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The application of nanotechnology is significantly revolutionizing the domain of fisheries. Nanotechnology tools are applied to tackle many challenges pertaining to fish productivity, health, reproduction, prevention and treatment of diseases. Fish growth performance can be improved by adding essential minerals in the form of nano-feed supplements. Moreover, nanotechnology is currently assuming a pivotal position in the domain of fish reproduction, alongside its application in fish medicine, including antibacterial therapies, medication delivery mechanisms, and nano-vaccination. Also, there are significant evidences supporting the use of nanotechnology techniques for fish packing and water purification and remediation. In contrast, numerous nanoparticles possess harmful characteristics towards living organisms as a result of their tiny sizes, potent reactivity, and capacity to cross boundaries. They have the ability to modify several physiological activities and induce cytotoxicity, DNA damage, and histopathological alterations. Although nanotechnology has potential for enhancing growth performance and disease resistance in fish, there is ongoing debate about the potential toxicity of nanomaterials, their interactions with the environment, and their propensity to accumulate in animals. This review aims to clarify and analyze the different benefits and challenges associated with the application of nanotechnology in fish farming. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the effects of dietary metformin supplementation on the redox balance, inflammation, mitochondrial biogenesis, and function in blunt snout bream fed a high-carbohydrate (HC) diet. Fish (45.12 ± 0.36 g) were randomly offered four diets, including a control diet (33% carbohydrate), an HC diet (45% carbohydrate), and the HC diet supplemented with 0.06% (HCM1) and 0.12% (HCM2) metformin respectively for 12 weeks. Compared with the control, feeding the HC diet significantly increased the hepatosomatic index (HSI), the mesenteric fat index, liver and muscle glycogen contents, liver and adipose tissue lipid contents, plasma glucose and glycation end products (AGES) levels and aspartate transaminase activity, plasma and liver malondialdehyde (MDA) contents, hepatic adenosine triphosphate (ATP) and adenosine monophosphate (AMP) contents, mitochondrial cytochrome c content, mitochondrial complex IV activity and ATP 6 transcription, but decreased plasma catalase (CAT) activity, muscle superoxide dismutase (SOD) activity, hepatic antioxidant enzymes activities, and the transcriptions of transforming growth factor β (tgfβ) and interleukin 10 (il10). Compared with the HC group, metformin treatment (especially the HCM2 group) significantly elevated tissue glycogen contents, muscle SOD activity, plasma and liver antioxidant enzymes activities, the transcriptions of tgfβ and il10, the sodium/potassium ATPase activity, the contents of mitochondrial protein and AMP, the level of p-AMP activated protein kinase (AMPK), and the p-AMPK/t-AMPK ratio, but lowered the HSI, tissue lipid contents, plasma levels of glucose, AGES and glycated serum protein, plasma, and liver MDA contents, the transcriptions of il1β, NADH dehydrogenase subunit 1 and ATP 6, the contents of ATP and cytochrome c, the ATP/AMP ratio, and the activities of complexes I and IV. In conclusion, metformin could attenuate the HC diet-induced redox imbalance, inflammation, and mitochondrial dysfunction in blunt snout bream. [ABSTRACT FROM AUTHOR]

Abstract Background and aim Contamination from increased anthropogenic activities poses a threat to human health as well as the ecosystem. To develop a nanotechnological approach to improve aqua fisheries, we synthesized magnetic hematite nanoparticle-based gel and evaluated its efficacy in a cadmium-polluted closed system to decontaminate water and improve tilapia fish health. Methods Green iron oxide nanoparticles were biosynthesized by the metabolite of bacillus subtilis and incorporated into polyvinyl alcohol to construct a hydrogel by cryogelation. Key findings The cryogel had interconnected macropores with diameters widely ranging between 20 and 200 μm and could be free-floating in water. When applied in cadmium-polluted tilapia culture, this nanogel reduced turbidity and ammonia in the aquarium, adsorbed cadmium from the water with a larger quantity on the gel’s outer surface than in its center., and reduced cadmium concentration in tilapia’s liver, gills, and muscles. Application of this nano-based cryogel reduced the toxic effects of cadmium on tilapia fish. It maintained hepatic and renal cell nuclear integrity as determined by comet assay. This nano-treatment also reversed the cadmium-induced elevations of plasma lipids, glucose, stress marker cortisol, the hepatic enzymes AST and ALT, and the kidney function marker urea, and improved the lymphocytopenia and other hematological functions in tilapia fish intoxicated by cadmium.

