Maximization of brackish water productivity for the sustainable production of striped catfish (Pangasianodon hypophthalmus) and grain sorghum (Sorghum bicolor (L.) Moench) cultivated under an integrated aquaculture-agriculture system.

Freshwater scarcity, salinity, and poor soil fertility are the major challenges affecting both food and feed productions in arid and semi-arid regions of the world. Utilization of brackish water in the production of saline-tolerant fish and valuable field crops under an integrated system is promising in the maximization of yield per crop. The aim of this study, therefore, was to (1) assess the effect of saline aquaculture wastewater on the growth, yield, forage quality, and nutritive composition of sorghum seeds and (2) assess the effect of different water qualities on the survival, growth performance, and health status of Pangasianodon hypophthalmus. The experiment was conducted in a randomized completely block design of four salinity treatments with three replicates, i.e., control (freshwater mixed with inorganic fertilizers), 5000 ppm, 10,000 ppm, and 15,000 ppm. Our results indicated that although the control exhibited the highest growth (plant height, leaf number, internode number, leaf area, and soil-plant analysis development), grain, and forage yield, no significant differences were noted among the treatments. Likewise, no significant difference in the grain nutrient composition was noted among all the treatments. Assessment of the forage quality revealed improved crude protein content in the control compared to the saline treatments. However, no significant differences in the leaves and stalks fiber fractions were noted among all the treatments. Furthermore, rumen fermentation in terms of in vitro digestibility indicated no significant differences in the in vitro digestible dry matter, digestible organic matter, metabolic energy, net energy, microbial protein, short-chain fatty acids, and total dissolved nutrients among the treatments. However, rearing P. hypophthalmus in water salinities exceeding 10,000 ppm reduced the growth performance and health status of fish. Therefore, the integration of sorghum and P. hypophthalmus production in water salinities not exceeding 5000 ppm is a viable alternative to maximize brackish water productivity in freshwater-scarce regions.

Coping with Water Stress: Ameliorative Effects of Combined Treatments of Salicylic Acid and Glycine Betaine on the Biometric Traits and Water-Use Efficiency of Onion (Allium cepa) Cultivated under Deficit Drip Irrigation.

Freshwater scarcity is a major global challenge threatening food security. Agriculture requires huge quantities of water to feed the ever-increasing human population. Sustainable irrigation techniques such as deficit drip irrigation (DDI) are warranted to increase efficiency and maximize yield. However, DDI has been reported to cause water stress in plants. The study aimed to investigate the influence of the exogenous application of salicylic acid alone (SA) or in combination with glycine betaine (GB) on the growth, yield quality, and water-use efficiency of onions under different DDI treatments (100%, 70%, and 40% field capacity (FC)). Spray treatments (sub-treatments) were as follows: T1: (distilled water), T2: (1.09 mM SA), T3: (1.09 mM SA + 25 mM GB), T4: (1.09 mM SA + 50 mM GB), and T5: (1.09 mM SA + 100 mM GB). Our results indicated that T2 slightly ameliorated the effects of water stress by improved plant heights, leaf number, pseudostem diameter, bulb quality, and nutrient content of onion bulbs, especially under the 70% FC treatment. However, T3 recorded the poorest results on leaf number, pseudostem diameter, and bulb quality under the 70% and 40% FC treatments. Generally, our results indicated that onions could tolerate moderate water stress (70% FC) without severely affecting the growth and yield of onion. In conditions where freshwater is a limiting factor, a DDI treatment of 40% FC is recommended.

Combined effects of water salinity and ammonia exposure on the antioxidative status, serum biochemistry, and immunity of Nile tilapia (Oreochromis niloticus).

