Stevioside mitigates lead toxicity in thinlip mullet juveniles: Impacts on growth, metabolism, and immune function.

This study investigates the impact of varying concentrations of stevioside in the presence of lead (Pb) exposure on multiple aspects of thinlip mullet (Liza ramada) juveniles. Over 60 days, a total of 540 juvenile L. ramada with an initial weight of 3.5 ± 0.13 g were evenly distributed into six groups, each consisting of three replicates. The experimental diet consisted of varying levels of stevioside (150, 250, 350, and 450 mg/kg diet), with a consistent concentration of lead (Pb) set at 100 µg/kg diet. Stevioside demonstrated a positive influence on growth parameters, with the 450 mg/kg +Pb treatment showing the highest values. Biochemical parameters remained stable, but lead-exposed fish without stevioside displayed signs of potential liver damage and metabolic issues. Stevioside supplementation, especially at higher doses (≥250 mg/kg), reversed these negative effects, restoring biochemical markers to healthy control levels. Lead exposure significantly suppressed antioxidant enzyme activities, but co-administration of stevioside exhibited a dose-dependent protective effect, with 250, 350, and 450 mg/kg groups showing activities comparable to the healthy control. Lead-exposed fish without stevioside demonstrated attenuation of the immune response, but stevioside supplementation reversed these effects, particularly at ≥250 mg/kg. Stev (≥250 mg/kg) reduced IL-1ß and hepcidin expression, contrasting dose-dependent upregulation in lower dosages and lead-only group. Histological examinations of the intestine and liver supported these findings. In conclusion, stevioside, especially at 450 mg, positively impacted growth, biochemical parameters, antioxidant activity, immune response, and gene expression in L. ramada exposed to lead, suggesting its potential to mitigate lead toxicity in aquaculture. Additional research is warranted to investigate the long-term impacts of stevioside supplementation and its prospective implementation in aquaculture.

Dietary effects of Saccharomyces cerevisiae and Allium sativum on growth, antioxidant status, hepatic and intestinal histoarchitecture, expression of growth- and immune-related genes, and resistance of Oreochromis niloticus to Aeromonas sobria.

This study investigated the benefits of yeast, Saccharomyces cerevisiae and/or garlic, Allium sativum supplementation in diets of Nile tilapia with regard to growth, antioxidant status, hepatic and intestinal histoarchitecture, expression of growth- and immune-related genes, and resistance to Aeromonas sobria infection. Fish (with an initial weight of 9.43 ± 0.08 g) were allocated to twelve hapas, organized into four triplicate treatment groups defined as control (no supplementation), yeast (4 g/kg diet), garlic (30 g/kg diet), and a mixture of both. This trial continued over a 60-day feeding period. Results revealed that combined treatment (yeast + garlic) demonstrated the most promising outcomes regarding growth, with significantly higher final body weights, weight gains, and specific growth rates compared to other groups. Moreover, this combination enhanced hepatic antioxidant status, as evidenced by elevated levels of reduced glutathione and activities of catalase and superoxide dismutase enzymes, reflecting improved defense against oxidative stress. Histological assessments of the livers and intestines demonstrated structural enhancements in yeast and garlic treatments, suggesting improvements in organ health. In comparison to the control, the gene expression analyses unveiled increased expression of growth-related (igf-1 and ghr1) and immune-related (il-10, lyz, and hep) genes in the test groups, indicating a possible reinforcement of the growth and immune responses. The combined treatment also showed the highest resistance to A. sobria infection, as evidenced by improved survival rates and lower mortality compared with the other groups. These findings highlight the benefits of a combination of both yeast and garlic as a dietary supplementation regimen. In conclusion, this study suggests that the combined treatment regimen could be considered an effective strategy to promote the health and productivity of Nile tilapia under production conditions.

Evaluation of different probiotics on growth, body composition, antioxidant capacity, and histoarchitecture of Mugil capito.