Background and aim: Contamination from increased anthropogenic activities poses a threat to human health as well as the ecosystem. To develop a nanotechnological approach to improve aqua fisheries, we synthesized magnetic hematite nanoparticle-based gel and evaluated its efficacy in a cadmium-polluted closed system to decontaminate water and improve tilapia fish health. Methods: Green iron oxide nanoparticles were biosynthesized by the metabolite of bacillus subtilis and incorporated into polyvinyl alcohol to construct a hydrogel by cryogelation. Key findings: The cryogel had interconnected macropores with diameters widely ranging between 20 and 200 μm and could be free-floating in water. When applied in cadmium-polluted tilapia culture, this nanogel reduced turbidity and ammonia in the aquarium, adsorbed cadmium from the water with a larger quantity on the gel’s outer surface than in its center., and reduced cadmium concentration in tilapia’s liver, gills, and muscles. Application of this nano-based cryogel reduced the toxic effects of cadmium on tilapia fish. It maintained hepatic and renal cell nuclear integrity as determined by comet assay. This nano-treatment also reversed the cadmium-induced elevations of plasma lipids, glucose, stress marker cortisol, the hepatic enzymes AST and ALT, and the kidney function marker urea, and improved the lymphocytopenia and other hematological functions in tilapia fish intoxicated by cadmium.Significance: The nano product of this work has many advantages. It is cheap, green, safe, can be easily manufactured, replaced, or removed from the aquaria, and proven efficient to clean aqua fisheries’ water. The concentration of NPs can be adjusted in the hydrogel, and the utilization of magnetic α-Fe2O3 NPs allows for the removal of the released particles by application of a magnetic field. [ABSTRACT FROM AUTHOR]

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

Objective: The current investigation was conducted to identify existing fish culture practise, livelihood condition of fish farmers, and the major challenges faced by fish farmers in Bhaluka upazila, Bangladesh. Materials and Methods: Data were collected through surveys, monitoring, and participatory rural appraisal (PRA) tools like focus group discussions (FGD), using a preplanned questionnaire survey. A group of 5 fish farmers was interviewed from each of the six villages. Results: In the study, majority of fish farmers were between the ages of 41 and 60 years. Fish farming was their major occupation; however, they did not receive any formal training in fish culture. Fish ponds were large (> 4000 m²) and medium in depth (1-2 m), and the most popular fish culture system was polyculture. Commercial feeds were used to supply nutrients, fertilisers (organic and inorganic) were also applied to the pond water to produce natural food. Salt, lime, zeolite, potassium permanganate, and oxygen tablets were used to maintain water quality. Epizootic ulcerative syndrome, argulosis, and tail and fin rot are most prevalent in the winter. Increasing feed costs, lack of financial support, and disease outbreaks were critical challenges in fish farming in the study area. The socioeconomic status of fish farmers was found to improve with fish farming. Conclusion: Fish farming substantially improved the livelihoods of fish farmers in the study area, despite many constraints. Government support, including microcredit support, the supply of high-quality inputs, including fish fry, feed, vaccinations, and the provision of training facilities could increase fish production in the region. [ABSTRACT FROM AUTHOR]

This study was conducted to investigate the effects of dietary phosphatidylserine (PS) supplementation on the growth performance, stress response, non-specific immunity and antioxidant capacity of juvenile blunt snout bream (Megalobrama ambylcephala) cultured under a high stocking density. A 2 × 2 two-factorial design was adopted, including two stocking densities (10 and 20 fish/m3) and two dietary PS levels (0 and 50 mg/kg). After the 12-week feeding trial, the high stocking density significantly decreased the final weight; weight gain rate; specific growth rate; feed intake; nitrogen retention efficiency; plasma complement 3 (C3) level; albumin/globulin (ALB/GLB, A/G) ratio; activity of myeloperoxidase, lysozyme (LZM) and glutathione peroxidase (GPX); gpx transcription; and abundance of sirtuin3 (Sirt3) and nuclear factor erythroid-2-related factor 2 (Nrf2). However, it significantly increased the plasma levels of cortisol, glucose (GLU), lactic acid (LD), total protein and GLB; hepatic malondialdehyde (MDA) content; and sirt1 transcription. PS supplementation significantly increased the plasma ALB and C4 levels; the A/G ratio; the activity of LZM, CAT and GPX; the transcription of sirt1, nrf2, manganese-containing superoxide dismutase and catalase; and the Nrf2 abundance. However, it significantly decreased the plasma levels of cortisol, GLU and GLB, as well as the hepatic MDA content. In addition, there was a significant interaction between the stocking density and PS supplementation regarding the effects on the plasma LD, ALB, GLB and C3 levels; A/G ratio; hepatic CAT activity; and protein abundance of Sod2. In conclusion, PS supplementation can counteract the high stocking density-induced stress response, redox imbalance and immunosuppression in blunt snout bream. [ABSTRACT FROM AUTHOR]

