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This study provides a comprehensive summary of the findings regarding the application and diagnostic efficacy of droplet digital PCR (ddPCR) in detecting viral and bacterial pathogens in aquaculture. Utilizing a systematic search of four databases up to 6 November 2023, we identified studies where ddPCR was deployed for pathogen detection in aquaculture settings, adhering to Preferred Reporting Items for Systematic Reviews and Meta-analysis of Diagnostic Test Accuracy guidelines. From the collected data, 16 studies retrieved, seven were included in a meta-analysis, encompassing 1121 biological samples from various fish species. The detection limits reported ranged markedly from 0.07 to 34 copies/μL. A direct comparison of the diagnostic performance between ddPCR with quantitative PCR (qPCR) proved challenging due to limited data, thus only a pooled sensitivity analysis was feasible. The results showed a pooled sensitivity of 0.750 (95% confidence interval [CI]: 0.487-0.944) for ddPCR, compared to 0.461 (95% CI: 0.294-0.632) for qPCR, with no statistically significant difference in sensitivity between the two methods (p = .5884). Notably, significant heterogeneity was observed among the studies (I 2  = 93%-97%, p < .01), with the year of publication significantly influencing this heterogeneity (p < .001), but not the country of origin (p = .49). No publication bias was detected, and the studies generally exhibited a low risk of bias according to QUADAS-C criteria. While ddPCR and qPCR showed comparable sensitivities in pathogen detection, ddPCR's capability to precisely quantify pathogens without the need for standard curves highlights its potential utility. This characteristic could significantly enhance the accuracy and reliability of pathogen detection in aquaculture., (© 2024 John Wiley & Sons Ltd.)

In the current study, the effects of dietary fulvic acid supplementation at levels of 0.5, 1 and 2% were examined in white-leg shrimp, Litopenaeus vannamei. A significant increase in the weight of the shrimp was observed in the group treated with 2% fulvic acid in comparison to the control group. This may have been associated with an increased digestive efficiency, with the food conversion ratio reducing from 2.4 to 1.9, and increased hepatopancreatic amylase, protease, and lipase enzyme activities. Enhanced activity of hemolymph superoxide dismutase was suggestive of an enhanced immune capacity, while hemolymph cell count increased by 16.4 and 13.6% in shrimp receiving diets supplemented with 1 and 2% fulvic acid, respectively. Additionally, the number of large granular cells increased by 37.3% and 40.8% relative to the control in these two groups. Furthermore, the lysozyme activity increased in shrimp receiving dietary supplementation of 1% and 2% fulvic acid by 16.7% and 24.7%, respectively. Phenol oxidase activity, which activates phagocytosis and encapsulation of invading pathogens, increased in all groups supplemented with fulvic acid, with the highest activity in the 1% fulvic acid group. Overall the present results suggest that fulvic acid is a promising feed additive for white-leg shrimp super-intensive culture., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Inc.)

Herbs and their by-products are important traditional medicines and food supplements; they provide numerous beneficial effects for animals. Consequently, probiotics are living cell organisms, nontoxic, and friendly microbes. Probiotics have numerous beneficial activities such as inhibition of pathogens, enhancement of the immune system, growth, disease resistance, improving water quality, reducing toxic effects, synthesis of vitamins, prevention of cancer, reduction of irritable bowel syndrome, and more positive responses in animals. Herbal and probiotic combinations have more active responses and produce new substances to enhance beneficial responses in animals. Herbal and probiotic mixture report is still limited applications for animals. However, the mechanisms by which they interact with the immune system and gut microbiota in animals are largely unclear. This review provides some information on the effect of herbal and probiotic blend on animals. This review discusses current research advancements to fulfill research gaps and promote effective and healthy animal production., (© 2024. The Author(s), under exclusive licence to Springer Nature B.V.)

The effects of long-term dietary supplementation with sandalwood (Santalum album L.) essential oil (SEO) was investigated on hemato-biochemical biomarkers, immune status, antioxidant capacity, and resistance against Staphylococcus aureus in Nile tilapia (Oreochromis niloticus). Five groups (with four replicates) of O. niloticus (12.60 ± 0.20 g) were fed diets supplemented with SEO at doses of 0, 0.5, 1.0, 2.0, and 4.0 mL/kg diet for 60 days. Results indicated a substantial increase in blood protein levels and lower serum cholesterol, cortisol, glucose, urea, creatinine levels and, transaminase activities of fish fed a 2.0-mL SEO/kg diet. Serum lysozyme activity, nitric oxide, complement-3 levels, and phagocytic activity were significantly improved in O. niloticus after 60 days of feeding SEO-supplemented diets. Dietary SEO at level of 2.0-mL SEO/kg diet increased the activities of SOD, CAT, and GPx, and decreased MDA levels in liver homogenate. In addition, dietary 2.0-mL SEO/kg diet significantly upregulated antioxidant genes expression (CAT, SOD, GPx, GST, and GSR) with downregulation of apoptotic genes (HSP70, TLR2, caspase-3, and PCNA) in the liver. Furthermore, SEO-enriched diets significantly down-regulated pro-inflammatory (TNF-α, IL-1β, and IL-8) and up-regulated anti-inflammatory cytokine genes (TFG-β and IL-10) in the spleen. Moreover, SEO fortification increased the relative percentage of survival against S. aureus challenge and regulated immune-antioxidant genes in the spleen after the challenge. Overall, the results revealed that long-term using SEO might strengthen the physiological performance, hepatic oxidant/antioxidant balance, innate immune response, and resistance of O. niloticus against bacterial infections., (© 2024. The Author(s), under exclusive licence to Springer Nature B.V.)

Recently, nano feed supplement research has great attention to improving healthy aquatic production and improving the aquatic environment. With the aims of the present study, chemical and green synthesized nanoparticles are characterized by various instrumentation analyses, namely UV-Vis spectrophotometry (UV-Vis), X-ray diffraction (XRD), Fourier transform infra-red (FTIR) spectroscopy, and scanning electron microscope (SEM). After characterization analysis of these nanoparticles utilized in aquatic animals, the composition ratio is as follows: controls (without ZnO-NPs (0 mg/L)), T1 (0.9 mg/L ZnO-NPs), T2 (1.9 mg/L ZnO-NPs), T3 (0.9 mg/L GZnO-NPs), T4 (1.9 mg/L GZnO-NPs). SEM investigation report demonstrates that the structure of the surface of green synthesized zinc oxide nanoparticles (GZnO-NPs) was conical shape and the size ranging was from 60 to 70 nm. Concerning hematological parameters, the quantity of hemoglobin increased in different doses of green zinc nanoparticles, but the values of MCV and MCH decreased somewhat. However, this decrease was the highest in the T2 group. Total protein and albumin decreased in T2 and triglyceride, cholesterol, glucose, cortisol, creatinine, and urea increased, while in T3 and T4 groups, changes in biochemical parameters were evaluated as positive. Mucosal and serum immunological parameters in the T2 group showed a significant decrease compared to other groups. In zinc nanoparticles, with increasing dose, oxidative damage is aggravated, so in the T2 group, a decrease in antioxidant enzymes and an increase in MDA were seen compared to other groups. In this regard, the concentration of liver enzymes AST and ALT increased in the T2 group compared with control and other groups. This can confirm liver damage in this dose compared with control and other groups. This research work suggests that green synthesized form of zinc nanoparticles in higher doses have less toxic effects in comparison to the chemical form of zinc nanoparticles and can act as suitable nutrient supplements in aquatic animals., (© 2023. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Colorectal cancer (CRC) is the second leading cause of cancer-related death, mostly due to metastatic disease and the fact that many patients already show signs of metastasis at the time of first diagnosis. Current CRC therapies negatively impact patients' quality of life and have little to no effect on combating the tumor once the dissemination has started. Danio rerio (zebrafish) is a popular animal model utilized in cancer research. One of its main advantages is the ease of xenograft transplantation due to the fact that zebrafish larvae lack the adaptative immune system, guaranteeing the impossibility of rejection. In this review, we have presented the many works that choose zebrafish xenograft as a tool for the study of CRC, highlighting the methods used as well as the promising new therapeutic molecules that have been identified due to this animal model., (© 2024. The Author(s).)