We investigated the dietary effects of the single application of Saccharomyces cerevisiae, Lactobacillus bulgaricus, and their combination on growth, proximate composition of whole fish body, antioxidant defense, and histoarchitecture of hapa-reared Mugil capito. Healthy fish (Fish weighed = 10.30 ± 0.10 g at first) were randomly allocated into 4 equal groups, each with three replicates. These groups were designed as follows: (1) a group fed a basal diet without probiotics (control), (2) a group fed a diet containing S. cerevisiae (4 g/kg diet), (3) a group fed a diet containing L. bulgaricus (2 g/kg diet), and (4) the last group fed a diet containing a combination of both, all for a duration of 60 days. Probiotic-treated groups showed significantly better growth and nutrition utilization than the control group. Significant differences were observed in the crude fat and crude protein contents among the groups, with the combination group exhibiting the highest levels. However, there were no significant variations in ash content across all groups. The highest hepatic antioxidant capacity (superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPX) enzyme activities) was observed in the combination group. Thiobarbituric acid reactive substance (TBARS) concentrations were decreased significantly in all probiotic groups, suggesting improved oxidative stress resilience in these groups. The histomorphological analysis of the hepatopancreatic tissues revealed well-arranged parenchyma, increased glycogen storage, and melanomacrophage centers in probiotic-treated groups, particularly the combined probiotics group. Furthermore, the probiotic supplementation improved the histoarchitecture of the intestinal villi compared to the control group. To put it briefly, combined dietary administration of these probiotics improved growth, body composition, antioxidant defenses, and hepatic and intestinal health in hapa-reared M. capito, highlighting their promising role in promoting welfare and productivity.

Combined Effects of Yellow Mealworm (Tenebrio molitor) and Saccharomyces cerevisiae on the Growth Performance, Feed Utilization Intestinal Health, and Blood Biomarkers of Nile Tilapia (Oreochromis niloticus) Fed Fish Meal-Free Diets.

Aquafeed quality is the most critical factor for aquaculture sustainability. However, limitations of traditional feed ingredients such as fishmeal (FM) need alternative strategies to ensure the nutritional requirements for aquatic animals. In this trial, four test diets were formulated (2 × 2 factorial design), where FM was incorporated in two diets at 10% with or without Saccharomyces cerevisiae (SC) at 1 g/kg. At the same time, FM was replaced with yellow mealworm (Tenebrio molitor) meal (TM) with or without SC at 1 g/kg. The growth performance indices (final weight, weight gain, and SGR), and the feed utilization indices (FCR and PER) were markedly affected by the protein source (FM or TM) and dietary SC (P < 0.05). The protein source (FM or TM) significantly (P < 0.05) affected the whole-body protein and lipid contents, while the moisture and ash contents were unaffected (P > 0.05) by TM or SC. The growth of the intestinal villi showed a marked increase in both height and branching in the treated groups with SC along the whole length of the intestine. Furthermore, the immune cell infiltration was prominent near the intestinal crypts of the middle intestinal segments in the supplemented groups by SC. Dietary TM and SC revealed improved hepatic parenchyma in the liver tissue better than other groups. The hematological indices, including hemoglobulin, hematocrit, red blood cells, and white blood cells, were markedly affected by dietary SC (P < 0.05). The lysozyme activity and phagocytic index were markedly affected by dietary SC, while phagocytic activity was affected by dietary TM (P < 0.05). The catalase, glutathione peroxidase, and malondialdehyde were markedly affected by the interaction between dietary protein source and SC, while superoxide dismutase was affected by dietary SC (P < 0.05). In conclusion, adding SC could enhance the utilization of TM by Nile tilapia with positive effects on the intestinal and liver histological features and the immune and antioxidative responses.

Dietary effect of soybean lecithin on the growth performance, digestive enzyme activity, blood biomarkers, and antioxidative status of striped catfish, Pangasianodon hypophthalmus.