Aeromonas hydrophila is one of the major freshwater fish pathogens. In the current study, a cocktail of D6 and CF7 phages was given orally to Labeo rohita to assess phage survival in fish organs as well as to determine the therapeutic efficacy of phage treatment against fish mortality caused by A. hydrophila. In the phage-coated feed, prepared by simple spraying method, phage counts were quite stable for up to 2 months with a decline of ≤ 0.23 log10 and ≤ 1.66 log10 PFU/g feed during 4 oC and room temperature storage. Throughout the experimental period of 7 days, both phages could be detected in the gut of fish fed with phage-coated feed. Besides, both CF7 and D6 phages were also detected in fish kidneys indicating the ability of both the phage to cross the intestinal barrier. During challenge studies with LD50 dose of A. hydrophila, phage cocktail doses of 1 × 106 – 1 × 108 PFU/g feed prevented the mortality in L. rohita with relative percentage survival (RPS) of 8.7–65.2. When challenged with LD90 dose of A. hydrophila, an RPS value of 28.6 was obtained at a phage cocktail dose of 1 × 108 PFU/g feed. The RPS data showed that orally-fed phage cocktail protected the fish against the mortality caused by A. hydrophila in a dose-dependent manner. Simple practical approaches for phage cocktail development, medicated feed preparation and oral administration along with phage survival and protection data make the current study useful for farmer-level application. [ABSTRACT FROM AUTHOR]

A number of silk fish-shaped ornaments have been unearthed from the beacon towers and tombs sites of the Han and Jin dynasties in Dunhuang and Tarim Basin. Based on other ancient objects from the same site, it can be concluded that the silk fish-shaped ornaments was a product of the Han culture. Its popularity in the northwest was related to the Central Plain Dynasty's exploration of the western regions. The western spread of Central Plain's fish culture relied on the local custom of eating fish. Combined with the image of fish in Han culture and the cultural background of northwest China, the silk fish-shaped ornaments might have the functions of praying for fertility, auspicious omen and ceremony of assisting in ascension. The silk fish shaped ornaments unearthed in the Tarim Basin are all from higher-level tombs, showing the deep recognition of the Chinese culture by the ethnic groups in the western regions. The archaeological evidence also proves that the western regions had been an important part of the Chinese ethnic community since the Han dynasty. [ABSTRACT FROM AUTHOR]

This study aimed to assess the function of γ-aminobutyric acid (GABA) on growth performance, food intake and glucose homeostasis of Micropterus salmoides fed carbohydrate (CHO)-enriched diets. The intracerebroventricular glucose + GABA co-injected fish had higher cumulative food intake, and expression of orexigenic genes (ghrelin and neuropeptide y (npy)) in the brain than those of the single glucose-injected group. In the feeding trial, M. salmoides (10.35 ± 0.05 g) were fed four feeds containing a control feed (10 % CHO, C) and three GABA contents [0 (HC), 50 (HC-G1), and 100 (HC-G2) mg kg−1, respectively] of high-CHO feed (20 % CHO) for 12 weeks. High CHO prominently (P < 0.05) decreased WGR, SGR, FI, p-Ampk protein content, and expression of ghrelin, npy, fbpase, pparα, cpt1α and aco1 compared with the control group, but the opposite was true for plasma glucose and triglyceride levels, tissue glycogen and lipid contents, and expression of proopiomelanocortin, leptin a, gk, pk, gs, chrebp, srebp1, fas and acc1. HC-G2 diets prominently (P < 0.05) up-regulated WGR, SGR, FI, p-Ampk protein content, and expression of ghrelin, npy, gk, pk, chrebp, srebp1, fas and acc1 compared with the HC group. Also, HC-G2 diets increased glucose tolerance of M. salmoides fed high-CHO diets after glucose loading. Overall, GABA improved the growth performance, food intake and glucose homeostasis of high-CHO-fed fish by the increase of appetite, glycolysis, glycogenesis and lipolysis, as well as the inhibition of gluconeogenesis and lipid synthesis.

In Madagascar, fish farming is a complementary activity to agriculture, developed mainly in the highlands region. The common carp, Cyprinus carpio L., is the main species farmed. The availability of fingerlings is one of the key constraints facing the sector. The present study shows the benefit of an appropriate feed and feeding regime to both broodfish and larvae/fry and also the positive impact of protecting larvae during the first stages of their life by using happa system. The combination of these technical approaches increases significantly carp fry production. [ABSTRACT FROM AUTHOR]

With the continuous expansion of the scale of fish farming in China, feed additives in fish farming have been widely concerned. Chinese herbal additives are widely used in fish farming because of their natural raw materials, small toxic side effects and pollution-free advantages. By discussing the characteristics and application of Chinese herbal additives, this paper expounds the role and application prospect of Chinese herbal additives in fish culture, in order to provide guidance for the application of Chinese herbal additives in fish culture. [ABSTRACT FROM AUTHOR]

Abstract In Madagascar, fish farming is a complementary activity to agriculture, developed mainly in the highlands region. The common carp, Cyprinus carpio L., is the main species farmed. The availability of fingerlings is one of the key constraints facing the sector. The present study shows the benefit of an appropriate feed and feeding regime to both broodfish and larvae/fry and also the positive impact of protecting larvae during the first stages of their life by using happa system. The combination of these technical approaches increases significantly carp fry production.

