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Aeromonas hydrophila, a ubiquitous, free-living, Gram-negative bacterium, is prevalent in aquatic habitats with cosmopolitan distribution; it is an opportunistic pathogen that has resulted in heavy mortalities in farmed and feral fishes. The traditional application of antibiotics and chemotherapy has been characterized by partial success in the management of diseases like motile aeromonad septicemia (MAS) and aeromonad-associated diseases like epizootic ulcerative syndrome (EUS). Application of antibiotics and chemotherapeutic drugs are necessary in the disease management though this practice has triggered the emergence of drug resistant strains in pathogens. Further resistance may be transferred to other related or unrelated bacteria; therefore, it is necessary to develop and screen new chemicals. Disease prevention by means of vaccination and immuno-stimulation of fish in aquaculture has been particularly successful against several bacterial diseases. For example, mono and multivalent vaccines have been developed against several bacterial diseases in fish. However, when new diseases and pathogens emerge from time to time, it would be difficult to develop such proactive strategies quickly. Recently, probiotics are widely used in aquaculture since they produce bacteriocins and other chemical compounds inhibiting the growth of pathogenic bacteria. Another emerging trend is medicinal plant research, which has increased the world over since herbs used in traditional medicine have little side effects are easily biodegradable and abundantly available in farm areas free of cost. Some herbals that wield potent antibacterial activity against shrimp and fish bacterial pathogens have a crucial role in disease management. Indeed, application of probiotics and herbals in aquaculture may also reduce cost of disease management by obviating the expenses incurred by the use of antibiotics, chemicals, and vaccinations in the future. [ABSTRACT FROM AUTHOR]

The chronomorphological events during the development of the egg of the freshwater caridean prawn, Macrobrachium nobilii, were followed from spawning to hatching. The female is receptive only for a 30-minute period after the premating moult. After mating, spawning ensued within 9 ± 3 hours and was completed within 15-20 seconds. Unmated females also spawned but the eggs did not survive. The rate of egg development increased 2·5x for a temperature rise of 10°C. Hatching was synchronised under in vitro conditions indicating uniform development of a clutch. [ABSTRACT FROM AUTHOR]

The current study was designed to examine the impacts of dietary mannan-oligosaccharides (MOS) on growth, hemato-biochemical changes, digestive-antioxidant enzyme activity, immune response, and disease resistance of milkfish (Chanos chanos) fed diets contained MOS i.e. 1g, 2g, and 3g MOS. The growth parameters were significantly influence in milkfish fed all MOS diets, whereas the feed conversion ratio (FCR) and protein efficiency ratio (PER) were significantly influence with 2g or 3g MOS diets. The total protein (TP), globulin (GB), and glucose (GLU) levels, amylase, protease, liver enzymes were found significantly high in fish fed 2g or 3g MOS diets; but, lipase, trypsin, and alkaline phosphatase (ALP) enzymes were increased significantly at 3g MOS diet. All MOS inclusion levels were significantly increased total and Lactobacillus intestinal microflora population. The oxidative enzymes activity as superoxide desmutase (SOD) and catalyze (CAT) were progressively increased with all MOS supplementation diet, but the glutathione peroxidase (GPx) and lactate dehydrogenase (LDH) content were found significantly high in fish fed 2g or 3g MOS diets. Similarly, the reduced glutathione (GSH) and glutathione reductase (GR) contents were observed significantly high level in fish fed 3g MOS diet. The phagocytic (PC) and lysozyme (LYZ) activities were found gradually increase in fish fed increasing level of MOS diets, while the respiratory burst (RB) and malondialdehyde (MDA) activities were seen significant in fish fed 2g and 3g MOS diets. The current research work confirmed that C. chanos fed diets contained 3g kg -1 MOS recorded better growth performance, digestive-antioxidant, immune response, and disease resistance., Competing Interests: Declaration of competing interest All authors declare that they have no conflict of interest., (Crown Copyright © 2023. Published by Elsevier Ltd. All rights reserved.)

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.)