Oxygen nanobubble (NB-O 2 ) technology has been introduced to the aquaculture industry in recent years. This treatment usually results in a tremendously high level of dissolved oxygen (DO) in the water. However, little is known about the possible negative effects of hyperoxia due to NB-O 2 treatment (hyper-NB-O 2 ) on farmed fish. Here, we investigated i) the effect of short-term hyper-NB-O 2 exposure (single treatment) on the innate immunity in Nile tilapia, Oreochromis niloticus, and ii) the effect of long-term hyper-NB-O 2 exposure (26-day treatments) on survival, growth performance, gill histology, and gut microbiome in Nile tilapia. A single treatment with NB-O 2 for 10 min in 50 L of water resulted in 24.2 ± 0.04 mg/L DO (approximately 2-3 × 10 7 nanoscale oxygen bubbles/mL). This treatment did not result in differences in expression of several immune-related genes (e.g., TNF-α, LYZ and HPS70) in various tissues (e.g., gill, head kidney, and spleen) compared to the non-treated control. Over a 26-day period of exposure, no significant differences were observed in survival and growth performance of the fish, but minor histological changes were occasionally noted on the gills. Analysis of the gut microbiome revealed a significant increase in the genera Bosea, Exiguobacterium, Hyphomicrobium, and Singulisphaera in the group receiving NB-O 2 . Moreover, no signs of "gas bubble disease" were observed in the fish throughout the duration of the experiment. Overall, these results suggest that both short- and long-term hyper-NB-O 2 exposure appears to be benign and has no obvious adverse effects on fish., Competing Interests: Declaration of competing interest The authors declare no conflict of interest., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

The widespread use of produced metal oxide nanoparticles (NPs) has increased major concerns about their impact on human as well as aquatic animal health. The present study shows that exposure to different concentrations of zinc oxide (ZnO) NPs led to high accumulations of Zn ions in the metabolic organs of fish (liver and gills), resulting in severe oxidative stress in Carassius auratus . The goldfish ( C. auratus ) was chosen as an aquatic species for the evaluation of the potential toxicity of aqueous ZnO-NPs (Treatments of hemoglobin and neutrophils (0, 0.5, 1, and 1.5 mg L - 1 ) following 14 days of exposure. A range of histological and hematological factors were examined. Exposure to the NPs produced significant reduction of red blood cell and white blood cell counts, hematocrit) were found to produce no significant differences in lymphocyte, monocyte, and eosinophil counts; as well as the mean corpuscular hemoglobin concentrations index ( P  > 0.05). Moreover, the results revealed significant alterations in serum biochemical parameters, hepatic enzyme levels, and immune and antioxidant responses; except for total protein and superoxide dismutase (SOD) of C. auratus exposed to ZnO-NPs, particularly at the 1 and 1.5 mg L - 1 concentrations. Fish exposed to 1 and 1.5 mg L -1 ZnO-NPs displayed a significant reduction in alternative complement pathway activity, lysozyme, and total protein contents of mucus compared to those in the control group. The results showed that hepatic SOD and catalase, and gill catalase activity were significantly decreased, and their malondialdehyde levels increased at 1 and 1.5 mg L -1 ZnO-NPs compared to the control group ( P  < 0.05). Significant accumulations of ZnO-NPs were observed in the liver, kidney, and gill tissues of fish leading to severe histopathological alterations in these organs. These results suggest that water-borne ZnO-NPs can easily accumulate in metabolic organs and lead to oxidative stress and destructive effects on the physiological features of C. auratus .

The purpose of this study was to evaluate the effects of red yeast (Sporidiobolus pararoseus) produced from crude glycerol, as a by-product of the biodiesel production process, on the growth, innate immunity, expression of immune-related gene, and resistance of Nile tilapia against challenge with Streptococcus agalactiae. Fish were fed diets supplied with different concentrations of S. pararoseus dried cells at 0.0 (control; T1), 5.0 (T2), 10.0 (T3), and 20.0 (T4) g kg -1 diets for 90 days. The results showed that final body weight, weight gain, and average daily gain were significantly higher in fish fed T3 and T4 compared to the control group (p < 0.05). Likewise, significant (p < 0.05) increases in total carotenoid content, liver superoxide dismutase activity (SOD), and serum lysozyme and albumin were observed in Nile tilapia fed S. pararoseus, with the highest (p < 0.05) values displayed in fish fed the T4 diet. Moreover, up-regulation of IL-1β transcription in Nile tilapia spleen and liver was observed in fish feeding group T4. In a challenge test against S. agalactiae, the fish survival rate was significantly higher in fish fed red yeast compared to the control group (p < 0.05). The highest bactericidal activity found in the T4 group (p < 0.05). However, no significant differences were found in hematology, blood chemical, malondialdehyde (MDA), body chemical composition, organosomatic indices, and myeloperoxidase (p > 0.05) in all treatments. The present results suggested that red yeast S. pararoseus (20.0 g kg -1 ) can be used as a potential supplementation on growth, immune response, and disease resistance of Nile tilapia., (© 2022. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Medicinal plants are powerful antioxidants which can improve well-being and suppress oxidative stress caused by environmental toxins in aquatic animals. In this regard, the present research was designed to show the potential effects of psyllium (Plantago ovata) seed extract (PSE) on the growth, and immune responses of common carp Cyprinus carpio exposed to acute ammonia toxicity. To perform the study, fish were fed with diets containing 0 (T0), 0.25 (T1), 0.5 (T2), and 1% (T3) PSE for 60 days, and then exposed to ammonia (0.5 mg L -1 ) for 3 h. The findings showed that fish given the T1 diet outperformed the T3 and control groups in terms of ultimate weight, weight increase, and food conversion ratio. Additionally, the T1 group showed a significantly higher level of total protein and serum lysozyme activity than the other treatment groups. Moreover, the highest serum total immunoglobulin values were recorded in T1 and T2 groups. The results showed that PSE, especially at moderate levels, could successfully upregulate the transcription of immune-related genes (IFN-γ, Hsp70, TNF-ɑ, IL-1ß, IL-10, and IgE) compared to the control group after exposure to ammonia. Furthermore, improving ammonia-induced down regulations of antioxidant-related gene expressions (CYP1A, SOD, and GPX) was observed in fish fed with PSE-included diets compared to the control one. However, PSE-supplemented diets did not affect the mRNA expression level of CAT. Regarding tight junction-associated genes, the higher mRNA expression level of occludin was observed in the T1 group, whereas the downregulation of CLD3 gene occurred in all experimental groups. Conversely, significant upregulation of osmoregulation-associated gene (NKA) was recorded in all experimental groups compared to the control one. Therefore, the administration of PSE (0.25% of the diet) for 60 days is recommended to increase growth performance, improve health, and increase the resistance of common carp to oxidative stress caused by ammonia., (© 2022. The Author(s), under exclusive licence to Springer Nature B.V.)

Ornamental fish trade represents an important economic sector with an export turnover that reached approximately 5 billion US dollars in 2018. Despite its high economic importance, this sector does not receive much attention. Ornamental fish husbandry still faces many challenges and losses caused by transport stress and handling and outbreak of diseases are still to be improved. This review will provide insights on ornamental fish diseases along with the measures used to avoid or limit their onset. Moreover, this review will discuss the role of different natural and sustainable microbial feed additives, particularly probiotics, prebiotics, and synbiotics on the health, reduction in transport stress, growth, and reproduction of farmed ornamental fish. Most importantly, this review aims to fill the informational gaps existing in advanced and sustainable practices in the ornamental fish production.

The current study is designed to assay the efficacy of chlorogenic acid (ChA) in the diet on growth performance, digestive enzyme activity, serum immunological, biochemical, and antioxidant variables, and mucosal immune response as well as disease resistance of rainbow trout ( Oncorhynchus mykiss ) juveniles. Rainbow trout juveniles received diets supplemented with different inclusion levels of ChA (0 (ctrl), 200 (CA1), 400 (CA2), 600 (CA3), and 800 (CA4) mg kg -1 diet) for 60 days. According to the findings, fish from CA3 and CA4 groups demonstrated the best results considering the final weight (FW) and weight gain (WG) ( P < 0.05). Also, the group that received 600 mg kg -1 ChA-supplemented diet showed the lowest feed conversion ratio (FCR) and the highest specific growth rate (SGR) compared to other groups ( P < 0.05). Moreover, the minimum survival rate (SR) was only detected in the CA4 treatment ( P < 0.05). Regression analysis exhibited that rainbow trout growth indices were polynomially linked to dietary chlorogenic acid concentrations. In this regard, the optimal levels of chlorogenic acid according to growth parameters (FCR and SGR) were 0.71 and 0.62 gr kg -1 diet, respectively. The results exhibited superior performance of protease and amylase activities in CA2, CA3, and CA4 groups with the maximum amount in the group receiving 600 mg kg -1 ChA-enriched diet ( P < 0.05). Serum lysozyme (LYZ), immunoglobulin (Ig), and components 3 and 4 (C3 and C4) values of CA2, CA3, and CA4 groups were significantly higher than others with the highest amount in the CA3 group (P <0.05). Additionally, serum nitroblue tetrazolium (NBT) value in the CA3 and CA4 groups and myeloperoxidase (MPO) in the CA3 group were notably more than others ( P < 0.05). Moreover, the lowest aspartate aminotransferase (AST), alkaline phosphatase (ALP), alanine aminotransferase (ALT), and lactate dehydrogenase (LDH) and the highest total protein (TP) and globulin (GLO) values were observed in CA3 treatment ( P < 0.05). CA2 and CA3 groups demonstrated increased serum catalase (CAT) and decreased malondialdehyde (MDA) values compared to the control while the highest CAT and lowest MDA values were observed in CA3 treatment ( P < 0.05). Considering mucus immunity, the significantly maximum LYZ and protease values were demonstrated in CA2 and CA3 groups, and the highest ALP, Ig, and esterase values were demonstrated in the CA3 group. In comparison with the control, the mortality rates of the groups that received the ChA diets were remarkably ( P < 0.05) lower postchallenge with Y. ruckeri , and the highest survival and relative percentage of survival (RPS) ( P < 0.05) belonged to the CA3 group. Results obtained from the current study suggested ChA as a functional dietary additive to raise growth parameters, immune indices, antioxidant capacity, and resistance to disease in rainbow trout., Competing Interests: The authors declare that they have no conflict of interest., (Copyright © 2023 Hamed Ghafarifarsani et al.)