Adding immune enhancers to feed can maintain fish health and enhance disease resistance. Some insects contain rich bioactive substances, which can improve the health of fish, among which the Black soldier fly is more studied and applied. Black soldier fly is rich in nutrition, short growth and reproduction cycle, high feed utilization rate, low feeding pollution, and rich in antimicrobial peptides, chitin and lauric acid, which has broad application prospects as an immune booster and health promotion agent in fish culture. In the paper, the biological characteristics and principle of Black soldier fly as immune enhancer are summarized, the application of Black soldier fly in various fish immune enhancer in recent years is summarized, and the appropriate proportion and form of replacing fish meal and other feed ingredients are discussed, to provide reference for the efficient application of Black soldier fly in fish culture. [ABSTRACT FROM AUTHOR]

This study was conducted to investigate the effects of dietary phosphatidylserine (PS) supplementation on the growth performance, stress response, non-specific immunity and antioxidant capacity of juvenile blunt snout bream (Megalobrama ambylcephala) cultured under a high stocking density. A 2 × 2 two-factorial design was adopted, including two stocking densities (10 and 20 fish/m3) and two dietary PS levels (0 and 50 mg/kg). After the 12-week feeding trial, the high stocking density significantly decreased the final weight; weight gain rate; specific growth rate; feed intake; nitrogen retention efficiency; plasma complement 3 (C3) level; albumin/globulin (ALB/GLB, A/G) ratio; activity of myeloperoxidase, lysozyme (LZM) and glutathione peroxidase (GPX); gpx transcription; and abundance of sirtuin3 (Sirt3) and nuclear factor erythroid-2-related factor 2 (Nrf2). However, it significantly increased the plasma levels of cortisol, glucose (GLU), lactic acid (LD), total protein and GLB; hepatic malondialdehyde (MDA) content; and sirt1 transcription. PS supplementation significantly increased the plasma ALB and C4 levels; the A/G ratio; the activity of LZM, CAT and GPX; the transcription of sirt1, nrf2, manganese-containing superoxide dismutase and catalase; and the Nrf2 abundance. However, it significantly decreased the plasma levels of cortisol, GLU and GLB, as well as the hepatic MDA content. In addition, there was a significant interaction between the stocking density and PS supplementation regarding the effects on the plasma LD, ALB, GLB and C3 levels; A/G ratio; hepatic CAT activity; and protein abundance of Sod2. In conclusion, PS supplementation can counteract the high stocking density-induced stress response, redox imbalance and immunosuppression in blunt snout bream.

Summary: Viral inclusion bodies (VIBs) are subcellular structures required for efficient viral replication. How type II grass carp reovirus (GCRV-II), the mainly prevalent strain, forms VIBs is unknown. In this study, we found that GCRV-II infection induced punctate VIBs in grass carp ovary (GCO) cells and that non-structural protein 38 (NS38) functioned as a participant in VIB formation. Furthermore, VP56 and VP35 induced VIBs and recruited other viral proteins via the N-terminal of VP56 and the middle domain of VP35. Additionally, we found that the newly synthesized viral RNAs co-localized with VP56 and VP35 in VIBs during infection. Taken together, VP56 and VP35 induce VIB formation and recruit other viral proteins and viral RNAs to the VIBs for viral replication, which helps identify new targets for developing anti-GCRV-II drugs to disrupt viral replication.

The submerged surface sediment of the artificial lake at Jordan University of Science and Technology in Irbid, Jordan, was investigated to evaluate its contamination with trace metals. Chemical characterization was applied to leachates of sediment samples collected from 11 sampling stations at the study zone. The metal concentration (Pb, Cu, Cr, Cd, Ni, Zn, Fe, and Hg) in the sediment samples was matched to the limits set by the Jordanian standard for water-sludge-uses of treated sludge and sludge disposal. According to the results obtained via thermal decomposition, mercury amalgamation, and inductively coupled plasma—atomic emission spectrometry (ICP-AES), most metals were below the detection limit. Several metals were found to be below the limits fixed by the Jordanian standards except for stations 10 and 11 which connected the wastewater channels to the lake. At these two stations, Pb recorded contents were 439 and 335 mg/kg dry matter, respectively, and thus exceeded the limits set by the Jordanian standard. Thus, the overall results were in favor of the environmental safety of the JUST lake for setting up a fish aquaculture. [ABSTRACT FROM AUTHOR]