Growing Nile tilapia in brackish water showed promising results, but the possibility of ammonia exposure can interrupt health status and productivity. Herein, the study tested the combined effects of water salinity and ammonia exposure on the antioxidative status, serum biochemistry, and immunity of Nile tilapia. Fish were assigned to eight groups where fish were reared in saline water (5, 10, and 15 ppt) with continuous or intermittent (every 3 days) total ammonia (TAN) exposure (5 mg TAN/L) (2 × 4 factorial design). After 30 days, the water salinity, TAN, and their interaction were markedly (P < 0.05), affecting the growth performance (final weight, weight gain, and specific growth rate) and survival rate of Nile tilapia. The growth performance and survival rate were markedly lower in tilapia grown in 15 ppt with continuous TAN exposure than in the remaining groups. The results showed that fish exposed to higher salinity levels (10 and 15 ppt) and continuous TAN exposure had a more robust antioxidative response, as evidenced by higher superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPX) activities and lower malondialdehyde (MDA) levels in the homogenates of the gills, intestines, and livers. The gills were notably affected, with congestion of primary filaments blood vessels and degeneration or shedding of secondary filaments epithelium, especially at salinity levels of 10 and 15 ppt. Additionally, the intestines displayed hyperplasia and inflammatory cell infiltration of intestinal mucosa at 5-10 ppt salinity, degeneration and sloughing of the intestinal epithelium at 15 ppt saline water, and increased goblet cell number at salinity of 10 ppt. The study found that continuous TAN exposure had a more significant impact on the fish, especially at higher salinity levels. Water salinity, TAN, and their interaction significantly affected all measured blood bio-indicators (total, albumin, globulin, ALT, AST, creatinine, urea, glucose, and cortisol levels). The phagocytic activity and index were markedly lowered in fish reared in 15 ppt with continuous TAN exposure, while the lysozyme activity was decreased in fish grown in 5, 10, and 15 ppt with continuous TAN exposure. In conclusion, Nile tilapia showed the possibility of growth with normal health status in brackish water (5-10 ppt); however, continuous TAN exposure can impair the productivity of tilapia, especially with high salinity (15 ppt).

Influence of salinity on the biometric traits of striped catfish (Pangasianodon hypophthalmus) and barley (Hordeum vulgare) cultivated under an integrated aquaculture-agriculture system.

BACKGROUND: Soil salinity, soil infertility, and freshwater scarcity are among the major constraints affecting agricultural ecosystems in arid and semi-arid regions of the world. Hence, there is a need to look for salt-tolerant crops and fish that can be successfully cultivated and reared respectively in such harsh environments. The implementation of biosaline integrated aquaculture-agriculture systems (IAAS) utilizing both salt-tolerant crops and fish could improve food and feed production in arid and semi-arid regions. This study, therefore, investigated the influence of salinity on the biometric traits of striped catfish (Pangasianodon hypophthalmus) and barley (Hordeum vulgare) under an IAAS. METHOD: The experiment followed a randomized completely block design of three salinity treatments with three replicates namely, T0: Control (freshwater mixed with chemical fertilizers), T1: 5,000 ppm, T2: 10,000 ppm, and T3: 15,000 ppm. RESULTS: Irrigating barley with saline aquaculture wastewater at different salinities (5,000 ppm, 10,000 ppm, and 15,000 ppm) did not significantly affect the agro-morphological parameters (internode number per plant, stalk diameter, leaf number per plant, leaf area index, and leaf chlorophyll content (SPAD)) of the plants at 90 days after sowing. Moreover, the forage yield and forage quality in terms of fiber fraction, nutrient composition, and in vitro digestibility of the forage biomass were not severely affected by high salinity compared to the control (freshwater and inorganic fertilizers). Our results also showed that rearing striped catfish in saline water not exceeding 10,000 ppm did not negatively impact the growth performance (final weight, body weight gain, feed conversion ratio, specific growth rate, condition factor, and survival) and the health status of the fish. CONCLUSIONS: The integration of striped catfish and barley production in water salinities below 15,000 ppm could be a feasible alternative in safeguarding food and feed security in regions affected by soil salinity, soil infertility, and freshwater scarcity. Moreover, the salinity regime of 5,000 ppm could bring higher economic gains to farmers regarding higher crop yields (fish and forage yield).

Biofouling mechanism and cleaning procedures for Spirulina platensis as an organic fertilizer draw solution.