The purpose of this study was to evaluate the effect of Bacillus spp. mixture (Bacillus subtilis TISTR001, Bacillus megaterium TISTR067, and Bacillus licheniformis DF001) (1 × 10 6  CFU/g) on growth, immune parameters, immune-related gene expression, and resistance of Nile tilapia against Streptococcus agalactiae AAHM04. Fish were fed different concentrations of Bacillus spp. 0 (control; T1), 1 (T2), 3 (T3), and 5 (T4) g/kg diets for 120 days. The results showed that weight gain, average daily gain, specific growth rate, feed conversion ratio in T3 diet were significantly higher than the control group and other tested diets (p < 0.05). Immune parameters, such as myeloperoxidase and lysozyme, were significantly higher in the T3 and T4 diets compared to the control group (p < 0.05). Similarly, IL-1β and TNF-α gene expressions in the spleen of fish fed T2, T3, and T4 diets were significantly higher than the control group (p < 0.05). However, no significant differences in survival rate, hematology, blood chemical indices, malondialdehyde (MDA) levels, body chemical composition, and organosomatic indices (p > 0.05) were noticed in all treatments. No significant differences in survival rate after the challenge test with S. agalactiae AAHM04 were found in fish fed Bacillus spp. mixture diets, except for the T3 diet. These results suggest that Bacillus spp. mixture diet at 3 g/kg diet (T3) could improve growth, immune response, and disease resistance of Nile tilapia., (© 2021. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

This study was done to evaluate the effect of different quercetin levels on growth performance, immune responses, antioxidant status, serum biochemical factors, and high-temperature stress responses in common carp ( Cyprinus carpio ). A total number of 216 common carp with an average weight of 27.21 ± 53 g were divided into 12 tanks (four treatments × three replications) and fed 0 mg/kg quercetin (T0), 200 mg/kg quercetin (T1), 400 mg/kg quercetin (T2), and 600 mg/kg quercetin (T3) for 60 days. There were significant differences in growth performance, and the highest final body weight (FBW), weight gain (WG), specific growth rate (SGR), and feed intake (FI) were observed in T2 and T3 ( P < 0.05). Different quercetin levels significantly increased complement pathway activity (ACH50) and lysozyme activity both before and after heat stress ( P < 0.05). Catalase (CAT), glutathione peroxidase (GPx), and malondialdehyde (MDA) were significantly increased in fish exposed to heat stress, but fish fed with a supplemented diet with quercetin showed the lowest levels both before and after heat stress ( P < 0.05). Superoxide dismutase (SOD) levels were significantly enhanced in fish fed diets supplemented with quercetin in both phases ( P < 0.05). Different quercetin levels led to a significant decrease in alanine aminotransferase (ALT) and aspartate aminotransferase (AST) before and after the challenging test ( P < 0.05). Glucose and cortisol levels were significantly higher in the control group compared to the other treatments in both phases ( P < 0.05). The expression of glutathione peroxidase (GPx) and lysozyme was markedly upregulated in fish fed with quercetin-supplemented diets ( P < 0.05). No marked effects were observed for growth hormone (GR) and interleukin-8 (IL8) ( P > 0.05). In conclusion, dietary quercetin supplementations (400-600 mg/kg quercetin) improved growth performance, immunity, and antioxidant status and increased tolerance to heat stress., Competing Interests: The authors declare that they have no conflicts of interest., (Copyright © 2023 Kobra Armobin et al.)

The effects of dietary glycine supplementation, 0 (control), 5 (5 GL), and 10 (10 GL) g/kg, have been investigated on growth performance, hematological parameters, erythrocyte antioxidant capacity, humoral and mucosal immunity in common carp, Cyprinus carpio . After eight weeks feeding, the 5 GL treatment exhibited significant improvement in growth performance and feed efficacy, compared to the control treatment. Red blood cell (RBC) and white blood cell (WBC) counts, hemoglobin, hematocrit, neutrophil and monocyte counts/percentages, RBC reduced glutathione (GSH) content, and skin mucosal alkaline phosphatase, peroxidase, protease, and lysozyme activities were similar in the glycine-treated fish and significantly higher than the control treatment. Blood lymphocyte percentage decreased in the glycine-treated fish, but lymphocyte count increased, compared to the control fish. RBC glutathione reductase activities in the glycine-treated fish were similar and significantly lower than the control treatment. The highest plasma lysozyme and alternative complement activities were observed in GL treatment. The glycine-treated fish, particularly 5 GL, exhibited significant improvement in RBC osmotic fragility resistance. Dietary glycine had no significant effects on RBC glutathione peroxidase activity, plasma immunoglobulin, eosinophil percentage/count, and hematological indices. In conclusion, most of the benefits of dietary glycine supplementation may be mediated by increased glutathione synthesis and antioxidant power.

Carp is an important aquaculture species globally, and the production is expected to increase with the growing market demands. Despite that, disease outbreaks remain a major challenge, impeding the development of sustainable carp farming. Moreover, the application of antibiotics, a common prophylactic agent, can adversely impact public health and the environment. Therefore, polysaccharide has been recognized as a novel prophylactic agent in the health management of carp farming, as well as gaining consumers' confidence in carp farming products. In this review, the definition, sources, and main roles of polysaccharides in improving growth performance, stimulating the immune system, enhancing disease resistance, and alleviating abiotic stresses in carp farming are discussed and summarized. In addition, the use of polysaccharides in combination with other prophylactic agents to improve carp farming production is also highlighted. This review aims to highlight the roles of polysaccharides and provide valuable information on the benefits of polysaccharides in carp farming.

The identification and development of a new plant-based feed ingredient as an alternative protein source to FM have gained the interest of the aquafeed industrial players. Therefore, this study aimed to investigate the physical, biochemical, and bacteriological properties of dietary FWM and the impacts on the growth and reproductive performances of farmed female stinging catfish, H. fossilis broodstock. Five experimental diets were formulated with different FWM inclusion (0, 25, 50, 75, and 100%). Fatty acid profiles such as 4:0, 10:0, 20:0, 21:0, 22:0, 24:0, 20:1n9, 18:3n6, 20:3n6, 20:4n6, and 22:6n3 were found in higher levels in FWM compared to the water spinach meal (WM). Meanwhile, there were no significant differences in the physical properties of the FWM experimental diets (p > 0.05). Furthermore, the experimental feed with 0%, 25%, 50%, and 75% FWM were more palatable to the broodstock than 100% FWM. The number of total bacteria (TB) and lactic acid bacteria (LAB) in catfish diets exhibited a rising trend with an increase in FWM, while 50% of FWM-fed fish intestines had a significantly (p < 0.05) higher TB and LAB than other treatment groups. The growth, feed utilization, and reproductive variables of H. fossilis were significantly (p < 0.05) influenced by FWM inclusion at various levels. Moreover, the significantly (p < 0.05) highest oocytes weight, fertilization, egg ripeness, and ovipositor diameter were observed in the treatment of 50% FWM diet treatment group. In addition, the spawning response was 100% in all treatments except for the control group (66.67%). Significant differences (p < 0.05) were found in the hematological and serum biochemical indices in most treatment groups. In addition, the histological analysis of H. fossilis midintestinal tissue indicated that the fish fed with a 50% FWM diet had an unbroken epithelial barrier with more goblet cell arrangements and a well-organized villi structure and tunica muscularis compared to other treatment groups. These outcomes suggested that FWM at 50% inclusion is an adequate protein supplement for fish feed, resulting in better growth, reproductive performance, and health of H. fossilis broodstock development.