Mugil cephalus is an estuarine species that has been shown to acclimate to a diversity of environmental conditions being a good candidate to diversify aquaculture. The objective of this study was to evaluate the growth and water quality of M. cephalus juveniles in a biofloc technology system (BFT). Over a period of 87 days, mullet juveniles (117.36 ± 6.48 g) were reared in two experimental conditions: water exchange (control group) (50% three times a week) and BFT (C:N ratio of 15:1). M. cephalus juveniles were stocked at a density of 7.2 kg·m−3. Water quality parameters were monitored periodically. Fish were fed with a balanced artificial feed for marine fish (2% of the total biomass). The water quality parameters were similar between the treatments, with the exception of pH, alkalinity, TSS, and N-NO3 (p < 0.05). Zootechnical parameters WG, DWG, BG, SGR, condition factor, and survival did not show significant differences (p > 0.05). The biomass gain was higher in BFT (p < 0.05). Water quality variables did not appear to influence mullet survival under culture conditions. Mullet is a species that can be reared in BFT without compromising productive performance and having a significant saving of water. [ABSTRACT FROM AUTHOR]

In aquaculture, drugs are often abused to accomplish disease control without considering the negative effects on fish health. This study aimed at elucidating the pernicious effects of in-feed antiparasitic drug emamectin benzoate (EB) abuse on the haemato-biochemistry and erythro-morphometry of healthy Nile tilapia Oreochromis niloticus. The fish were fed EB at 50 μg (1×) and 150 μg/kg biomass/d (3×) for 14 d as against the recommended 7 d and periodically assessed the blood parameters. A significant dose- and time-dependent reduction in feed intake, survival, total erythrocytes (TEC), monocytes (MC), hemoglobin (Hb), hematocrit (Ht) and mean corpuscular Hb concentration were noted. The total leukocytes (TLC), thrombocytes (TC), lymphocytes (LC) and neutrophils (NC) markedly augmented. The EB-dosing altered the fish physiology by enhancing the glucose, alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP) and creatinine and reducing the calcium, chloride and acetylcholinesterase (AChE) levels dose-dependently. The fish recovered within 4 weeks in the 1× group post-dosing but persevered in the overdosed group. The erythro-cellular and nuclear dimensions were reduced with the increase in dose and normalized after the cessation of dosing, except for nuclear volume. The erythro-morphological alterations were more prominent in the overdosed group. The results implied the pernicious effect of oral EB medication on the biological responses of fish if abused. [ABSTRACT FROM AUTHOR]

Summary: Although most B cells in teleost systemic compartments co-express IgM and IgD on the surface, cells exclusively expressing either of the two Igs are common in fish mucosal tissues, providing us with a unique opportunity to further characterize IgD+IgM− B cells, an intriguing B cell subset. Hence, we compared the phenotype of IgD+IgM− cells to that of IgM+IgD− B cells in rainbow trout gills and skin, also establishing the response of these subsets to immune stimulation. The transcriptional profile and secreting capacity of IgD+IgM− B cells corresponded to that of cells that have started a differentiation program toward plasmablasts, similarly to IgM+IgD− B cells. Yet, IgM+IgD− B cells retained high levels of surface MHC II and antigen-processing abilities, while these were much lower in IgD+IgM− cells, suggesting important differences in their antigen-presenting capacities. Our findings contribute to a deeper understanding of the enigmatic role of IgD in mucosal surfaces.

The study was performed to evaluate the effects of the reduced lactate production by sodium oxamate (SO) on growth performance, lactate and glucose and lipid metabolism, and glucose tolerance of Micropterus salmoides fed high-carbohydrate (CHO) diets. In in vitro study, primary hepatocytes were incubated for 48 h in a control medium (5.5 mM glucose), a high-glucose medium (25 mM glucose, HG), or a SO-containing high-glucose medium (25 mM glucose þ 50 mM SO, HG-SO). Results indicated lactate and triglyceride (TG) levels, and lactate dehydrogenase a (LDH-a) expression in the HG-SO group were remarkably lower than those of the HG group. In in vivo study, M. salmoides (5.23 ± 0.03 g) were fed four diets containing a control diet (10% CHO, C) and three SO contents [0 (HC), 100 (HC-SO1), and 200 (HC-SO2) mg·kg-1, respectively] of high-CHO diets (20% CHO) for 11 wk. High-CHO diets significantly reduced weight gain rate (WGR), specific growth rate (SGR), p-AMPK-to-t-AMPK ratio, and expression of insulin receptor substrate 1 (IRS1), insulin-like growth factor I (IGF-I), insulin-like growth factor I receptor (IGF-IR), fructose-1,6-biphosphatase (FBPase), peroxisome proliferator-activated receptor a (PPARa), and carnitine palmitoyl transferase 1a (CPT1a) compared with the C group, whereas the opposite was true for plasma levels of glucose, TG, lactate, tissue glycogen, and lipid contents, and expression of LDH-a, monocarboxylate transporter 1 and 4 (MCT1 and MCT4), insulin, glucokinase (GK), pyruvate dehydrogenase E1 subunit (PDH), sterol-regulatory element-binding protein 1 (SREBP1), fatty acid synthase (FAS). The HC-SO2 diets remarkably increased WGR, SGR, p-AMPK-to-t-AMPK ratio, and expression of IRS1, IGF-I, IGF-IR, GK, PDHa, PDHb, FAS, acetyl-CoA carboxylase 1 (ACC1), PPARa, and CPT1a compared with the HC group. Besides, HC-SO2 diets also enhanced glucose tolerance of fish after a glucose loading. Overall, the reduced lactate production by SO benefits growth performance and glucose homeostasis of high-CHO-fed M. salmoides through the enhancement of glycolysis, lipogenesis, and fatty acid b-oxidation coupled with the suppression of glycogenesis and gluconeogenesis. [ABSTRACT FROM AUTHOR]