The forward osmosis (FO) desalination process has recently acknowledged a lot of attention as a promising solution for reducing the disadvantages of existing desalination systems. This work aimed to investigate the effect of a selected liquid organic fertilizer a novel draw solution produced from "microalgae Spirulina platensis" on the biofouling mechanism of FO membrane. Different draw solution (DS) concentrations ranging 240-480 g/L were examined, obtained water flux ranging from 6.5 to 3.4 Lm2h-1. A high flux decline was observed when using higher DS concentrations due to fouling layer accumulated throughout the membrane area which lowers the effective osmotic pressure difference. Different cleaning strategies were examined. The biofouled membrane was cleaned on-line with deionized water (DI) and externally using ultrasound (US) and HCl. Baseline experiments were done to investigate the efficiency of the cleaning strategies. After cleaning using the deionized water (DI) water, it was found that the water flux progressed from 3.4 to 7 Lm2h-1, while when using acid cleaning the flux recovered to 15 Lm-2h-1. The efficacy and amount of foulant removed by each cleaning stage were assessed using scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX).

Growth response of kale (Brassica oleracea) and Nile tilapia (Oreochromis niloticus) under saline aqua-sandponics-vegeculture system.

Salinity and freshwater scarcity are significant challenges affecting agriculture production worldwide. Sustaining food production in arid and semi-arid regions requires innovative, efficient, and low-cost technologies. Integrated aqua-vegeculture systems (IAVS) are promising technologies for cultivating vegetable crops and rearing fish and in a closed-loop system. The system utilizes fish effluents as crop fertilizers and recycles water for increased productivity. Hence, the current study aimed to investigate the response and productivity of kale (Brassica oleracea L.) grown at different brackish water salinities in an IAVS. The greenhouse experiment followed a completely randomized design with three salinity variants (i.e., 3000, 6000, and 9000 ppm) and control (freshwater, 400 ppm) with four replicates per treatment. The study results indicated that kale grown in a greenhouse could tolerate salinity levels of up to 6000 ppm without significantly compromising the plants' growth, yield, and nutritional composition of leaves. Likewise, rearing Oreochromis niloticus at high water salinities did not negatively impact the water quality and the growth performance, survival, and feed utilization of fish. Overall, cultivating kale and rearing O. niloticus in IAVS in water salinities reaching up to 6000 ppm could be a sustainable agricultural strategy to increase food production in regions affected by freshwater scarcity.

The combined effects of salinity and ammonia on the growth behavior, stress-related markers, and hepato-renal function of common carp (Cyprinus carpio).

One of the most critical factors affecting aquaculture efficiency is the capability of releasing ammonia from the water. By applying a high salinity strategy, this study provides a prompt approach for removing high ammonia levels and relieving its adverse impacts on common carp. The study investigated five groups with triplicates where the control was kept with fresh water, and the remaining four groups stressed with different salinity levels (5, 10, 15, and 20 ppt) for 8 weeks. Then fish were exposed to unionized ammonia (NH3 ) stress (0.5 ppm) for 6 h. The final weight (FBW) and weight gain (WG) showed lower values in fish stressed with 15 and 20 ppt salinity levels than fish reared in 0 and 5 ppt salinity levels (p < 0.05). The lowest FBW and WG and the highest feed conversion ratio were shown in fish grown in 20 ppt (p < 0.05). The survival rate was markedly lowered by 15 and 20 ppt salinity levels (p < 0.05), while no significant differences were observed among 0, 5, and 10 ppt salinity levels (p > 0.05). Liver condition-related indices (alanine aminotransferase, aspartate aminotransferase, and alanine aminotransferase) were markedly increased in fish grown in 15 and 20 ppt before or after ammonia stress (p < 0.05). The results showed higher creatinine levels in fish raised in 15 and 20 ppt than the remaining salinity levels, with the highest value in fish of 20 ppt salinity before and after ammonia stress (p < 0.05). Markedly the blood glucose and cortisol levels were upraised in fish reared in 10, 15, and 20 ppt before and after ammonia stress (p < 0.05). The glucose level was not significantly different in fish reared in 5 ppt than 0 and 10 ppt salinity levels (p < 0.05). Generally, the blood glucose and cortisol levels were decreased markedly after ammonia stress than before ammonia stress (p < 0.05). Interestingly, total protein, albumin, and globulin levels were increased in common carp reared in different salinity levels after ammonia stress (p < 0.05). In conclusion, ammonia toxicity combined with high salinity resulted in a regulatory effect on the hepato-renal function and stress-related markers in common carp.