Colon cancer is one of the leading causes of death worldwide. In recent years, cannabinoids have been extensively studied for their potential anticancer effects and symptom management. Several in vitro studies reported anandamide's (AEA) ability to block cancer cell proliferation and migration, but evidence from in vivo studies is still lacking. Thus, in this study, the effects of AEA exposure in zebrafish embryos transplanted with HCT116 cells were evaluated. Totally, 48 hpf xenografts were exposed to 10 nM AEA, 10 nM AM251, one of the cannabinoid 1 receptor (CB1) antagonist/inverse agonists, and to AEA + AM251, to verify the specific effect of AEA treatment. AEA efficacy was evaluated by confocal microscopy, which demonstrated that these xenografts presented a smaller tumor size, reduced tumor angiogenesis, and lacked micrometastasis formation. To gain deeper evidence into AEA action, microscopic observations were completed by molecular analyses. RNA seq performed on zebrafish transcriptome reported the downregulation of genes involved in cell proliferation, angiogenesis, and the immune system. Conversely, HCT116 cell transcripts resulted not affected by AEA treatment. In vitro HCT116 culture, in fact, confirmed that AEA exposure did not affect cell proliferation and viability, thus suggesting that the reduced tumor size mainly depends on direct effects on the fish rather than on the transplanted cancer cells. AEA reduced cell proliferation and tumor angiogenesis, as suggested by socs3 and pcnp mRNAs and Vegfc protein levels, and exerted anti-inflammatory activity, as indicated by the reduction of il-11a, mhc1uba, and csf3b mRNA. Of note, are the results obtained in groups exposed to AM251, which presence nullifies AEA's beneficial effects. In conclusion, this study promotes the efficacy of AEA in personalized cancer therapy, as suggested by its ability to drive tumor growth and metastasis, and strongly supports the use of zebrafish xenograft as an emerging model platform for cancer studies., (© 2022. The Author(s).)

This study aimed to investigate the effects of mango peel powder (MGPP) on growth, innate immunity, and immune-antioxidant related gene expression of Nile tilapia reared under biofloc system. Three hundred Nile tilapia (average weight 14.78 ± 0.05 g) were distributed into 15 fiber tanks (300 L per tank) assigned to five treatments in triplication. Fish were fed basal diet containing different levels MGPP as follows: 0 (MGPP0: control), 6.25 (MGPP 6.25), 12.5 (MGPP 12.25), 25 (MGPP 25), and 50 (MGPP 50) g kg -1 diet for 8 weeks. Specific growth rate (SGR), weight gain (WG), final weight (FW), feed conversion ratio (FCR), skin mucus of lysozyme (SMLA), and peroxidase activities (SMPA), serum of lysozyme (SL) and peroxidase (SP) were measured every for weeks; while immune-antioxidant-related gene expressions were determined after 8 weeks post-feeding. The results indicated that MGPP 25 diet resulted in higher SGR, WG, FW, and FCR but no significant differences among treatments were noticed. In terms of immune responses, lysozyme and peroxidase activities in mucus and serum were significantly higher in MGPP 12.5 and MGPP 25 diets against the control. Similarly, significant up-regulation of IL-1 and IL-8 gene expressions was observed in fish fed MGPP 25 against the control. However, no significant differences in LBP, GSTa, GPX, and GSR among treatments were observed. Overall, dietary inclusion of MGPP 25 significantly enhanced immune response and immune related gene expressions but not growth performance and antioxidant gene expressions. The results implied that MGPP can be potentially used as an immunostimulants in Nile tilapia culture., Competing Interests: Declaration of competing interest The authors declare no conflict of interest., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

The study revealed the potential of fermented soybean meal (FSBM) as a fish meal (FM) replacement in African catfish (Clarias gariepinus) feed formulation. Five isonitrogenous diets (32% crude protein) were prepared with five different levels of FSBM as FM replacement, namely 0% FSBM (T1), 40% FSBM (T2), 50% FSBM (T3), 60% FSBM (T4), and 70% (T5). The experimental fish was given the formulated diet for eight consecutive weeks. At the end of the feeding trial, the fish were subjected to growth performance, blood parameters, blood chemical, liver histology, and gut microbiota assessment. The study findings demonstrated that the experimental fish that received the T2 diet exhibited significantly higher (p < 0.05) growth performance. Experimental fish that received diet T2 had significantly higher (p < 0.05) white blood cell (WBC) and significantly lower (p < 0.05) in terms of cholesterol (CHOL), albumin (ALB), globulin (GLOB), and total protein (TP). The replacement of FSBM to FM significantly affected liver morphology on the sinusoid, vacuole, nucleus, and erythrocytes. Gut microbiota composition analysis showed a significantly high abundance (p < 0.05) of Akkermansia muciniphila in the experimental fish that received the T2 diet. The gut microbiota indicates that the experimental fish is in a healthy condition. In conclusion, replacing 40% FSBM with FM in aquafeed could enhance C. gariepinus growth performance and health conditions.

The aquaculture industry is geared toward intensification and successfully meets half of the world's demand for fish protein. The intensive farming system exposes the animal to the risk of disease outbreaks, which has economic consequences. Antibiotics are commonly used for the health management of aquaculture species. However, this has several drawbacks, including the increase in antibiotic resistance in pathogenic bacteria and the entry of antibiotic residues into the human food chain, which is a public health and environmental concern. The potential of probiotics, prebiotics, synbiotics, and medicinal herbs as alternatives to antibiotics for the health management of aquaculture species has been investigated in numerous studies. This review discusses the potential use of combinations of probiotics and medicinal herbs as prophylactic agents in aquaculture, along with the definitions, sources, and modes of action. The positive aspects of combining probiotics and medicinal herbs on growth performance, the immune system, and disease resistance of aquaculture species are also highlighted. Overall, this review addresses the potential of combinations of probiotics and medicinal herbs as feed additives for aquaculture species and the key role of these feed additives in improving the welfare of aquaculture species., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Wei, Goh, Abdul Hamid, Abdul Kari, Wee and Van Doan.)

Huge amounts of non-edible by-products could be generated from fruit industrial processes. They consist mainly of peels together with low amounts of pulp and seeds. These by-products pose an environmental hazard due to soil, air, and water pollution. Moreover, treating these by-products is very expensive and under strict governmental regulations. Nevertheless, they are an excellent source of bioactive constituents, such as phenols, flavonoids, terpenes, and glucans. Based on their constituents, these by-products can significantly enhance the antioxidant defense, immune response, and modulation of gut microbiota and host resistance against various diseases. Therefore, sustainable valorization of fruits by-products can efficiently obtain value-added products that improve the well-being of organisms and reduce environmental stress, in addition to earning an additional industrial income. Since aquaculture is a vital economic sector, there is urgent to look for inexpensive natural food additives that improve health and maintain high nutritional quality for farming organisms without harming the environment and human health. Therefore, using fruit wastes as feed additives represents a striking alternative for fruitful aquaculture. In order to make use of these value-added products, it is a dire need to determine their biological effects on aquaculture organisms by understanding their mechanism of action. In this context, this review will holistically address a comprehensive focus on utilizing fruits by-products and their immunostimulant and antioxidative action., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Bioactive immunostimulants could be derived from different sources like plants, animals, microbes, algae, yeast, etc. Bioactive immunostimulants are the most significant role to enhance aquatic production, as well as the cost of this method, which is effective, non-toxic, and environment-friendly. These immunostimulants are supportive to increase the immune system, growth, antioxidant, anti-inflammatory, and disease resistance of aquatic animals' health and also improve aquatic animal feed. Diseases are mainly targeted to the immune system of aquatic organisms in such a way that different processes of bioactive immunostimulants progress are considered imperative techniques for the development of aquaculture production. Communicable infections are the main problem for aquaculture, while the mortality and morbidity connected with some outbreaks significantly limit the productivity of some sectors. Aquaculture is considered the mainly developing food production sector globally. Protein insists is an important issue in human nutrition. Aquaculture has been an exercise for thousands of years, and it has now surpassed capture fisheries as the most vital source of seafood in the world. Limited study reports are available to focal point on bioactive immunostimulants in aquaculture applications. This review report provides information on the nutritional administration of bioactive immunostimulants, their types, functions, and beneficial impacts on aquatic animals' health as well as for the feed quality development in the aquaculture industry. The scope of this review combined to afford various kinds of natural derived bioactive molecules utilization and their beneficial effects in aquaculture applications., Competing Interests: Declaration of competing interest Authors have no conflict of interest to declare for the publication of the present work., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Aeromonas hydrophila is a ubiquitous bacterium with various hosts that causes mass mortality in farm-raised fish species and significant economic losses. The current antibiotic treatment is ineffective in controlling this bacterium infection in aquaculture species. Therefore, an evaluation of potential phytobiotics is needed to find an alternative antimicrobial agent to reduce the over-reliance on antibiotics in aquaculture and safeguard public and environmental health. Furthermore, the rise in antibiotic resistance cases among pathogenic bacteria indicates an urgent need for new fish and shellfish health management solutions. In this context, phytobiotics applications in aquaculture can be defined as any medicinal plant-based antimicrobial agent used in fish and shellfish health management. This review will focus on the impacts of Motile Aeromonas Septicemia (MAS) due to A. hydrophila in aquaculture, the potential of phytobiotics in enhancing the tolerance of aquaculture species against MAS and the combination of phytobiotics with other antimicrobial and therapeutic agents against MAS., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Abdul Kari, Wee, Mohamad Sukri, Che Harun, Hanif Reduan, Irwan Khoo, Van Doan, Wen Goh and Seong Wei.)