The present work aimed at assessing the possibility of compensating the notorious deficiencies of bioflocs in lipids by supplementing the tilapia commercial diet with soybean oil. In the positive control, there was no feeding restriction nor dietary supplementation with soybean oil. In the experimental treatments, the commercial diet was restricted by 25% over the positive control level. In the negative control tanks, there was feeding restriction and the artificial diet had no oil supplementation. In the experimental tanks, soybean oil was mixed daily with the commercial diet at the levels of 0.6%, 1.2 and 2.4%. Additionally, there were fed-restricted tanks that received a daily supplementation of 1.2% soybean oil mixed with dry molasses, and not with the commercial diet. In general, only the restriction of the commercial diet affected the water quality. The supplementation of the artificial diet with soybean oil up to 2.4% has not improved the proximate composition of bioflocs, nor the fish growth performance. It was concluded that the strategy of supplementing the Nile tilapia juveniles’ commercial diet with increasing levels of soybean meal, in BFT tanks submitted to 25%-feeding restriction, was not capable of avoiding the fish growth performance deterioration.

The work aimed at determining the effects of applying different blends between liquid molasses and agricultural limestone on water quality and growth performance of Nile tilapia juveniles, Oreochromis niloticus. The study employed 24 indoor tanks of 100 L and 24 outdoor tanks of 250 L. Four control groups were set up (no product applied, only molasses, only limestone, molasses-limestone blend with 48% limestone but no fish) and two experimental groups (molasses-limestone blends with 32% and 48% molasses), with four replicates each. Over 11 weeks, the water quality was monitored systematically. The 24-h cycle monitoring of temperature, pH, specific conductance, dissolved O2 and total alkalinity were carried out at the 8th week. The blends between molasses and limestone accelerated the dissolution rate of the agricultural limestone in water. The blend containing 48% molasses led to greater increases in water alkalinity and pH in relation to tanks with only limestone applications. However, the molasses-limestone blend applications impaired the Nile tilapia growth performance, especially in the outdoor tanks. While the fish yield was 25.1 g m-3 day-1 in the molasses outdoor tanks, it was equal to 22.8 g m-3 day-1 in the molasses (32%)-limestone units (P

It is estimated that vibriosis account for about half of the economic losses in Asian fish culture. Consequently, the prevention and control of vibriosis is one of the priority research topics in the field of Asian fish culture disease. Relevant measures have been proposed to control some Vibrios that pose a threat to Asian fish culture, but there are currently only a few effective vaccines available to combat these Vibrios. The purpose of our review is to sum up the main prevention methods and the latest control strategies of seven Vibrio species that cause great harm to Asian aquaculture, including Vibrio harveyi, Vibrio vulnificus, Vibrio parahaemolyticus, Vibrio mimicus, Vibrio anguillarum, Vibrio alginolyticus and Vibrio cholerae. Strategies such as antibiotics, probiotics, bacteriophages, antimicrobials from plants and other natural sources, as well as vaccines, are compared and discussed here. We expect this review will provide some new views and recommendations for the future better prevention and control of vibriosis in Asian fish culture. [ABSTRACT FROM AUTHOR]

The experiment was carried out in eighteen outdoor cemented tanks (5m × 4m × 1m) for a period of 100 days at College of Fisheries, Lembucherra to evaluate the length-weight relationship and condition factor of Labeo catla, Labeo rohita and Labeo gonius were worked out under different treatment. Tanks were initially dried, cleaned and treated with quick lime (CaO) at the rate of 200 g/tank and then filled with ground water. After a week of liming all the tanks were fertilized with cow dung at a basal dose of 2 kg/tank. Fertilization dose were the same for all the treatments. The tanks were provided with a soil base of 6-8 cm. The fingerlings of Labeo catla (Hamilton, 1822) were obtained from local farmers, Labeo rohita (Hamilton, 1822) and Labeo gonius (Hamilton, 1822) were collected from the rearing ponds and were stocked in 18 experimental tanks at three different stocking densities, viz. 1 no.m-2, 2 nos.m-2 and 3 nos m-2 at a stocking ratio of 1:1:1 in uniform size with and without feeding treatment having 3 replicates. Physico-chemical parameters of the experimental tank were taken 20 days interval and were within the normal ranges for fish culture. Length –weight relationship for T2 treatment were shows higher value than other treatment 0.558 L2.796 for catla, 0.844 L 2.663 for rohu and in case of gonis 0.713 L1.853. Feeding treatment shows higher b values (2.796 for catla and 2.663 for rohu at T2 treatment and 1.853 for gonius at T4 Treament) than without feeding treatments even though all the treatment were treatment negatively alometric value. The ‘b’ value of different treatment were lower than critical isometric value i.e. 3.0 indicating negative allometric growth pattern in all species under different. [ABSTRACT FROM AUTHOR]