The effect of four level of Astragalus polysaccharides (APs) supplementation diets, (CD: control diet and three experiment diet (E), EA: 100 mg kg -1 APs; EB: 200 mg kg-1 APs; EC: 300 mg kg -1 APs) on growth, changes in haemato-biochemical parameters and metabolic-digestive enzymes, enhancement of antioxidant activity, innate-adaptive immune response, and cytokine gene expression were studied in catla (Catla catla) against Edwardsiella tarda. The healthy and challenged groups fed the CD displayed no mortality, while fish fed EA or EC revealed 10% mortality, but the mortality was only 5% in diet EB. Fish fed diet EB and EC revealed significantly better growth rates and high RBC count during the experimental period. Albumin and globulin levels were significant improved when fish were fed the diet EB and EC from weeks 6-8. The superoxide dismutase (SOD) was significant ameliorated by EB feeding from weeks 4-8. In contrast, serum myeloperoxidase (MPO), catalase (CAT), malondialdehyde (MDA)/lipid peroxidation (LPO), glutathione peroxidase (GPx), respiratory burst activity (RBA), bactericidal action (BCA), serum lysozyme activity (SLA), nitric oxide synthase (NOS), head kidney leukocytes response proliferation (HKLP), hemolytic action (HLA), hydrogen peroxides (H 2 O 2 ), and immunoglobulin (Ig) were significantly improved from week 6-8. Groups fed the APs enriched diets had significant ameliorated interleukin (IL)-1β and interferon (IFN)-γ mRNA expression after 6 and 8 weeks of feeding. However, IL-10 and major histocompatibility complex (MHC)-1 mRNA expressions were significant enhanced in catla fed all APs diets on week 8. APs enriched diets revealed significant improved tumor necrosis factor (TNF)-α and TNF receptor-associated factor-6 (TRAF6) mRNA expression on week 4, but toll-like receptor-2 (TLR2) and TLR4 mRNA expression were significant enhanced by diet EB and EC after weeks 6 and 8. Similarly, the lysozyme (Lyz)-C and Lyz-G mRNA levels in the head kidney (HK) increased by APs feeding on weeks 6 and 8, whereas the EB diet, the expression of nucleotide binding oligomerization domain-1 (NOD1) was significantly improved on weeks 6 and 8, but NOD2 mRNA expression was only significant enhanced after 8 weeks of diet EB. By feeding healthy catla and E. tarda challenged fish fed diet EB, resulted in significantly increased growth, haemato-biochemical indices, metabolic-digestive enzymes, antioxidant activities, innate-adaptive immune responses, and cytokine gene expression mainly between 6 and 8 weeks., (Crown Copyright © 2022. Published by Elsevier Ltd. All rights reserved.)

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.)

Effect of bamboo vinegar powder (BVP) on growth, immunity, disease resistance, and immune-related gene expressions in juvenile Asian sea bass (barramundi), Lates calcarifer against Vibrio anguillarum was investigated. V. anguillarum infected fish fed by 2g BVP kg -1 diet exhibited significant growth, albumin (AB), serum total protein (TP), and globulin (GB) levels. Similarly, enhanced lysozyme (LZM), phagocytic (PC), anti-protease (AP), respiratory burst (RB), bactericidal (BC) activities and total immunoglobulin (Ig) levels were observed in fish fed 2g BVP kg -1 . In addition, use of 2g BVP kg -1 in diet modulated several immune related gene expressions against Vibrio disease. This study exhibited a positive effect of dietary 2g BVP kg -1 diet on hemato-biochemical and immunological responses, which enhance the immunocompetence and health status of L. calcarifer against V. anguillarum infection., (Crown Copyright © 2021. Published by Elsevier Ltd. All rights reserved.)