Streptococcosis, particularly that caused by S. iniae and S. agalactiae , is a major re-emerging bacterial disease seriously affecting the global sustainability of aquaculture development. Despite a wide spread of the disease in aquaculture, few studies have been directed at assessing the in vitro antagonistic activity and in vivo efficacy of medicinal herbs and other plants against streptococcal agents. Most in vitro studies of plant extractives against S. iniae and S. agalactiae have found antibacterial activity, but essential oils, especially those containing eugenol, carvacrol or thymol, are more effective. Although essential oils have shown better anti-streptococcal activity in in vitro assays, in vivo bioassays require more attention. The extracts examined under in vivo conditions show moderate efficacy, increasing the survival rate of infected fish, probably through the enhancement of immunity before challenge bioassays. The available data, however, lack dosage optimization, toxicity and bioavailability assays of a specific plant or its bioactive compound in fish organs; hence, it is difficult to judge the validation of clinical efficacy for the prevention or treatment of fish streptococcosis. Despite the known bioactive compounds of many tested plants, few data are available on their mode of action towards streptococcal agents. This review addresses the efficacy of medicinal plants to fish streptococcosis and discusses the current gaps.

This study evaluated the effects of dietary supplementation of thyme (Thymus vulgaris) essential oil (TVO) on growth performance, digestive enzymes, biochemical parameters, hematological indices, liver enzymes, and pathogen resistance in common carp (Cyprinus carpio). Triplicate groups of fish (15.36 ± 0.10 g) were fed daily with diets supplemented with TVO at 0, 0.5, 1, and 2 percent for 60 days then challenged with Aeromonas hydrophila. The results determined that supplementation of thyme resulted in significantly higher final body weights (FBW) and lower feed conversion ratios (FCR). Furthermore, no mortality was observed in the thyme-supplemented treatments. Regression analysis showed that fish growth parameters were polynomially related to dietary TVO levels. The optimum dietary TVO level, based upon the varied growth parameters, was 1.344 to 1.436%. Digestive enzymes activity, including amylase and protease, significantly increased in fish fed the supplemented diets. The thyme-supplemented diets also significantly increased the biochemical parameters, including total protein, albumin, and acid phosphatase (ACP), compared to the control group. We also observed significant increases in hematological indices, including red blood cells (RBC), white blood cells (WBC), hematocrit (Hct), and hemoglobin (Hb) in common carp fed diets containing thyme oil ( P < 0.05). Liver enzymes activity including alanine aminotransferase (ALT), alkaline phosphatase (ALP), and aspartate aminotransferase (AST) was also reduced ( P < 0.05). Immune parameters, including total protein and total immunoglobulin (total Ig) levels, alternative complement pathway hemolytic (ACH 50 ), lysozyme, protease, and ALP in the skin mucus, and lysozyme, total Ig, and ACH 50 in the intestine were higher ( P < 0.05) in TVO-supplemented fish. Catalase (CAT), superoxide dismutase (SOD), glutathione reductase (GR), and glutathione peroxidase (GPx) in the liver were also elevated ( P < 0.05) in TVO administered groups. Lastly, thyme-supplementation resulted in higher survival rates after the A. hydrophila challenge compared to the control ( P < 0.05). In conclusion, dietary inclusion of thyme oil (1 and 2%) effectively improved fish growth, immune systems, and resistance to A. hydrophila., Competing Interests: The authors have no conflict of interest to declare for the publication of the work herein., (Copyright © 2022 Hamed Ghafarifarsani et al.)

Individual and combined efficacy of chitooligosaccharides (COS) and alginic acid (AA) at 1 g, 2 g, and 3 g per kg diet was assessed on growth and disease resistance in silver carp (Hypophthalmichthys molitrix) against Edwardsiella ictaluri. Growth parameters including specific growth rate (SGR), weight gain (WG), and feed conversion rate (FCR) were significant in fish fed 2 g and 3 g kg -1 of COS or AA, and fish fed combined COS + AA at 1, 2 and 3 kg -1 diet. In all groups, the survival rate (SR) was recorded 100%, except in group fed 2 g kg -1 AA diet. All the hematological and biochemical profiles significantly increased in groups fed 2 g and 3 g kg -1 of COS, AA, and COS + AA diets. Lipase and amylase enzyme activities and superoxide dismutase (SOD), malondialdehyde (MDA), glutathione peroxidase (GPx) antioxidant enzyme activities were significantly increased in fish fed 2 g and 3 g kg -1 of COS, AA, and COS + AA diet. Respiratory burst (RB), lysozyme (Lyz), reactive oxygen species (ROS) activities, and immunoglobuline (Ig) level were enhanced significantly in fish fed 2 g kg -1 of COS or COS + AA and all 3 g kg -1 diets, whereas nitric acid (NO) production and serum AP activity were improved in 2 g kg -1 COS + AA and 3 g kg -1 COS or COS + AA diets. Pro-inflammatory cytokine such as IL-8 mRNA transcriptions was significant in 2 g kg -1 COS + AA diet and all 3 g kg -1 diet. The IL-10 anti-inflammatory cytokine mRNA transcriptions were significant in 3 g kg -1 COS or COS + AA diets. This study was confirmed that H. molitrix fed with 3 g kg -1 COS or COS + AA diets were better activity when compared to other diet., Competing Interests: Declaration of competing interest All authors declare that they have no conflict of interest., (Crown Copyright © 2022. Published by Elsevier Ltd. All rights reserved.)

This study investigated the effects of dietary supplementation with anthocyanin extracted from black rice bran (AR) on the growth rate, immunological response, and expression of immune and antioxidant genes in Nile tilapia raised in an indoor biofloc system. A total of 300 Nile tilapia fingerlings (15.14 ± 0.032 g) were maintained in 150 L tanks and acclimatized for two weeks. Five experimental AR diets (0, 1, 2, 4, and 8 g kg -1 ) with various anthocyanin doses were used to feed the fish. We observed that the growth and feed utilization of fish fed with different dietary AR levels increased significantly after eight weeks (p < 0.05). In addition, the serum immunity of fish fed AR diets was much greater than that of those fed non-AR diets (p < 0.05). However, there were little or no difference in between fish fed AR enriched diets and the control AR-free diet (p > 0.05). After eight weeks, fish fed AR-supplemented diets had significantly higher mRNA transcript levels in immune (interleukin [IL]-1, IL-8, and liposaccharide-binding protein [LBP]) and antioxidant (glutathione transferase-alpha [GST-α] and glutathione reductase [GSR]) genes compared to control fish fed the AR-free diet, with the greatest enhancement of mRNA transcript levels (in the case of IL-8 by up to about 5.8-fold) in the 4 g kg -1  AR diet. These findings suggest that dietary inclusion of AR extract from black rice bran at 4-8 g kg -1 could function as a herbal immunostimulant to enhance growth performance, feed consumption, and immunity in Nile tilapia., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

The aquafeed industry continues to expand in response to the rapidly growing aquaculture sector. However, the identification of alternative protein sources in aquatic animal diets to replace conventional sources due to cost and sustainability issues remains a major challenge. Recently, insects have shown tremendous results as potential replacers of fishmeal in aquafeed. The present study aimed to review the utilization of insects in aquafeeds and their effects on aquatic animals' growth and feed utilization, immune response and disease resistance, and fish flesh quality and safety. While many insect species have been investigated in aquaculture, the black soldier fly ( Hermetia illucens ), and the mealworm ( Tenebrio molitor ) are the most studied and most promising insects to replace fishmeal in aquafeed. Generally, insect rearing conditions and biomass processing methods may affect the product's nutritional composition, digestibility, shelf life and required insect inclusion level by aquatic animals. Also, insect-recommended inclusion levels for aquatic animals vary depending on the insect species used, biomass processing method, and test organism. Overall, while an appropriate inclusion level of insects in aquafeed provides several nutritional and health benefits to aquatic animals, more studies are needed to establish optimum requirements levels for different aquaculture species at different stages of development and under different culture systems., Competing Interests: We declare that we have no financial and personal relationships with other people or organizations that can inappropriately influence our work, and there is no professional or other personal interest of any nature or kind in any product, service and/or company that could be construed as influencing the content of this paper., (© 2022 Chinese Association of Animal Science and Veterinary Medicine. Publishing services by Elsevier B.V. on behalf of KeAi Communications Co. Ltd.)