Water energy food nexus model: an integrated aqua-agriculture system to produce tilapia and sweet basil using desalinated water.

Under the framework of Water-Energy-Food Nexus, this study investigates the integration of solar-powered desalination with aquaculture and agriculture production systems to grow crops. Brackish water desalination is performed using reverse osmosis (RO), the permeate is directed to an aquaculture unit, and the fish effluent is used as irrigation water for crops. The experiment followed a split-plot design with three main variants: a full irrigation schedule for the basil plants with fish effluents as fertilizers, irrigation as fertigation with chemical fertilizers, and a mixed treatment of effluents and chemical fertilizers at 50% application each. Each treatment was further sprayed with or without foliar nutrient application. RO results gave a permeate recovery of 22%, and a salt rejection of 98.7%. In the aquaculture unit, tilapia harvest weight was 0.458 kg with a survival rate of 97.7% and harvest yield of 25 kg/ m3 of water. Effluent treatment exhibited the highest branching and plant height irrespective of the cut number, reaching 17.7 branches and 62-cm height. The effluent treatment under foliar application recorded the highest fresh and dry weights of basil with 14.7 ton/ha and 4.7 ton/ha, respectively. Effluent irrigation plus foliar application recorded basil yield of 5 kg/m3 effluent water. The dominant essential oil elements were linalool (55.5-61.6%), tau.-cadinol (5.3-8.3%), eucalyptol (5.4-7.7%), eugenol (2-6.8%), and (Z,E)-.alpha.-farnesene (3-5.2%). The study is among the very few integrated systems and, in particular, the current study is the first-time investigation of an integrated desalination, aquaculture, and agriculture production using renewable energy. Therefore, results suggest that integrating desalination, aquaculture, and agriculture could be a potential solution for the global water, energy, and food challenges.

A sandponics comparative study investigating different sand media based integrated aqua vegeculture systems using desalinated water.

This study investigated the utilization of fish effluents as irrigation water and nutrient sources to close the crop yield gap and increase Swiss chard productivity in a closed-loop sandponics system. The experiment was operated using desalinated water from a Reverse Osmosis plant. The study followed a completely randomized design with four variants, i.e., an aquaponic system (T1) and three sandponics systems; October (T2), Benu Suef (T3) and Fayoum (T4). Results indicated that T2 and T4 significantly recorded the highest plant heights in all cuts. The number of leaves per plant decreased with the increase in cut number. Leaf area and chlorophyll was significantly different between the treatments. T1 significantly had low biomass yields in cuts one and two, almost 40% less than T3 and T4. The various systems efficiently minimized water consumption ranging from 1.5 to 1.96 L/m2/day. The crop protein content ranged from 11.84 to 18.72 mg/100 g dry weight. Mineral composition in cut one was significantly higher compared to cuts two and three. The study recommends a novel technique for increasing crop production using fish effluents under sandponics systems while increasing water and fertilizer efficiency to close the crop yield gap.

Novel organic draw solution in forward osmosis process for fertigation: performance evaluation and flux prediction.