Effect of dietary with 100, 200, and 300 mg kg -1 glycyrrhizic acid (GA) on growth enhancer, blood physiology, digestive-antioxidant enzyme ability, innate-adaptive defense, and inflammatory cytokines induction was studied in silver carp, Hypophthalmichthys molitrix against vibriosis caused by Vibrio alginolyticus. Significant weight gain (WG), specific growth rate (SGR), and 100% survival rate (SR) was attained non-infected health (NiH) fish fed in control or all GA diets on 30, 45, and 60 days. Both NiH and V. alginolyticus challenged (VaC) fish treated with 200 mg GA diet significantly (P < 0.05) exhibited an enhancement in leucocytes value on 30, 45, and 60 days. Albumin (AB) or total proteins (TP) levels were significantly (P < 0.05) better in both groups fed 200 GA on 45 and 60 days. Malondialdehyde (MDA) and superoxide dismutase (SOD) activities were also substantial (P < 0.05) in both groups fed 200 mg GA on days 30, 45, and 60; whereas glutathione peroxidase (GPx) and catalase (CAT) activities were significantly (P < 0.05) better in both groups received 200 mg GA on days 45 and 60. Phagocytic (PC) and lysozyme (Lyz) activities significantly enhanced in both groups fed 200 or 300 mg GA on 45 and 60 days. Respiratory burst (RB), reactive oxygen species (ROS) and immunoglobulin (Ig) production significantly (P < 0.05) increased in both groups administered 200 or 300 mg GA. Growth hormone (GH) mRNA was up regulated in 200 mg GA trial on 45 days and in 200 or 300 mg GA treatments on 60 days. The IL-8 cytokine mRNA expression was up-regulated in both groups 200 and 300 mg GA on days 45 and 60, whereas TNF-α mRNA expression was increased in 200 mg GA. In addition, IL-10 cytokine mRNA expression was up regulated in 200 mg GA on 45 days whereas it was increased in both 200 mg and 300 mg GA trial on 60 days. The present study revealed that feeding fish 200 mg GA per kg diet demonstrated a better growth, digestive-antioxidant activity, innate-adaptive defense, and inflammatory cytokines induction than lower or higher dosage of GA in H. molitrix against V. alginolyticus., (Crown Copyright © 2021. Published by Elsevier Ltd. All rights reserved.)

The effects of dietary k-Carrageenan (k-CGN) at 10, 20, and 30 g kg -1 on growth rate, hemato-biochemical indices, innate-adaptive parameters and modification of pro- and/or anti-inflammatory cytokines and chemokines pathway in cobia, Rachycentron canadum against Lactococcus garvieae is reported. The weight gain (WG) increased substantially (P < 0.05) in all k-CGN treated groups; the specific growth rate (SGR) was significant in healthy uninfected normal (HuN) and L. garvieae challenged (LaC) groups fed with 20 g kg -1 k-CGN diet on 45 and 60 days. The white blood cell (WBC) counts, total protein (TP) level, total anti-oxidant (T-AOC), catalase (CAT), and glutathione (GSH) activities increased significantly when fed with 20 g and 30 g kg -1 k-CG diets on 45th and 60th day. The immunological parameters such as phagocytic (PC) index and the activity of phagocytic (PC), respiratory burst (RB), superoxide dismutase (SOD), alternate complement pathway (ACH 50 ), and lysozyme (LZM) were significantly enhanced with all k-CG diets in 45 and 60 days of treatment. No cumulative mortality (CM) in HuN group fed by control or any k-CGN diets. CM was 5% in LaC group fed with 20 g kg -1 k-CGN diet whereas in LaC groups fed with 10 g and 30 g kg -1 k-CGN diets the CM was 10%. The interleukin 1 beta (IL-1β) and tumor necrosis factor alpha (TNFα) pro-inflammatory cytokines mRNA transcripts were one-fold high (P < 0.05) in both HuN and LaC group fed all k-CGN enriched diets on 45 and 60 days. Similarly, IL-18 and TLR2 mRNA was one-fold high expression in both groups fed the 20 g and 30 g kg -1 k-CGN enriched diets on 45 or 60 days. Interferon gamma (IFNγ) and interferon regulatory factor 3/7 (IRF3/IRF7) mRNA transcripts did not change with any diet. IL-6, IL-10, and IL-11 mRNA were one-fold high expressions in both groups fed the 20 g and 30 g kg -1 k-CGN enriched diets on 45 and 60 days. However, the expression of CC1, CC3, and CCR9 pro-inflammatory chemokines mRNA did not vary with any control or k-CGN enriched diets. The results indicate that diet enriched with k-CGN at 20 g kg -1 significantly influences the growth, antioxidant and innate-adaptive immune performance, and pro-anti-inflammatory cytokines and chemokines regulation in cobia against L. garvieae., (Crown Copyright © 2021. Published by Elsevier Ltd. All rights reserved.)