Caffeic acid is a phenolic metabolite known for its beneficial pharmaceutical effects and is suggested as a functional additive for aquaculture. In this study, the effects of caffeic acid on the growth performance, growth genes, digestive enzyme activity, and serum immune parameters of beluga (Huso huso) were investigated. For this purpose, 120 beluga juveniles (367.75 ± 21.32 g) were divided into 12 tanks and fed with caffeic acid at rates of 0 (T0, control), 1 (T1), 5 (T2), and 10 (T3) g/kg for 56 days. The final weight and weight gain of beluga were significantly higher in fish fed 5 (T2) and 10 (T3) g caffeic acid/kg than in the control group and 1 (T1) g caffeic acid/kg. The specific growth rate was significantly higher in beluga fed 10 g caffeic acid/kg than 0 and 1 g/kg. Compared with the control group, the amylase, lipase, and pepsin activities were significantly higher in T2 and T3. The relative expression of growth hormone and insulin-like growth factor significantly increased in T3 compared with the control group. The expression of lipoprotein lipase and nuclear factor interleukin 3 of beluga fed 5 and 10 g caffeic acid/kg was higher than the control group. The lysozyme activity, total immunoglobulin, and total protein in the serum of beluga significantly increased in fish fed with caffeic acid at different rates compared with the control group. Based on the finding, the results suggested that the inclusion of caffeic acid (5-10 g/kg) in the diets of beluga is recommended to enhance the growth performance, some digestive enzyme activity, and serum immune parameters., (© 2022 Wiley Periodicals LLC.)

The current perspective is a pioneer to assess the efficacy of Salvia officinalis leave powder (SOLP) on growth, intestinal enzymes, physiological and antioxidant status, immunological response, and gene expression of Common carp (Cyprinus carpio). We also looked into fish resistance after being challenged with Aeromonas sobria, a pathogenic zoonotic bacteria. Fish (N = 120) were fed four different experimental diets in triplicate for 8 weeks. The control diet (SOLP0 - without SOLP); meanwhile, the other three diets included SOLP of 2, 4, and 8 g kg -1 concentrations (SOLP2, SOLP4, and SOLP8), respectively. Findings demonstrated that fish fed SOLP4 and SOLP8 diets had better growth performance and improved digestion by noticeable enhancing lipase and amylase enzymes activity than other groups. Additionally, the antioxidant (superoxide dismutase and glutathione peroxidase) and immune activities (immunoglobulin M, nitric oxide, and antiprotease) clarified a significant increase (p < 0.05) in SOLP4 and SOLP8 groups. Enriched diets with SOLP4 and SOLP8 exhibited better expression of splenic genes (IL-1β, IL-6, IL-10, TLR-2, and SOD), intestinal genes (Slc26a6) and (PepT1 or Slc15a1), and muscular genes (IGF-1 and SOD), while MSTN was down-regulated. After 8 weeks of the experimental trial, C. carpio challenged by A. sobria exhibited the highest cumulative mortality (66.67%), while SOLP8-dietary intervention showed the best results in enhancing the fish resistance against A. sobria by lessening mortalities to 13.33% followed by SOLP4 diet (20%). The outcomes indicate that the expression of splenic, muscular, and intestinal genes confirm the efficacy of SOLP on enhancing growth, digestion, and immune-antioxidant status, and recommend the potential use of SOLP especially at 4 g kg -1 level as a valuable natural economic diet additive in C. carpio culture for sustaining aquaculture., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

The use of nano-sized materials is increasingly growing, while consequent health and environmental risks are still disputed. On the other hand, plant extracts have been reported to improve fish general health status and enhance antioxidant capacity. Thus, the present study was aimed to assess potential effects of Allium hirtifolium extract (AHE) to fortify antioxidant responses of Common carp (Cyprinus carpio) exposed to foodborne Zinc oxide nanoparticles (ZnO-NPs). Five hundred and forty fish were randomly allocated into 18 tanks and received six diets including a basal diet (as control), basal diet incorporated with either 13 mg/kg (ZnO-25) or 26 mg/kg (ZnO-50) of ZnO-NPs, 1.5% AHE (AHE-1.5), and similar concentrations of ZnO-NPs plus AHE (ZnO-25-AHE) and (ZnO-50-AHE) for a period of 30 days. Results revealed that blood indices, stress biomarkers (glucose and cortisol), and antioxidant parameters and genes in AHE-1.5 group were significantly modulated and improved when compared to other groups (P < 0.05). In AHE-enriched groups, serum and liver tissue antioxidative parameters were enhanced as reflected in a noticeable decrease in malondialdehyde value and an increase in catalase, superoxide dismutase, glutathione peroxidase, and glutathione reductase. However, current results showed that diets incorporated with ZnO-NPs elevated the stress parameters besides a significant reduction for most measured biochemical parameters and AHE supplementation ameliorated these effects in terms of improving antioxidant parameters. In ZnO-25-AHE, and ZnO-50-AHE, the values for expression of GPx were found significantly (P < 0.05) different from that of ZnO-25 and ZnO-50. On the contrary, SOD showed a non-significant difference (P > 0.05) among control, ZnO-25, and ZnO-50-AHE, also in-between ZnO-25 and ZnO-25-AHE. The present results indicate that AHE supplementation could trigger antioxidant responses both at tissue and molecular levels suggesting its outstanding protective effects against foodborne toxicity of ZnO-NPs in Common carp., (Copyright © 2022 Elsevier Inc. All rights reserved.)

Repeat breeding is a substantial problem in heifer and cow breeding leading to greater infertility for female dairy herds. The aim of present study was to investigate the impact of corpus luteum (CL) presence and category and the first gonadotropin-releasing hormone (GnRH) administration concurrent with exogenous progesterone (P4) treatment on the largest follicle (LF) size and pregnancy rate (PR) in repeat-breeder crossbred dairy heifers submitted to the fixed-time artificial insemination (AI) protocol. Heifers ( n = 243) were synchronised with (+GnRH) or without (-GnRH) first GnRH in the 7-day P4-GnRH-prostaglandin F2α-based programme. Each GnRH group was divided on presence of CL into two groups (+CL and -CL) in a 2 × 2 factorial arrangement. The PR was similar among -GnRH-CL (20.7%), -GnRH+CL (68.8%), +GnRH-CL (30.4%), and +GnRH+CL (68.3%) groups. However, presence of CL in heifers produced a 43.6% increase in PR compared to PR of heifers without CL (odds ratio = 6.550). Heifers bearing large-sized CL had greater large-sized LF on the day of fixed-time AI and PR. Plasma P4 concentration was positively related with CL diameter ( r = 0.845; p  < 0.001). The diameter of ovarian LF on the day of fixed-time AI was positively associated with P4 concentrations ( r = 0.512; p  < 0.001). We highlight that ovarian CL presence and category at the time of exogenous P4 treatment alters pre-ovulatory follicle size and PR but not initial GnRH treatment in repeat-breeder crossbred dairy heifers submitted to service with the 7-day fixed-time AI programme., Competing Interests: The authors declare no conflict of interest., (© 2022 Published by Elsevier Ltd.)