Soybean lecithin (SBL) is usually added to aquafeed as a lipid source because aquatic animals cannot synthesize phospholipids. Hence, this study aimed to investigate the role of SBL on the growth, nutrient consumption, digestive enzyme activity, blood parameters, and antioxidant capability of striped catfish. The fish were fed on five experimental diets with five grading levels of SBL (0, 2, 4, 6, and 8%) for 60 days. The final weight, weight gain, specific growth rate, feed intake, and protein efficiency ratio were markedly higher in striped catfish treated with 2-4% SBL than the control level (0% SBL). However, the lowest feed conversion ratio was in the fish-fed groups of 4-6% SBL. The carcass lipid content was significantly higher in fish fed 2-4% SBL compared to the control level (0% SBL). The lipase, amylase, and protease activities were significantly increased in the fish fed 2-6% SBL compared to 0% SBL-fed group. The gradually increased levels of SBL improved the structural appearance and increased the intestinal villi length and branching appearance. The triglycerides and total cholesterol were increased in the fish fed with 4, 6, and 8% compared to the control level, with the highest being in the fish fed with 8%. The lysozyme activity was higher in the fish fed with 2, 4, and 6% of SBL compared to the control level, with higher activity in the fish fed with 2 and 4% than 6%. Superoxide dismutase, glutathione peroxidase, and catalase activities were increased in the fish fed with 2, 4, and 6% SBL. The malondialdehyde level was lower in the fish fed with 4-6% SBL compared to the control level. The regression analysis revealed that the optimum dose of SBL is required at 3.65-4.42% for better productivity and health performances in striped catfish.

Dietary Lactobacillus acidophilus ATCC 4356 Relieves the Impacts of Aflatoxin B1 Toxicity on the Growth Performance, Hepatorenal Functions, and Antioxidative Capacity of Thinlip Grey Mullet (Liza ramada) (Risso 1826).

Dietary Lactobacillus acidophilus ATCC 4356 was used to relieve the impacts of aflatoxin B1 toxicity on the performances of Liza ramada. The control diet was without any additives, while the second and third diets were supplemented with aflatoxin B1 at 0.5 and 1 mg/kg. The fourth diet was supplemented with Lb. acidophilus ATCC 4356 at 1 × 106 CFU/mL per kg diet, while the fifth with aflatoxin B1 at 1 mg/kg and Lb. acidophilus ATCC 4356 at 1 × 106 CFU/mL per kg diet. The growth performance markedly increased (p < 0.05) in L. ramada fed Lb. acidophilus ATCC 4356, while aflatoxin B1 at 0.5 and 1 mg/kg groups showed a severe reduction. The red blood cells, hemoglobulin, hematocrit, and white blood cells were markedly increased in L. ramada fed Lb. acidophilus ATCC 4356 while decreased (p < 0.05) in fish fed aflatoxin B1 at 0.5 and 1 mg/kg. The blood total protein and albumin were markedly increased (p < 0.05) in L. ramada fed Lb. acidophilus ATCC 4356 while reduced in aflatoxin B1 at 0.5 and 1 mg/kg groups. The levels of total cholesterol and triglycerides were meaningfully increased in fish of the Lb. acidophilus ATCC 4356 and aflatoxin B1 at 1 mg/kg groups while decreased in aflatoxin B1 at 0.5 and 1 mg/kg groups. Alanine aminotransferase, aspartate aminotransferase, creatinine, and urea levels were markedly decreased (p < 0.05) in fish-fed Lb. acidophilus ATCC 4356 while increased in aflatoxin B1 at 0.5 and 1 mg/kg groups. The highest levels of blood glucose and cortisol were seen in fish contaminated with aflatoxin B1 at 1 mg/kg, while the lowest levels were observed in the fish fed Lb. acidophilus ATCC 4356 group (p < 0.05). The catalase and superoxide dismutase were markedly enhanced in the Lb. acidophilus ATCC 4356 group and severely declined in aflatoxin B1 at 0.5 and 1 mg/kg groups (p < 0.05). The malondialdehyde level was markedly reduced in fish fed Lb. acidophilus ATCC 4356 with or without aflatoxin B1 at 1 mg/kg diets while increased in fish contaminated with aflatoxin B1 at 0.5 and 1 mg/kg (p < 0.05). The control group had lower malondialdehyde levels than the aflatoxin B1 at 1 mg/kg group and higher than the Lb. acidophilus ATCC 4356 with or without aflatoxin B1 toxicity (p < 0.05). Histopathological examination revealed impaired intestines and livers in fish contaminated with aflatoxin B1 while Lb. acidophilus ATCC 4356 relieves the inflammation and protected the intestines and livers. In conclusion, dietary Lb. acidophilus ATCC 4356 is recommended to relieve the impacts of aflatoxicosis-induced hepatorenal failure and oxidative stress in L. ramada.