The effect of cinnamaldehyde (CM) enriched diet on immunity and cytokine gene expression in Channa striatus against Aphanomyces invadans is reported. C. striatus was uniformly divided into eight groups (n = 25 fish each) and fed with formulated diets with 0, 5, 10, and 15 mg kg -1  CM enriched diet. In healthy and infected groups fed with 5 mg kg -1 diet the leukocytes count increased significantly after 4th week; with 10 mg kg -1  CM diet the increase manifested after 6th week, but with 15 mg kg -1 not even after 8th week. In both groups, 5 mg kg -1  CM diet resulted in a significant increase in the serum total protein, albumin, and globulin levels after 4th week, whereas with other diets this effect was observed only after 6th week. Similarly, with any enriched diet the lysozyme activity increased significantly, but with 15 mg kg -1  CM diet only after 6th week. In both groups the complement activity and lymphocyte production increased significantly when fed with 5 mg kg -1  CM diet after 4th week while with other enriched diets only after 6th week. The phagocytic activity increased significantly in both groups fed with 5 mg kg -1  CM diet after 6th week, whereas the SOD activity increased after 4th week. The IgM production increased significantly in both groups fed with 5 mg kg -1  CM diet after 2nd week, while with 5 and 10 mg kg -1  CM diet after 4th week. In both groups, the expression of CXCR3α was significant on 4th week when fed with 10 mg kg -1  CM diet, while in the healthy group fed with 15 mg kg -1  CM diet the expression manifested earlier than 4th week. However, when fed with 10 and 15 mg kg -1  CM diets the increase was observed on 6th week; whereas, the expression of MHC-I reached the maximum on 6th week with any enriched diet. The results indicate that in C. striatus the innate immunity and expression of cytokine and immune related genes were significantly modulated when fed with 5 mg kg -1  CM diet on 4th week against A. invadans., (Crown Copyright © 2021. Published by Elsevier Ltd. All rights reserved.)

This study reports the effect of ulvan enriched diet on the influence of growth, changes in hemato-biochemical indices, improvement of antioxidant system, enhancement of innate-adaptive immunity and modification of immuno-antioxidant genes expression in Labeo rohita against Flavobacterium columnaris. The weight gain (WG) was significantly high (P > 0.05) in unchallenged normal and challenged fish fed with diets enriched with 25 and 50 mg kg -1 ulvan; the FCR was better (P > 0.05) when fed with 50 mg kg -1 enriched diet. In normal fish fed with or without ulvan supplementation was noted 100% survival rate (SR). In both groups, the red blood cell (RBC) and while blood cell (WBC) counts increased significantly (P > 0.05) when fed with 50 mg kg -1 ulvan diet whereas the hemoglobin (Hb) level increased significantly on being fed with 25 and 50 mg kg -1 ulvan diets. The SOD activity was enhanced significantly in both groups fed with any dose of ulvan diets whereas the MDA and GPx activity increased only with 25 and 50 mg kg -1 ulvan diets. The phagocytic (PC) activity significantly increased with any enriched diet and control diet groups while the respiratory burst (RB) activity increased only with 50 mg kg -1 ulvan diet. The alternate complement pathway (ACP), activity of lysozyme (Lyz), and immunoglobuline M (IgM) were better in both groups fed with 50 mg kg -1 ulvan diet. The SOD and GPx antioxidant gene expression were significantly high in both groups fed with any ulvan diet while the Nrf2 gene expression was high with 50 mg kg -1 ulvan diet. The IL-1β, TNFα, hepcidin, Lyz, and IgM cytokines or proteins mRNA expression were significant in both groups fed with all ulvan supplement diet whereas the β-2M expression was significant only with 50 mg kg -1 ulvan diet. The present research indicates that both L. rohita groups fed with 50 mg kg -1 ulvan diet significantly improved growth, antioxidant system, immune defense system, and immuno-antioxidant related gene expression against F. columnaris., (Crown Copyright © 2021. Published by Elsevier Ltd. All rights reserved.)