The present study was conducted to find the effects of dietary lactic acid (LA) supplementation on growth performance, hematological characteristics, humoral antioxidant and immunological factors, intestinal gene expression and bacteriological parameters in rainbow trout, Oncorhynchus mykiss. The fish (104 ± 0.90 g) were randomly distributed in twelve tanks (150 L water) as four treatments, receiving diets supplemented with 0, 5, 10, and 20 g/kg LA for 70 days. At the end of the feeding trial, no significant differences were observed in the fish growth performance and survival among the treatments. Blood/plasma red blood cell (5-20 g/kg LA), white blood cell (10 g/kg LA), hematocrit (5 and 10 g/kg LA), hemoglobin (5 and 10 g/kg LA), superoxide dismutase (10 g/kg LA), glutathione peroxidase (10 g/kg LA), total antioxidant capacity (10 g/kg LA), lysozyme (5-20 g/kg LA), and alternative complement activity (10 g/kg LA) significantly increased, as malondialdehyde (10 g/kg LA) significantly decreased in the LA-treated fish. Dietary LA supplementation induced no significant changes in the intestinal defensin gene expression, but significantly up-regulated the expression of toll-like receptor-3 (5-20 g/kg LA), Mx-9 (5-20 g/kg LA), and heat shock protein-70 (5 g/kg LA) genes; the highest expressions were observed at 5 g/kg LA supplementation. Dietary LA supplementation significantly increased total bacterial count (5 and 10 g/kg LA), Lactobacillus sp. (5-20 g/kg LA), and Bacteroides sp. (5-20 g/kg LA), but decreased Streptococcus iniae (5-20 g/kg LA) in the fish intestine; the highest Lactobacillus sp. And Bacteroides sp. Were observed in 10 and 5 g/kg LA supplementation, respectively. Overall, dietary LA supplementation, although has no significant effects on the fish growth performance, is beneficial to improve humoral antioxidant parameters, humoral and intestinal immunological parameters and intestinal microflora. According to the results, dietary 5-10 g/kg LA is recommended for the formulation of rainbow trout feed., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Organic acids are active substances required for improving the productivity and wellbeing of aquatic animals. Herein, the study investigated the effects of sodium propionate on growth performance, antioxidative and immune responses, and growth-related genes expression in beluga sturgeon (Huso huso). For eight weeks, fish fed sodium propionate at 0, 1.2, 2.5, and 5 g kg -1 . The final weight, weight gain, and SGR were substantially increased while FCR decreased by dietary sodium propionate at 2.5 and 5 g kg -1 (P < 0.05). The expression of Growth hormone (GH) and insulin-like growth factor 1 (IGF-1) was markedly upregulated (P < 0.05) by dietary sodium propionate in the gills and livers of beluga. The highest mRNA level of GH and IGF-1 has been observed in fish fed a 2.5 g sodium propionate/kg diet. The red blood cells count, and hemoglobin level were meaningfully increased (P < 0.05) by 2.5 and 5 g sodium propionate/kg diet compared with 0 and 1.2 g kg -1 levels. Further, the hematocrit level was increased (P < 0.05) by a dietary 5 g sodium propionate/kg diet. The total protein level and lysozyme activity were meaningfully increased (P < 0.05) by 2.5 and 5 g sodium propionate/kg diet compared with 0 and 1.2 g kg -1 levels. The highest superoxide dismutase was observed in fish fed 2.5 g sodium propionate/kg diet. Catalase activity was significantly higher in fish fed 5 g kg -1 than 1.2 g kg -1 . The glutathione peroxidase activity was markedly higher in fish fed 2.5, and 5 g kg -1 than fish fed control diet. The lowest malondialdehyde levels were observed in fish fed 1.2, and 2.5 g sodium propionate/kg diets. Moreover, the highest mucosal total protein, total immunoglobulin and lysozyme were recorded in fish fed 2.5, and 5 g sodium propionate/kg diets. The obtained results indicate that dietary sodium propionate is recommended at 2.5-5 g kg -1 to improve beluga sturgeon's growth performance, feed utilization, and wellbeing., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

This study aimed to evaluate the effects of rambutan peel powder (RP) on growth, skin mucosal and serum immunities, and immune-related gene expression of striped catfish (Pangasianodon hypophthalmus) reared in a biofloc system. Three hundred fingerlings (17.14 ± 0.12 g fish -1 ) were randomly selected and assigned to five treatments corresponding to five diets: 0 g kg -1 (control - RP0); 10 g kg -1  (RP10); 20 g kg -1  (RP20); 40 g kg -1  (RP40), and 80 g kg -1  (RP80) for 8 weeks. At weeks 4 and 8 post-feeding, growth, skin mucus, and serum immunity parameters were determined, whereas immune-related gene expressions were performed at the end of the feeding trial. Based on the results, skin mucus lysozyme (SML) and skin mucus peroxidase (SMP) were significantly higher in fish fed the RP diets compared to the control diet (P < 0.05). The highest SML and SMP levels were observed in fish fed RP40 diet, followed by RP20, RP80, RP10, and RP0. Fish-fed RP diets had higher serum lysozyme and serum peroxidase activities, with the highest value found in the RP40 diet (P < 0.05), followed by RP20, RP80, and RP10. Similarly, immune-related gene expressions (IFN2a, IFN2b, and MHCII) in the liver were significantly up-regulated in fish fed RP40. Up-regulation (P < 0.05) of IL-1, IFN2a, IFN2b, and MHCII genes was also observed in fish intestines, with the highest values observed in fish fed RP40 diet, followed by RP10, RP20, RP80, and RP0. Fish-fed diet RP diets also showed enhanced growth and FCR compared to the control, with the highest values observed in fish fed diet RP40. However, no significant differences in survival rates were found among diets. In conclusion, dietary inclusion of RP at 40 g kg -1 resulted in better growth performance, immune response, and immune related gene expressions of striped catfish (Pangasianodon hypophthalmus)., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

In the present study, the effects of dietary Halopithys incurva, a red macroalgae species, (0.25, 0.50, 1%) on whole-body serum and skin mucus immune system, antioxidant system and expression of various genes in zebrafish were investigated. At the end of the 8-week study, total protein, total immunoglobulin and lysozyme activities in whole-body serum and skin mucus increased in fish fed H. incurva (P < 0.05). While an increase was observed in superoxide dismutase (SOD), Catalase (CAT) and glutathione peroxidase (GPx) which are antioxidant enzyme activities in whole-body serum and skin mucus, a decrease in malondialdehyde (MDA) levels was detected (P < 0.05). All of the immune-related genes examined, such as Interleukin-1 beta (IL-1β), Tumor necrosis factor-alpha (TNF-α), Interferon-gamma (INF- γ), were upregulated by the addition of 0.5% H. incurva (P < 0.05). While SOD and GPx, which are antioxidant enzyme-related genes, were remarkably upregulated in macroalgae fed fish (P < 0.05), no change was observed in CAT gene expression (P > 0.05). Based on the results of this study, it is considered that the addition of 0.5% H. incurva to the diets of commercially farmed fish will increase their immune and antioxidant defences and may contribute to the aquaculture sector for more sustainability., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

The aquaculture sector is one of the main activities contributing to food security for humanity around the globe. However, aquatic animals are susceptible to several farming stressors involved in deteriorated growth performance, reduced productivity, and eventually high mortality rates. In some countries still, antibiotics and chemotherapies are comprehensively applied to control biotic stressors. Aside from the apparent benefits, the continuous usage of antibiotics develops bacterial resistance, deteriorates bacterial populations, and accumulates these compounds in the aquatic environment. Alternatively, environmentally friendly additives were used to avoid the direct and indirect impacts on the aquatic ecosystem and human health. In aquaculture, medicinal herbs and extracts are extensively used and approved for their growth-promoting, anti-inflammatory, and antioxidative properties. Herbal essential oils contain many bioactive components with powerful antibacterial, antioxidative, and immunostimulant potentials, suggesting their application for aquatic animals. Essential oils can be provided via diet and can benefit aquatic animals by improving their well-being and health status. The use of essential oils in aquafeed has been studied in a variety of aquatic animals to determine their beneficial roles and optimum doses. The outputs illustrated that herbal essential oils are exciting alternatives to antibiotics with prominent growth promotion, antioxidative, and immunostimulant roles. Herein, we reviewed the beneficial roles of essential oils in aquaculture. This review also aims to describe trends in herbal essential oils use, mainly in commercial fish species, and to analyze different factors that affect essential oils' efficacy on the growth performance, antioxidative, and immune responses of finfish species.