The work aimed at determining the effects of applying different blends between liquid molasses and agricultural limestone on water quality and growth performance of Nile tilapia juveniles, Oreochromis niloticus. The study employed 24 indoor tanks of 100 L and 24 outdoor tanks of 250 L. Four control groups were set up (no product applied, only molasses, only limestone, molasses-limestone blend with 48% limestone but no fish) and two experimental groups (molasses-limestone blends with 32% and 48% molasses), with four replicates each. Over 11 weeks, the water quality was monitored systematically. The 24-h cycle monitoring of temperature, pH, specific conductance, dissolved O2 and total alkalinity were carried out at the 8th week. The blends between molasses and limestone accelerated the dissolution rate of the agricultural limestone in water. The blend containing 48% molasses led to greater increases in water alkalinity and pH in relation to tanks with only limestone applications. However, the molasses-limestone blend applications impaired the Nile tilapia growth performance, especially in the outdoor tanks. While the fish yield was 25.1 g m-3 day-1 in the molasses outdoor tanks, it was equal to 22.8 g m-3 day-1 in the molasses (32%)-limestone units (P<0.05). It has been concluded that the blending between limestone and molasses brings no clear benefits to Nile tilapia's rearing tanks when compared to the limestone-only tanks. [ABSTRACT FROM AUTHOR]

This study aimed to characterize the effects of resveratrol on the redox balance, cholesterol homeostasis and bile acid metabolism of Megalobrama amblycephala offered a high-carbohydrate diet. Fish (35.0 ± 0.15 g) were fed four diets including one control diet (32% nitrogen-free extract), one high-carbohydrate diet (45% nitrogen-free extract, HC), and the HC diet supplemented with different levels (0.04%, HCR1; 0.08%, HCR2) of resveratrol for 12 weeks. The HC diet-induced redox imbalance is characterized by increased MDA content and decreased T-SOD and CAT activities in the liver. Resveratrol attenuated this by up-regulating the transcription of Cu/Zn-sod, and increasing the activities of T-SOD, CAT, and GPX. The HC diet enhanced the cholesterol synthesis, but decreased the bile acid synthesis via up-regulating both hmgcr and acat2, and down-regulating cyp7a1, thus resulting in excessive cholesterol accumulation. Resveratrol supplement decreased cholesterol synthesis, and increased cholesterol uptake in the liver by down-regulating both hmgcr and acat2, and up-regulating ldlr. It also increased bile acid synthesis and biliary excretion by up-regulating cyp7a1, and down-regulating mrp2, oatp1, and oatp4 in the hindgut, thereby decreasing cholesterol accumulation. In conclusion, resveratrol improves the cholesterol homeostasis of Megalobrama amblycephala fed a high-carbohydrate diet by modulating the redox response and bile acid metabolism. [ABSTRACT FROM AUTHOR]

Mugil cephalus is an estuarine species that has been shown to acclimate to a diversity of environmental conditions being a good candidate to diversify aquaculture. The objective of this study was to evaluate the growth and water quality of M. cephalus juveniles in a biofloc technology system (BFT). Over a period of 87 days, mullet juveniles (117.36 ± 6.48 g) were reared in two experimental conditions: water exchange (control group) (50% three times a week) and BFT (C:N ratio of 15:1). M. cephalus juveniles were stocked at a density of 7.2 kg·m−3. Water quality parameters were monitored periodically. Fish were fed with a balanced artificial feed for marine fish (2% of the total biomass). The water quality parameters were similar between the treatments, with the exception of pH, alkalinity, TSS, and N-NO3 (p < 0.05). Zootechnical parameters WG, DWG, BG, SGR, condition factor, and survival did not show significant differences (p > 0.05). The biomass gain was higher in BFT (p < 0.05). Water quality variables did not appear to influence mullet survival under culture conditions. Mullet is a species that can be reared in BFT without compromising productive performance and having a significant saving of water.