The effect of Agaricus bisporus polysaccharides (ABPs) supplemented diet on growth rate, antioxidant capacity, innate-adaptive immune response, proinflammatory and antiinflammatory genes expression in Ctenopharyngodon idella against Aeromonas hydrophila is reported. In both normal and challenged groups fed with 1.0 and 1.5 mg kg -1 ABPs diets resulted in a significant weight gain and feed intake. The survival was 100% in normal fish fed without or with any ABPs diet; the challenged fish fed with 1.0 mg kg -1 ABPs diet had 98.6% survival. The RBC and WBC counts, Hb, and Hct levels were significant in both normal and challenged groups fed with 1.0 and 1.5 mg kg -1 ABPs diets. A significant increase in total protein and albumin level was observed in both groups fed with 1.0 and 1.5 mg kg -1 ABPs diets. Significant increase in GPx, ROS, GR, GSH, PC, and MnSOD activity was observed in HK of both groups fed with 1.0 and 1.5 mg kg -1 ABPs diets; similarly both groups when fed with the same ABPs diets showed significant Lz, C3, and C4 activity. However, both groups fed with 1.0 mg kg -1 ABPs diet showed significant β-defensin, LEAP-2A, IL-6, and NF-κB P65 mRNA expression. Similarly, IFN-γ2, IL-10, and TNFα mRNA expressions were significant in both groups fed with 1.0 mg kg -1 ABPs diet. The results indicate that both normal and challenged C. idella fed with a 1.0 mg kg -1 ABPs diet had better growth, antioxidant status, immune response, and pro-anti-inflammatory gene modulation against A. hydrophila., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

This study evaluates the effects of dietary inclusion of grape pomace flour (GPF) on growth, antioxidant, anti-inflammatory, innate-adaptive immunity, and immune genes expression in Labeo rohita against Flavobacterium columnaris. In both normal and challenged fish the growth rate, hematology and biochemical parameters significantly increased when fed with 200 and 300 mg GPF enriched diets; similarly the activities of antioxidants and innate-adaptive immune parameters, such as malondialdehyde (MDA), superoxide dismutase (SOD), glutathione peroxidase (GPx), glutathione (GSH), phagocytic (PC), respiratory burst (RB), alternative pathway complement (ACP), lysozyme (Lyz), and total immunoglobulin M (IgM) significantly increased in both groups. Similarly, the immune, antioxidant, and anti-inflammatory-related gene mRNA expression was significantly up-regulated in head kidney (HK) tissues. The challenged fish fed without GPF always exhibited lower values of all the studied parameters. The results indicate that both normal and challenged fish treated with 200 mg GPF inclusion diet had significantly enhanced growth rate, antioxidant status, and immune defense mechanisms than with 300 mg GPF diet in L. rohita against F. columnaris., (Copyright © 2021 Elsevier Ltd. All rights reserved.)

The effect of chrysophanic acid (CA) (2, 4, and 8 mg kg -1 ) on the immunity and immune-related gene profile of Catla catla against Aeromonas hydrophila is reported. In both control and treated groups fed with 2 mg kg -1 (2 CA), the phagocytosis, hemolytic, myeloperoxidase content, and superoxide anion production decreased significantly between 6th and 8th weeks, whereas when fed with 4 mg kg -1 CA (4 CA) the H 2 O 2 production and nitric oxide synthase increased significantly between 4th and 8th week. When fed with 2 CA and 4 CA diets, the total protein, bactericidal, and antibody titer increased significantly from the 4th week onwards. When fed with 2 CA, the IL-1β and IL-10 mRNA expression of head kidney leucocytes were significant between weeks 6 and 8. The expressions of toll-like receptors significantly increased when fed with a 4 CA diet from 4th week onwards. The 4 CA group significantly increased in TNF-α, TNF receptor-associated factor 6 (NOD), which influences protein expression, after the 4th week. The mRNA transcription of MHCI, lysozyme-chicken and goose type expressions significantly increased in 4 CA group within the 4th week. In summary, the dietary administration of 4 mg kg -1 of CA (4 CA) provides better immunity and enhances the up-regulation of immune-related genes in Catla against A. hydrophila.