Fertilizer-drawn forward osmosis (FDFO) has received a lot of attention for its potential for producing fertigated water for agriculture purposes. To minimize the use of chemical-based fertilizers and support sustainable organic agriculture, this work investigated the separation performance of FO membrane for different feed concentrations (FS) of brackish water using microalgae Spirulina platensis as an organic fertilizer draw solution (DS). Different feed solution concentrations were investigated ranging 3-20 g/L NaCl, with various draw solutions of spirulina ranging 280-440 g/L. The performance was measured by water flux and recovery. The results showed that using spirulina as a draw solution is a promising solution for fertigation purposes. The results showed that Na+ in feed solution is concentrated by 41%, Cl- by 36%, and spirulina is diluted by 20% for feed salinity 5000 mg/L. The highest flux obtained with different feed solution 3000/5000/10,000/20,000 mg/L were 9/6/4.5/7 for draw solution concentration of 360/360/400/420 g/L. The calculated specific reverse solute flux (SRSF) JS/JW varies from 0.1 and 0.8 for different explored FS/DS concentrations. Flux decline and the down-time was investigated for the highest flux observed, showing 290 min of operation before cleaning action is required.

Blood biochemical variables, antioxidative status, and histological features of intestinal, gill, and liver tissues of African catfish (Clarias gariepinus) exposed to high salinity and high-temperature stress.

African catfish is a freshwater species with a high ability to resist brackish water conditions, but heat stress may impair the health status of fish. Thus, the impact of varying levels of water salinity (0, 4, 8, and 12 ppt) was investigated on the growth performance, survival rate, and blood biochemistry of African catfish (average weight: 180.58 ± 2.8 g and average length: 38 ± 1.2 cm) for 4 weeks; then, fish were stressed with high temperature (32 °C) for 72 h. The growth performance and survival rate were markedly higher in fish reared in 0, 4, and 8 ppt than fish in 12 ppt (p < 0.05). Before heat stress, the superoxide dismutase (SOD), catalase (CAT), glutathione (GSH) activities, and malondialdehyde (MDA) levels were markedly increased in fish stressed with 12-ppt salinity (p < 0.05). After heat stress, all groups showed a marked increased SOD, CAT, GSH, and MDA levels than fish before heat stress in the same manner (p < 0.05). Furthermore, fish in the 12 ppt group showed severe intestinal, gill, and liver histological features. The levels of blood glucose and cortisol were markedly increased in fish exposed with 8 and 12 ppt than 0 ppt gradually either before or after heat stress (p < 0.05). The highest values of ALT, AST, urea, creatinine, and the lowest total protein, albumin, and globulin were observed in fish reared in 12 ppt. Significant salinity and heat stress interactions were seen on the ALT, AST, urea, creatinine, total protein, albumin, and globulin values (p < 0.05). The integrated multi-biomarker response (IBR) results showed marked differences among the groups and increased gradually before and after heat stress, with the highest IBR in 12 ppt. In conclusion, growing African catfish in high salinity (12 ppt) hampered the growth performance and health status while the heat stress improved the antioxidative status vis-a-vis increased lipid peroxidation along with higher stress-related markers in expressed both blood and tissue.

Investigating the performance of hydroponic nutrient solutions as potential draw solutions for fertilizer drawn forward osmosis.

This research project aims at investigating the performance of hydroponic nutrient solutions as draw solutions for desalination using the fertilizer drawn forward osmosis (FDFO) process. Six different lettuce and leafy greens hydroponic nutrient stock solutions were prepared according to the literature and used in this study and tested on a bench-scale forward osmosis unit as draw solutions for the process. The feed solution for the process was deionized water mixed with NaCl in different concentrations, to represent different salinities of brackish groundwater. The draw efficiency of each solution was measured based on water flux, specific reverse solute flux, water recovery, and salt rejection. It was concluded that of the six tested nutrient solutions, the "Resh Florida, California" solution is the recommended solution to be used as draw solution for fertilizer drawn forward osmosis, due to its high performance in terms of water recovery (15.75%), flux (11 L/m2/h), salt rejection (92%), and SRSF (highest recorded SRSF for a specific ion (SO42-) was 7.3 g/L), as well as its low cost, relative to the other highly performing draw solution "Chekli" ($1.07/L vs. $3.73/L).

The antioxidant responses of gills, intestines and livers and blood immunity of common carp (Cyprinus carpio) exposed to salinity and temperature stressors.