Striped bass, Morone saxatilis, is a marine species that belongs to the Moronidae family, which has great recreational and commercial importance and high production potential for human consumption. This research examines two acute stress factors that can be frequent in fish production units: a) handling is carried out constantly due to maintenance needs, size separation, growth evaluation, and health state, and b) hypoxia likely occur as the culture tank biomass, temperature, and fish metabolic rate increase. Juvenile fish (initial body weight 200 ± 3.0 g) were distributed in 110 L tanks and fed one week with different dietary tryptophan (Trp) levels: CD0.5 (0.5%), D1.0 (1.0%), D1.5 (1.5%) and D2.0 (2.0%). The fish were then exposed to stress by handling (5 min) or hypoxia (45 min). After that, blood hematocrit (Hct), hemoglobin (HB) and plasma cortisol, glucose (GLU), lactate (LACT), total protein (TP), albumin (AL), and globulin (GLOB) were analyzed, and AL/GLOB ratio was calculated. All analyzed parameters showed great sensitivity to acute stressors. Hypoxia increased Hct, cortisol, and GLU and decreased HB and LACT. Handling decreased HB and TP and increased GLU and LACT. D1.0 and D1.5 prevented Hct and LACT disturbance. D1.5 Trp prevented HB disturbance. All Trp supplemented diets prevented GLU change under hypoxia and TP change after handling. The results suggest that Trp played a role in M. saxatilis homeostasis restoration under acute stress. [ABSTRACT FROM AUTHOR]

Nowadays, both pelleted feed (PF) and extruded feed (EF) have been widely adopted in the aquaculture industry. However, limited information is available comparing their utilization efficiencies and meanwhile interpreting the underlying mechanisms. This study aimed to compare the utilization efficiencies of both PF and EF by blunt snout bream (Megalobrama amblycephala) based on growth performance, digestive capacities, and endocrine functions. Two feeds with identical formulas were prepared and named PF and EF. Fish were randomly distributed into two groups, including one that fed the PF continuously, and one that offered the EF continuously. The whole feeding trail lasted 8 weeks. The results showed that the protein efficiency (PER), retention of nitrogen and energy (NRE and ERE), viscera index (VSI), apparent digestibility of dry matter, protein, carbohydrate, and gross energy, whole-body crude protein and energy contents, intestinal enzymatic activities of protease, amylase, and Na+,K+-ATPase, intestinal villi length, crypt depth, muscular layer thickness, and the transcriptions of leptin (LEP) and cholecystokinin (CCK) of the EF group were all significantly higher than those of the PF group, while the opposite was true for feed intake and feed conversion ratio. These findings suggested that compared with PF, EF could improve the feed utilization and nutrient retention of blunt snout bream by enhancing the intestinal digestive and absorptive functions but reduce the feed intake through the stimulation of both LEP and CCK. [ABSTRACT FROM AUTHOR]

Currently, tilapia farming focuses on efficient use of water in reducing nitrogen waste by implementing aquaponics systems. The application of an aquaponic system has advantages not only for producing fish but also plants.This research was carried out for 1 month with different types of plants used, namely water spinach (Ipomoea reptans), pakcoy (Brassica rapa L), and control. Each treatment was repeated 3 times. Tilapia fish were used in this study ranging at 8-10 cm in an aquarium (60x40x30 cm) with a stocking density of 1 fish/2 liters. Parameters observed included gill histopathology and water quality (ammonia, nitrite and nitrate). The results showed that the damage of fish gill found in the form of hyperflasia, fusion and hemorrhage. The lowest damage to fish gill tissue occurred in treatment A (water spinach) with a score of hyperplasia (0.73), fusion (0.07) and hemorrhage (1.33). The best water quality was obtained in treatment A (water spinach) with values of ammonia (0.25 mg/l), nitrite (0.174 mg/l), and nitrate (1.058 mg/l).There is a correlation between the amount of damage to the fish gills and the quality of the water in the rearing media in which the higher the concentration of ammonia and nitrite, the greater the level of damage obtained. Thus, water spinach is the effective plant to utilize nitrogen as an essential nutrient for growth in the aquaculture system.

The widespread use of antibiotics against aquaculture diseases also triggers the emergence of immunosuppression, antibiotic residues, antibiotic resistance genes, and environmental damage in cultured fish globally, thus resulting in the banning of many antibiotics. As a safer and more effective antibacterial product, the probiotic Clostridium butyricum (C. butyricum) has been increasingly used as additives in aquaculture to overcome the abuse of antibiotics and to promote fish health and their productivity. To date, studies in fish culture focus on the beneficial effects of C. butyricum on growth performance, antioxidant properties, intestinal microbiota, intestinal immune and health, and disease resistance. Therefore, C. butyricum is likely to become a potential alternative to antibiotics for prevention of enteric pathogen infection and related diseases. This paper systematically reviews the latest research and application progress of probiotic C. butyricum strains in fish culture. The focus of this review is a discussion of the beneficial effects of C. butyricum on diverse fish species, specifically the underlying mechanisms of C. butyricum in promoting growth, and improving disease resistance and the associated immune response. To realize large-scale application in the aquaculture industry, it is essential to conduct further investigation of the interrelationships between the C. butyricum and the immune system of the host, and the C. butyricum -triggered signaling pathways to secure the trials further. [Display omitted] • The mechanisms of Clostridium butyricum in the host immune system were summarized. • The beneficial effects of Clostridium butyricum on fish farming were analyzed. • The safety of Clostridium butyricum in fish farming was evaluated. [ABSTRACT FROM AUTHOR]