Isatis phytogenic relieved atrazine induced growth retardation, hepato-renal dysfunction, and oxidative stress in Nile tilapia.

The influence of herbicides causes health and economic loss, which requires innovative solutions to sustain the aquaculture industry. In this regard, dietary isatis is included in Nile tilapia diets to relieve atrazine (ATZ)-induced growth retardation, hepato-renal dysfunction, and oxidative stress. The first and second groups offered the control diet (control), while the third and fourth groups offered the isatis supplemented diet (1%). Meantime, half of the water was replaced and mixed with ATZ (1.39 mg/L) in the second and fourth groups for 30 days. The group of fish delivered isatis had significantly enhanced FBW, WG, and SGR, while fish intoxicated with ATZ had meaningfully impaired growth behavior (p < 0.05). Further, the FCR was improved by isatis, and ATZ resulted in the worst FCR among the groups. Interestingly fish fed isatis and exposed with ATZ (88.89%) had a higher survival rate than fish exposed with ATZ without isatis feeding, and both are lower than the control (97.78%) (p < 0.05). The histological structure in the isatis-treated groups showed distinguished enhancement and branching of the intestinal villi. The intestine of ATZ-treated fish revealed damage and inflammatory cell infiltration in the intestinal mucosa with separation of lining epithelium. Generally, fish fed isatis and intoxicated with ATZ had lower uric acid, urea, creatinine, ALT, and AST and higher total protein, globulin, and albumin than fish exposed with ATZ without feeding with isatis (p < 0.05). Markedly, fish-fed isatis had the highest SOD, CAT, GPx, and the lowest MDA level compared to the other groups (p < 0.05). Meanwhile, fish exposed with ATZ had the worst SOD, CAT, GPx, and the highest MDA level compared to the other groups (p < 0.05). In summary, dietary isatis relieved ATZ induced growth retardation, hepato-renal dysfunction, and oxidative stress in Nile tilapia.

Growth Performance, Antioxidative Capacity, and Intestinal Histomorphology of Grey Mullet (Liza ramada)-Fed Dietary Zinc Nanoparticles.

Zinc is one of the essential microelements involved in vital physiological and biological functions in the fish body. The study evaluated the growth performance, antioxidative capacity, and intestinal histomorphology of Grey Mullet (Liza ramada)-fed dietary zinc nanoparticles (ZnO-NPs) at 0, 10, 20, and 40 mg/kg for the first time. The final weight and specific growth rate (SGR) of Grey Mullet-fed dietary ZnO-NPs at 20 and 40 mg/kg were meaningfully enhanced (p < 0.05). Further, the weight gain (WG) was significantly higher in fish treated with ZnO-NPs than the control, and fish fed 20-40 mg/kg had the highest WG (p < 0.05). The feed conversion ratio (FCR) was meaningfully reduced in fish fed 20-40 mg ZnO-NPs/kg (p < 0.05). The histomorphology of the intestines revealed a significant improvement in villus height, villus width, and goblet cells by ZnO-NPs. The lysozyme activity, phagocytic activity, and phagocytic index showed higher levels in Grey Mullet-fed dietary ZnO-NPs at 20 mg/kg than fish fed 0, 10, and 40 mg/kg (p < 0.05). Superoxide dismutase (SOD) and catalase (CAT) were markedly improved in Grey Mullet treated with ZnO-NPs compared with the control, and the group of fish treated with 20 mg/kg had the highest SOD and CAT (p < 0.05). Glutathione peroxidase (GPx) was significantly higher in fish fed 20-40 mg/kg ZnO-NPs than fish fed 0-10 mg/kg and fish fed 40 mg ZnO-NPs/kg showing the highest GPx value (p < 0.05). The concentration of malondialdehyde was markedly lowered in Grey Mullet fed ZnO-NPs at varying levels (p < 0.05). Based on the overall results, the regression analysis suggests that ZnO-NPs can be included at 24.61-35.5 mg/kg for the best performances of Grey Mullet.