Aquaculture activity is affected by various environmental factors, including water salinity and high temperatures. The present study investigated the impact of using varying water salinity (0, 5, 10, 15 and 20 ppt) on the growth behavior, immune responses and antioxidative responses of common carp. Fish were raised under optimal conditions except for water salinity for 8 weeks; fish were then subjected to high-temperature stress (32 °C) for 48 h. The results indicated a reduced final weight (FBW), weight gain (WG), specific growth rate (SGR), condition factor (CF), feed intake and feed efficiency ratio (FER) in common carp reared in 15 and 20 ppt (p < 0.05). The lowest FBW, WG, SGR, CF, feed intake and FER values were observed in fish reared in 20 ppt water salinity (p < 0.05). In gills, the superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GPx) were markedly decreased, but malondialdehyde (MDA) levels increased in fish challenged with 15 and 20 ppt before they were subjected to heat stress (p < 0.05). After heat stress, the SOD, CAT and GPx were decreased, and the MDA increased in fish reared in varying salinity levels (p < 0.05). Before heat stress, the intestinal SOD, CAT and GPx markers were decreased by 15 and 20 ppt, while the MDA level was increased by 15 and 20 ppt (p < 0.05). Generally, heat stress lowered the SOD, CAT and GPx activity in the intestines and liver tissues but increased MDA levels in common carp stressed by varying salinity levels (p < 0.05). The most decreased lysozyme activity, SOD, CAT and GPx and increased MDA levels were observed in common carp exposed to 20 ppt before and after heat stress (p < 0.05). After heat stress, fish exposed to 15 and 20 ppt had lower NBT than the remaining groups, and fish exposed to 20 ppt had the lowest values (p < 0.05). Overall, the heat stress markedly suppressed the antioxidant and immune responses of common carp reared in hypersalinity conditions.

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

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

The Role of Zinc Microelement in Aquaculture: a Review.

Trace elements are required in optimum regimes for improving the productivity and wellbeing of aquatic animals. Zinc is one of the main microelements involved in several functions in the animal's body. Zinc potentiates the metabolism function, synthesis of essential enzymes, and the formation of hormones associated with growth, reproduction, immunity, and antioxidative roles in aquatic animals. Several sources of zinc are regularly applied in aquaculture, including inorganic, organic, and nanoparticles. Many studies examined the effects of zinc supplementation in the diets of aquatic animals. The results indicated that zinc could be included in aquafeed in a dose-dependent manner. The effects of zinc depend on the dose, source, duration of feeding, animals' sizes, and experimental conditions. This article comprehensively discusses the results of relevant studies that investigated the effects of zinc on the performances of aquatic animals. The review also intended to update the academia with the previous and current status of using zinc in aquafeed. Furthermore, the article includes up-to-date outputs of relevant studies of using different zinc sources in aquafeed.

Updating the Role of Probiotics, Prebiotics, and Synbiotics for Tilapia Aquaculture as Leading Candidates for Food Sustainability: a Review.

Tilapia production has significantly increased over the past few years due to the adoption of semi-intensive and intensive aquaculture technologies. However, these farming systems have subjected the fish to stressful conditions that suppress their immunity, hence exposing them to various pathogens. The application of antibiotics and therapeutics to enhance disease resistance, survival, and growth performance in aquaculture has been recently banned due to the emergence of antibiotic-resistant bacteria that pose a serious threat to the environment and consumers of aquatic organisms. Hence, the need for an alternative approach based on sustainable farming practices is warranted. Probiotic, prebiotic, and synbiotic use in tilapia production is considered a viable, safe, and environmentally friendly alternative that enhances growth performance, feed utilization, immunity, disease resistance, and fish survival against pathogens and environmental stress. Their inclusion in fish diets and or rearing water improves the general wellbeing of fish. Hence, this review aims at presenting research findings from the use of probiotics, prebiotics, and synbiotics and their effect on survival, growth, growth performance, gut morphology, microbial abundance, enzyme production, immunity, and disease resistance in tilapia aquaculture, while highlighting several hematological, blood biochemical parameters, and omics techniques that have been used to assess fish health. Furthermore, gaps in existing knowledge are addressed and future research studies have been recommended.