The aim of this study was to assess the anesthetic efficacy and biochemical effects of citronellal on rainbow trout, Oncorhynchus mykiss. The fish were exposed to 200-800 µl/L citronellal to find the anesthesia induction and recovery times. The deep anesthesia stage was reached within 117-613 s, using 800-200 µl/L citronellal, respectively, and all fish recovered within 240-420 s. To assess biochemical responses, the fish were exposed to 200, 400, 600, and 800 µl/L of citronellal and blood-sampled after deep anesthesia. The results showed that anesthesia led to significant elevations in blood erythrocytes, hematocrit, hemoglobin, mean corpuscular volume, plasma lactate, and lactate dehydrogenase; these parameters exhibited increasing trends as citronellal concentration increased. These results along with significantly higher plasma lysozyme activity, cortisol, and glucose levels in 200 µl/L treatment suggest that an increase in citronellal concentration significantly mitigates hypoxia/stress responses in the fish. Significant elevations in plasma alkaline phosphatase activity and malondialdehyde level were observed in the 200 µl/L treatment, which suggests induction of hemolysis and oxidative stress in this treatment. There was a tendency to higher ammonia levels along with the increase in citronellal concentration, which might be due to early ammonia accumulation because of lower opercular movement in the fish. Except for blood hematocrit and mean corpuscular volume, there were no significant differences between the 600 and 800 µl/L citronellal treatments. In conclusion, high concentrations of citronellal are more suitable for trout anesthesia and blood sampling than low concentrations. Based on the present study, 600-800 µl/L citronellal is recommended for trout anesthesia., (© 2021 Wiley Periodicals LLC.)

The present study aimed at assessing the singular and combined effects of water copper and polyvinyl chloride microplastic (MPVC) on intestinal copper accumulation, histopathological damage, and stress-/immune-related genes' expression in common carp, Cyprinus carpio. Four groups of fish were maintained in triplicate: control (kept in clean water), Cu (exposed to 0.25 mg/L of copper), MPVC (exposed to 0.5 mg/L of MPVC), and Cu-MPVC (exposed to 0.25 mg/L of copper + 0.5 mg/L of MPVC). After 14-day exposure, the fish of Cu and Cu-MPVC treatments exhibited significantly higher intestinal copper contents, compared to the fish of control and MPVC treatments. In this regard, the Cu-MPVC fish had significantly higher copper content than the Cu fish. Exposure to copper and/or MPVC significantly upregulated the intestinal heat shock protein 70 (hsp70), cytochrome P450 family 1 subfamily A member 1 (cyp1a1), lysozyme (lys), defensin (def), mucin 2 (muc2), and mucin 5 (muc5) expression. The highest expression of hsp70, cyp1a1, lys, and def was related to Cu-MPVC treatment; whereas, the highest expression of muc2 and muc5 was observed in Cu and MPVC treatments. Exposure to copper and/or MPVC induced intestinal damage, which Cu-MPVC fish exhibited the highest severity. The present study revealed that exposure to copper and/or MPVC causes intestinal histopathological damage and upregulation in stress- and immune-related genes' expression. The most serious effects were observed in Cu-MPVC treatment that might be due to additive effects of copper and MPVC and/or higher copper accumulation in this treatment., (© 2021 Wiley Periodicals LLC.)

Dietary Lactobacillus acidophilus ATCC 4356 was used to relieve the impacts of aflatoxin B 1 toxicity on the performances of Liza ramada. The control diet was without any additives, while the second and third diets were supplemented with aflatoxin B 1 at 0.5 and 1 mg/kg. The fourth diet was supplemented with Lb. acidophilus ATCC 4356 at 1 × 10 6  CFU/mL per kg diet, while the fifth with aflatoxin B 1 at 1 mg/kg and Lb. acidophilus ATCC 4356 at 1 × 10 6  CFU/mL per kg diet. The growth performance markedly increased (p < 0.05) in L. ramada fed Lb. acidophilus ATCC 4356, while aflatoxin B 1 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 B 1 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 B 1 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 B 1 at 1 mg/kg groups while decreased in aflatoxin B 1 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 B 1 at 0.5 and 1 mg/kg groups. The highest levels of blood glucose and cortisol were seen in fish contaminated with aflatoxin B 1 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 B 1 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 B 1 at 1 mg/kg diets while increased in fish contaminated with aflatoxin B 1 at 0.5 and 1 mg/kg (p < 0.05). The control group had lower malondialdehyde levels than the aflatoxin B 1 at 1 mg/kg group and higher than the Lb. acidophilus ATCC 4356 with or without aflatoxin B 1 toxicity (p < 0.05). Histopathological examination revealed impaired intestines and livers in fish contaminated with aflatoxin B 1 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., (© 2021. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

The combined effects of copper and polyvinyl chloride (PVC) microparticles were investigated on the metal accumulation, histopathological biomarkers, and targeted transcriptomics in Cyprinus carpio liver. The fish were exposed to 0.25 mg/L copper and/or 0.5 mg/L PVC microparticles over a 14-d period. The results showed that hepatic copper accumulation is facilitated by the PVC microparticles presence in water. All treatments induced significant hepatic stress and inflammation; however, the transcriptional responses involving in detoxification pathways and apoptotic mechanisms were mixed and often down-regulated in the fish exposed to copper and/or PVC microparticles. Exposure to copper and/or PVC microparticles induced hypermeia, leukocyte infiltration and increase in melanomacrophage centers number and area. Generally, the severity of the lesions was in the following order: PVC microparticles < copper < copper+ PVC microparticles. In conclusion, PVC MPs act as a copper vector, facilitating accumulation of copper in the fish liver and increasing the tissue damage., (Copyright © 2022 Elsevier Ltd. All rights reserved.)

Nowadays, industrial poultry producers are more focused on the safety of their products, especially contaminants from feedstuffs such as mycotoxin and pesticides. The residue from animal production using antibiotic growth promoters (AGPs) may cause some problems with antimicrobial resistance in human and animals. Red yeast ( Sporidiobolus pararoseus ) has a cell wall consisting of β-glucan and mannan-oligosaccharides and pigments from carotenoids that may be suitable for use as a substitute for AGPs. The objective was to evaluate the effects of red yeast in laying hen diets on productive performance, egg quality, and duodenal health. A total of 22-week-old laying hens ( n = 480) were divided into five groups: control diet (CON), AGP at 4.5 g/kg and red yeast supplementation at 1.0 (RY1.0), 2.0 (RY2.0) and 4.0 g/kg (RY4.0) of diet. The results show that the AGP, RY2.0, and RY4.0 groups had significantly higher final body weight compared with the other groups ( p < 0.001). The red yeast supplementation improved the egg shape index ( p = 0.025), Haugh unit ( p < 0.001), and yolk color ( p = 0.037), and decreased yolk cholesterol ( p < 0.001). Diet with red yeast supplementation improved villus height to crypt depth ratio and crypt cell proliferations. In conclusion, red yeast supplementation at 2.0 g/kg of diet can substitute AGP in layer diet.

The current study addressed to investigate the effect of lycopene (LYC) on blood physiology, digestive-antioxidant enzyme activity, specific-nonspecific immune response, and inflammatory gene transcriptional regulation (cytokines, heat shock proteins, vitellogenins) in spotted snakehead (Channa punctata) against Pseudomonas aeruginosa. In unchallenged and challenged fish treated with 200 mg LYC enriched diet the growth performance and digestive-antioxidant enzymes increased after 30 days, whereas with inclusion of 100 or 400 mg LYC in the diets, the increase manifested on or after 45 days. No mortality in fish treated with any LYC diet against P. aeruginosa was revealed. In the unchallenged and challenged fish the phagocytic (PC) activity in head kidney (HK) and spleen were significantly enhanced when fed the control diet or other LYC diets, whereas the respiratory burst (RB) activity and nitric oxide (NO) production significantly increased when fed the 200 mg diet for 45 and 60 days. Similarly, the lysozyme (Lyz) activity in the HK and spleen, and total Ig content in serum were significantly higher in both groups fed the 200 mg LYC diet for 15, 45, and 60 days. Heat shock protein (Hsp 70) was significantly improved in the uninfected group fed the 200 mg LYC diet for 45 and 60 days, but Hsp27 did not significantly change among the experimental groups at any time points. TNF-α and IL-6 mRNA pro-inflammatory cytokine expression significantly increased in both groups fed the 200 mg LYC diet after 45 and 60 days, while the IL-12 mRNA expression was moderate in both groups fed the same diet for 60 days. The IL-10 did not significant mRNA expression between groups at any sampling. The iNOS and NF-κB mRNA expression was pointedly high in both groups fed the 200 mg LYC diet on day 45 and 60. Vitellogenin A (VgA) mRNA was significantly higher in the uninfected fish fed the 100 and 200 mg LYC diets for 45 and 60 days, but VgB did not reveal significant difference between the treatment groups at any time points. The present results suggest that supplementation of LYC at 200 mg significantly modulate the blood physiology, digestive-antioxidant enzymes, specific-nonspecific immune parameters, and cytokines, Hsp, and vitellogenins in spotted snakehead against P. aeruginosa., (Crown Copyright © 2021. Published by Elsevier Ltd. All rights reserved.)