Studying the Influence of Copper on the Growth Behavior, Antioxidative Status, and Histology of the Intestine and Liver of Striped Catfish (Pangasianodon hypophthalmus).

Microelements are well recognized as an essential approach in the field of aquaculture nutrition. Thus, this study aimed to evaluate copper (Cu) inclusion (0, 0.5, 1, and 2 mg/kg) on Striped catfish performances. Fish fed the Cu-incorporated diets for 60 days, then their growth behavior, antioxidative capacity, and intestinal and liver histological features were evaluated. The results showed a marked enhancement in Striped catfish's growth behavior fed 1-2 mg/kg of Cu, as shown by the final weight, weight gain, and specific growth rate. The feed and protein efficiency ratios were significantly affected by Cu in a dose-dependent manner. The highest level of Cu was accumulated in the whole body, muscle, liver, and gills of fish fed 2 mg/kg of Cu. The carcass composition of Striped catfish showed higher protein content in groups received 0.5, 1, and 2 mg/kg Cu in a linear and quadratic manner (p=0.001). The ash content was quadratically increased in Striped catfish fed 2 mg/kg Cu (p=0.001). However, no marked effects were observed on the moisture and lipid contents and the somatic indices (p>0.05). The incorporation of Cu showed meaningfully increased superoxide dismutase, catalase, and glutathione peroxidase but decreased malondialdehyde level in Striped catfish. The villous height exhibited visible growth and branching with increased doses of Cu without a significant increase in the goblet cells. No abnormal features were observed in the liver and hepatocytes of fish treated with Cu. It can be concluded that Cu is required at 1-2 mg/kg for better performances of Striped catfish.

Mannan Oligosaccharide Enhanced the Growth Rate, Digestive Enzyme Activity, Carcass Composition, and Blood Chemistry of Thinlip Grey Mullet (Liza ramada).

Mannan oligosaccharide (MOS) is prebiotic with high functionality in aquaculture. The current study investigated the potential roles of MOS on the growth performance, digestive enzyme activity, carcass composition, and blood chemistry of Thinlip grey mullet (Liza ramada). Four tested diets with 34.49% crude protein and 6.29% of total lipids were prepared and fortified with 0, 0.5, 1, and 2% MOS. Fish of initial weight = 5.14 ± 0.11 g/fish were distributed in 12 hapas (0.5 × 0.5 × 1 m) at 15 fish per hapa (triplicates) and fed the test diets to the satiation level two times a day (08:00 and 15:00) for eight weeks. At the end of the trial, all fish were weighed individually for growth performance calculation. Blood was collected to check blood chemistry traits, and intestines were dissected for digestive enzyme analysis. Fish treated with MOS had marked enhancement in the final body weight, feed conversion ratio, protein gain, and protein retention regardless of inclusion dose (p < 0.05). The weight gain, specific growth rate, and protein efficiency ratio were meaningfully enhanced by including MOS at 0.5 and 1%, followed by fish fed with 2% MOS, while the lowest values were in the control group (p < 0.05). Insignificant influences of MOS were seen on the chemical composition of carcass components (moisture, crude protein, total lipids, and ash) (p > 0.05). Fish treated with MOS at 0.5 and 1% had marked enhancement in the amylase, lipase, and protease activities regardless of inclusion dose (p < 0.05). The blood total protein and albumin levels were meaningfully enhanced by including MOS at 0.5 and 1%, followed by fish fed with 2% MOS, while the lowest values were in the control group (p < 0.05). The blood globulin was significantly enhanced in fish fed 1% MOS than fish treated with 0, 0.5, and 2% of MOS (p < 0.05). The blood lysozyme activity was meaningfully enhanced by including MOS at 1%, followed by fish treated with 0.5 and 2%, while the lowest values were in the control group (p < 0.05). Phagocytic activity and phagocytic index were markedly improved in fish treated with 1 and 2% MOS, followed by those fed 0.5% compared with fish fed MOS-free diet (p < 0.05). Superoxide dismutase and glutathione peroxidase were markedly improved in fish treated with 1, and 2% MOS, followed by those fed 0.5% compared with fish fed MOS-free diet (p < 0.05). Dietary MOS (0.5, 1, and 2%) meaningfully enhanced catalase activity while decreased the malondialdehyde concentration (p < 0.05). In summary, dietary MOS is required at 0.5-1% for enhancing the growth rate, feed efficiency, digestive enzyme activity, blood chemistry, and antioxidative capacity of grey mullet.

