vulnerable to bacterial infection. [ABSTRACT FROM AUTHOR]

The primary goal of this trial was to examine how Paulownia leaf extract (PLE) dietary supplementation affected performance, feed utilization and efficiency, redox status, immunological responses, intestinal microbial content, and disease resistance of Oreochromis niloticus. Nile tilapia fry (0.52 ± 0.19 g) were fed four formulated diets enriched with graded amounts of PLE at 0.0, 0.25, 0.5, and 1 g kg−1 diet, respectively, for 60 days. At the end of the feeding trial, fish were intraperitoneal injected with Aeromonas hydrophila then the survival percentage was recorded daily and calculated mortality rate in all treated groups for 14 days. The performance findings showed that enriched tilapia diets with modest levels of PLE (0.25 or 0.5 g kg−1) substantially enhanced performance, consumed feed, feed efficiency, and feed utilization parameters compared to the control and other treatment groups, whereas the total serum protein and globulin concentrations were significantly (P < 0.001) higher in the fish provided a small quantity of PLE (2.5 g kg-1 diet) than in the control group. Compared to other treatment groups, all estimated liver enzymes and kidney function indicators improved significantly (P < 0.001) at PLE0.5, followed by PLE2.5, whereas the digestive enzymes' activity increased significantly (P < 0.001) with increasing PLE level up to 0.5 g/kg diet compared to the un-supplemented group. In the same context, enriched tilapia diets with 0.5 g PLE/kg significantly (P < 0.001) boosted redox status and innate immune parameters as compared to other groups. Furthermore, increased PL inclusion levels in tilapia diets significantly (P < 0.05) increased crude protein and ash contents while decreasing fat levels in fish flesh. Moreover, fortified tilapia diets with high PLE levels significantly enhanced the survival percentage and diminished the development of all gram-negative intestinal microbial content. Finally, the results strongly recommend enriched tilapia diets with 0.25 or 0.5 g /Kg for promoting performance and health status. [ABSTRACT FROM AUTHOR]

Due to their peculiar physicochemical properties, nanoparticles (NPs) have the potential to have a detrimental impact on molecular (proteins and nucleic acids), subcellular, cellular, tissue, and organism levels. However, available works on the harmful effects of the water-borne ionizable NPs, such as aluminum oxide nanoparticles (ALNPs) on fish are scarce. Therefore, the toxic impacts of ALNPs on hematological, biochemical, and immunological responses in Nile Tilapia fish were investigated in this work. Additionally, the possible benefits of the promising chamomile essential oil (CEO) as dietary supplement in alleviating such impacts were also targeted. For this, four fish groups were used. The control group received only the basic diet, CEO group (basic diet + 2 mg CEO/kg diet), ALNP group (basic diet with exposure to5.08 mg ALNPs/L water, and ALNPs/CEO group (basal diet + 2 mg CEO/kg diet + 5.08 mg ALNPs/L). Fish exposed to ALNPs showed declines in the growth performance and fish survivability in addition to changes seen in the hematological and protein profiles and stress variables. Along with decreased resistance to the Aeromonas hydrophila challenge, there were also substantial decreases in all humoral immune indicators. In addition to increased mRNA expressions of immune genes in the hepatic tissues. CEO significantly modulated the toxic effects of ALNPs suggesting its utilization as a valuable dietary supplement for fish [ABSTRACT FROM AUTHOR]