Dietary Guduchi (Tinospora cordifolia) enhanced the growth performance, antioxidative capacity, immune response and ameliorated stress-related markers induced by hypoxia stress in Nile tilapia (Oreochromis niloticus).

Nile tilapia can tolerate a wide range of farming conditions; however, fluctuations in the environmental conditions may impair their health status. The incorporation of medicinal herbs in aquafeed is suggested to overcome stressful conditions. In this study, dietary Guduchi (Tinospora cordifolia) was evaluated on the growth performance, antioxidative capacity, immune response, and resistance of Nile tilapia against hypoxia stress. Fish fed five diets incorporated with Guduchi at 0, 2, 4, 6, and 8 g/kg for 56 days then exposed with hypoxia stress for 72 h. The growth performance, feed intake, and feed efficiency ratio were significantly (P < 0.05) increased by including Guduchi in tilapia diets regardless of the inclusion level. Similarly, the lipase and protease activities were markedly (P < 0.05) increased in tilapia fed dietary Guduchi. The activities of lysozyme and bactericidal activities in serum and mucus, nitro-blue tetrazolium (NBT), and alternative complement activity (ACH50) were markedly (P < 0.05) enhanced in tilapia treated with Guduchi supplements regardless of the dose. Additionally, the activities of liver and intestinal superoxide dismutase, catalase, and glutathione peroxidase were markedly enhanced (P < 0.05) by including Guduchi in tilapia diets compared with the control. Before and after hypoxia stress, tilapia-fed dietary Guduchi had lower glucose and cortisol levels than fish-fed Guduchi-free diets (P < 0.05). In all groups, glucose and cortisol levels were markedly higher after hypoxia compared before hypoxia stress (P < 0.05). In conclusion, dietary Guduchi can be included at 5.17-5.49 g/kg to enhance the growth performance, digestive enzyme activity, immune and antioxidative responses, and the resistance of Nile tilapia against hypoxia stress.

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

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

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

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

Dietary Cinnamon Successfully Enhanced the Growth Performance, Growth Hormone, Antibacterial Capacity, and Immunity of European Sea Bass (Dicentrarchus labrax).

Dietary cinnamon has several bioactive compounds with growth-promoting and immunomodulation potential and is suggested for finfish species. This study evaluated the inclusion of cinnamon at 0, 10, 15, and 20 g/kg in European sea bass (Dicentrarchus labrax) diets. After 90 days, the highest final weight, weight gain, specific growth rate, protein efficiency ratio, and the lowest feed conversion ratio were seen in fish treated with 10 g/kg (p < 0.05). Further, the measured growth hormone in the blood indicated that fish treated with 10 g/kg had a higher level than fish 0 and 20 g/kg. After the feeding trial, fish treated with cinnamon at varying levels had higher lipid content than fish before the feeding trial (p < 0.05). Lower Vibrio spp. and Faecal Coliform counts were observed in fish treated with cinnamon than fish fed a cinnamon-free diet (p < 0.05). The hematocrit level was markedly (p < 0.05) increased in fish fed cinnamon at 10 g/kg compared to the control without significant differences with fish fed 15 and 20 g/kg. Hemoglobin was significantly increased in fish treated with cinnamon at 10, 15, and 20 g/kg compared to fish fed a cinnamon-free diet (p < 0.05). Red and white blood cells (RBCs and WBCs) were meaningfully (p < 0.05) increased in fish treated with cinnamon compared with the control. Markedly, fish treated with cinnamon had higher serum total lipids than the control with the highest value in fish treated with 15 g/kg (p < 0.05). The lysozyme activity was markedly higher in fish treated with 15 g cinnamon/kg than fish fed 0, 10, and 20 g/kg (p < 0.05). Moreover, phagocytic activity was significantly higher in fish treated with cinnamon at 10, and 15 g/kg than fish fed 0 and 20 g/kg (p < 0.05). In conclusion, dietary cinnamon is suggested at 10-15 g/kg for achieving the high production and wellbeing of European sea bass.