Selenium nanoparticles are required for the optimum growth behavior, antioxidative capacity, and liver wellbeing of Striped catfish (Pangasianodon hypophthalmus).

Selenium (Se) is a multifunctional trace element required in specific amounts for the optimal growth of aquatic finfish species. For this reason, this study investigated the effect of Se nanoparticles on the growth behavior, antioxidative capacity, and liver wellbeing of Striped catfish (Pangasianodon hypophthalmus). Striped catfish fed varying Se nanoparticles levels (0. 0.5, 1, and 2 mg/kg) in triplicate units and kept for 60 days. Striped catfish delivered dietary Se nanoparticles had markedly increased growth performance, specific growth rate (SGR), consumed feed, and protein efficiency ratio but reduced feed conversion ratio (FCR). The whole body, liver, muscle, and gills have higher Se accumulation levels in fish that received Se nanoparticles than the control with the highest level in fish fed 2 mg/kg. The carcass composition showed higher protein content in fish fed 1 and 2 mg/kg (p = 0.001 and 0.001) and higher ash content (p = 0.001 and 0.002) in fish fed 2 mg/kg than the remaining groups. Superoxide dismutase was meaningfully activated in Striped catfish delivered 1 and 2 mg Se nanoparticles/kg compared with the control (p < 0.05). Also, catalase and glutathione peroxidase activities were higher, and malondialdehyde level was lower in Striped catfish fed Se nanoparticles at 0.5, 1, and 2 mg/kg than the control (p < 0.05). The villi exhibited a visible increase in both height and branching with an increased level of Se nanoparticles in addition to the increased number of goblet cells. The Se nanoparticles-treated fish revealed dose-dependent modifications fluctuated from diffuse fatty vacuolization in hepatocytes with eccentric pyknotic hepatocytes nuclei. In conclusion, Se nanoparticles are required for the optimum growth behavior, antioxidative capacity, and liver wellbeing of Striped catfish. Based on SGR and FCR data's regression analysis, Se nanoparticles are recommended at 1.02-1.11 mg/kg diet.

The influence of coconut oil on the growth, immune, and antioxidative responses and the intestinal digestive enzymes and histomorphometry features of Nile tilapia (Oreochromis niloticus).

The trials of finding non-conventional and alternative aquafeed ingredients are increasing. In this sense, this study evaluated the influence of coconut oil on the growth, feed utilization, immune, and antioxidative responses of Nile tilapia. Five test diets were formulated by mixing coconut oil with the other ingredients at 0, 1, 2, 3, and 4% of the total ration and presented for tilapia for 60 successive days. The final weight, SGR, weight gain (WG), and feed intake were superior in fish delivered 2% of coconut oil (P < 0.05). Concurrently, fish that received 2% coconut oil had lower FCR and higher PER than fish of the control and 4% groups (P < 0.05). Higher lipase activity was observed in fish of 2% and 3% levels than the remaining groups (P < 0.05). Besides, the amylase and protease activities of fish in 1%, 2%, and 3% groups were higher than the 0% level (P < 0.05). The total blood cholesterol, RBCs, and PCV showed higher values in Nile tilapia fed 2% and 3% coconut oil (P < 0.05). The lysozyme and phagocytic activities were higher in fish fed 2% and 3% levels than the control (P < 0.05), while the phagocytic index in 2% and 3% levels was higher than 0% and 4% levels. Furthermore, SOD and CAT were higher in fish fed 1%, 2%, and 3% than fish fed 0% and 4% levels while GSH was higher in fish of 1%, 2%, and 3% than fish fed 0% level (P < 0.05). However, the MDA level was markedly lower in fish fed 25, 3%, and 4% coconut oil than the 0% level (P < 0.05). The intestine's histological structure in all groups appeared normal, forming of intestinal villi projecting from the intestinal wall. Also, the structure of the hepatopancreas had a normal architecture in all groups. To sum up, the inclusion of coconut oil at 2 to 3% is recommended as a replacer for fish oil in Nile tilapia diets.

Marine-Derived Chitosan Nanoparticles Improved the Intestinal Histo-Morphometrical Features in Association with the Health and Immune Response of Grey Mullet (Liza ramada).

Marine-derived substances are known for their beneficial influences on aquatic animals' performances and are recommended to improve intestinal health, immunity, and anti-oxidative status. The present study investigates the role of chitosan nanoparticles on the intestinal histo-morphometrical features in association with the health and immune response of Grey Mullet (Liza ramada). Chitosan nanoparticles are included in the diets at 0, 0.5, 1, and 2 g/kg and introduced to fish in a successive feeding trial for eight weeks. The final body weight (FBW), weight gain (WG), and specific growth rate (SGR) parameters are significantly increased while feed conversion ratio (FCR) decreases by chitosan nanoparticles compared to the control (p < 0.05). The morphometric analysis of the intestines reveals a significant improvement in villus height, villus width, and the number of goblet cells in chitosan-treated groups in a dose-dependent manner. Additionally, there is a positive correlation between the thickness of the enterocyte brush border and the chitosan dose, referring to an increasing absorptive activity. Histologically, the intestinal wall of Grey Mullet consists of four layers; mucosa, sub-mucosa, tunica muscularis (muscular layers), and serosa. The histological examination of the L. ramada intestine shows a normal histo-morphology. The epithelial layer of intestinal mucosa is thrown into elongated finger-like projections, the intestinal villi. The values of hemoglobin, hematocrit, red blood cells (RBCs), total protein (TP), albumin, and globulin are significantly increased in fish fed 1, and 2 g/kg of chitosan nanoparticles compared to fish fed 0 and 0.5 g/kg (p < 0.05). The highest levels of TP and albumin are observed in fish fed 1 g/kg diet (p < 0.05). The lysozyme activity and phagocytic index are significantly enhanced by feeding chitosan nanoparticles at 0.5, 1, and 2 g/kg, whereas the phagocytic activity is improved in fish fed 1 and 2 g/kg (p < 0.05). The highest lysozyme activity and phagocytic index are observed in fish fed 1 g/kg. SOD is significantly activated by feeding chitosan nanoparticles at 1 g/kg. Simultaneously, glutathione peroxidase (GPx) and catalase (CAT) activities also are enhanced by feeding chitosan at 1 and 2 g/kg, compared to fish fed 0 and 0.5 g/kg (p < 0.05). The highest GPx and CAT activities are observed in fish fed 1 g/kg (p < 0.05). Conversely, the malondialdehyde (MDA) levels are decreased by feeding chitosan at 1 and 2 g/kg, with the lowest being in fish fed 1 g/kg (p < 0.05). To summarize, the results elucidate that L. ramada fed dietary chitosan nanoparticles have a marked growth rate, immune response, and anti-oxidative response. These improvements are attributed to the potential role of chitosan nanoparticles in enhancing intestinal histo-morphometry and intestinal health. These results soundly support the possibility of using chitosan nanoparticles at 1-2 g/kg as a feasible functional supplement for aquatic animals.

The impact of menthol essential oil against inflammation, immunosuppression, and histopathological alterations induced by chlorpyrifos in Nile tilapia.

Chlorpyrifos (CPF) is one of the predominant water pollutants associated with inflammation and immunodepression in aquatic animals. In this study, menthol oil (MNT) impacted the immunity, antioxidative, and anti-inflammatory responses against CPF toxicity in Nile tilapia. Fish fed two diets with or without MNT and placed in four groups (control, CPF, MNT, and CPF/MNT). After 30 days, fish fed MNT displayed higher growth performance and lower FCR than CPF-intoxicated fish without feeding MNT (P < 0.05). The survival rate of fish was reduced in the CPF group without MNT feeding (P < 0.05). Blood Hb, PCV, RBCs, and WBCs were decreased in fish by CPF toxicity, while the highest Hb, PCV, RBCs, and WBCs were observed in fish fed MNT followed by those fed the control without CPF toxicity (P < 0.05). Fish fed MNT had the highest total protein, albumin, and globulin, as well as the lowest urea, bilirubin, and creatinine after 15 and 30 days. However, fish under CPF toxicity had the most inferior total protein, albumin, and globulin, as well as the highest urea, bilirubin, and creatinine among the groups (P < 0.05). The enzyme activities of ALP and ALT displayed low levels by MNT with or without CPF exposure than fish fed without MNT with or without CPF exposure after 15 and 30 days (P < 0.05). The lysozyme and phagocytic activities displayed reduced levels by CPF without MNT feeding after 15 and 30 days, while increased activities were noticed by MNT feeding without CPF toxicity followed by fish fed MNT with CPF toxicity (P < 0.05). The transcription of CAT and GPX genes displayed upregulated levels in tilapia fed MNT and exposed to CPF (P < 0.05). Also, CPF toxicity increased the transcription of the IFN-γ gene but decreased the IL-8 and IL-1ß genes. The transcription of HSP70 displayed lower levels (P < 0.05) by CPF without supplementing MNT than fish fed MNT and exposed to CPF. Histopathological analysis revealed that inflammation existed in the liver, gills, and intestine of tilapia due to CPF toxicity while MNT protected tissues from inflammation. To conclude, MNT activated the immunity, antioxidative, and anti-inflammatory responses of Nile tilapia under CPF toxicity.

Copper Nanoparticles Mitigate the Growth, Immunity, and Oxidation Resistance in Common Carp (Cyprinus carpio).

The present investigation aimed to evaluate the influence of copper nanoparticles (Cu-NPs) on the growth, immunity, and oxidation resistance of common carp (3.02 ± 0.01 g, initial mean weight ± S.E.). Five groups of fish fed diets with Cu-NPs at 0, 0.5, 1, 2, and 4 mg/kg for 8 weeks. The results suggested that Cu-NPs in diets increased the growth performance and reduced FCR with linear and quadratic model (P < 0.05). Also, common carp fed Cu-NPs showed increased carcass protein, lipid, and ash contents in a dose-dependent manner (P < 0.05). The Cu accumulation in the carcass, liver, muscle, and gills increased by Cu-NPs and showed the maximum at 4 mg Cu-NPs/kg (P < 0.05). No significant alterations were found in the blood variables due to Cu-NP supplementation except for the Hb, RBCs, total protein, albumin, and globulin levels which showed the highest level in 2 mg/kg (P < 0.05). IgM level, phagocytic, lysozyme, SOD, CAT, and GPX activities were boosted by Cu-NPs with decreased malondialdehyde (MDA) content (P < 0.05). Based on regression analysis, the requirement of dietary Cu-NPs for common carp was estimated to be 2.19 to 2.91 mg/kg diet.