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The study was conducted to evaluate the effect of Moringa olifera on the growth and gut health of Tilapia (Oreochromis niloticus). The feed having 30% crude protein was prepared as an experimental diet with 4%, 8% and 10% M. olifera leaf supplementation, respectively. The control diet was devoid of M. olifera leaves. The 10 weeks feeding trial was carried out on 60 fish in aquaria. Fish was fed @ 3% of body weight twice a day. Diet with the high level of inclusion of M. olifera leaves significantly increased the growth rate, Survival Rate (SR), Specific Growth Rate (SGR) and Feed Conversion Efficiency (FCE) in all treatment groups compared to the control group. Similarly, Feed Conversion Ratio (FCR) gradually decreased and found highly-significant. To check the gut health of the Tilapia, random samples were selected and dissected. Nutrient agar was used as culture media to check the growth of bacteria. Pour Plate Method was used for viable colonies count by colony counter. Through staining method, the different bacteria such as Escherichia coli, Salmonella, Shigella and Pseudomonas aeruginosa were identify abundantly in the intestine of control diet fish but less number present in treatment diets groups. These results showed that M. olifera leaves up to 10% of dietary protein can be used for Nile tilapia for significant growth and healthy gut microbiota of fish. Resumo O estudo foi conduzido para avaliar o efeito da Moringa olifera no crescimento e saúde intestinal da tilápia (Oreochromis niloticus). A ração com 30% de proteína bruta foi preparada como dieta experimental com 4%, 8% e 10% de suplementação de folhas de M. olifera, respectivamente. A dieta controle foi desprovida de folhas de M. olifera. O ensaio de alimentação de 10 semanas foi realizado em 60 peixes em aquários. O peixe pesava 3% do peso corporal duas vezes ao dia. A dieta com alto nível de inclusão de folhas de M. olifera aumentou significativamente a taxa de crescimento, taxa de sobrevivência (SR), taxa de crescimento de sobrevivência (SGR) e eficiência de conversão alimentar (FCE) em todos os grupos de tratamento em comparação com o grupo de controle. Da mesma forma, a taxa de conversão de alimentação (FCR) diminuiu gradualmente e foi considerada altamente significativa. Para verificar a saúde intestinal da tilápia, amostras aleatórias foram selecionadas e dissecadas. O ágar nutriente foi usado como meio de cultura para verificar o crescimento das bactérias. O método da placa de Verter foi usado para a contagem de colônias viáveis por contador de colônias. Através do método de coloração, diferentes como Escherichia coli, Salmonella, Shigella e Pseudomonas aeruginosa foram identificados abundantemente no intestino de peixes da dieta controle, mas em menor número nos grupos de dieta de tratamento. Esses resultados mostraram que M. olifera deixa até 10% da proteína dietética e pode ser usado para tilápia do Nilo para um crescimento significativo e microbiota intestinal saudável de peixes.

Light is an essential natural factor of fish growth and development. A light regime in indoor aquaculture is critical for sustainable fish production. This research aimed to investigate the effect of light intensity and photoperiod on the growth performance and stress response of Nile tilapia (Oreochromis niloticus), which is an important commercial species, in a recirculating aquaculture system (RAS). Fingerlings with an average weight of 5 ± 0.9 g were randomly assigned to nine 1.5 m3 tanks with 145 fish in each tank, cultured under different light intensities (1000, 2000, and 3000 lx) and photoperiods (12L:12D, 18L:6D, 24L:0D), and fed to apparent satiation twice a day for 160 days. The growth of tilapia subjected to 2000 lx was significantly better than that exposed to 1000 and 3000 lx (P 0.05). Light intensity and photoperiod manipulation did not cause a significant chronic stress response in tilapia. This study demonstrated that light intensity, especially at 2000 lx, and photoperiod manipulation could stimulate the growth of tilapia in the RAS and significantly affect economic profitability. This study also served as an important reference for tilapia indoor aquaculture.

Establishing suitable salt tolerant all-male tilapia strains with fast growth rate is a crucial requirement for successful euryhaline farming required for controlling prolific breeding and as an adaptation to the effect of climate-induced drought. This study assessed the percentage of tilapia male hybrids, their growth performance and survival rate produced by crossing female Nile tilapia (Oreochromis niloticus) and male Rufiji tilapia (Oreochromis urolepis urolepis) at different salinities. The fingerlings were reared for 70 days in triplicate concrete tanks (1 m3), each stocked with 15 fish weighing 1.62 ± 0.03 g, 1.69 ± 0.02 g and 1.41 ± 0.06 g exposed to 2, 15 and 35 ppt salinities, respectively. Acclimatization was done by adding seawater to freshwater at a rate of 2 ppt per day for 18 days. Fish sexing was done by visual assessment of the genital papilla followed by rearing the hybrids for six months to observe reproduction. Results showed that, the cross between O. niloticus (female) and O. urolepis urolepis (male) produced hybrids that were all-males without any reproduction within six months post hybridization. The hybrids reared at a salinity of 2 ppt had higher growth performance than those reared at 15 and 35 ppt. Similarly, hybrids cultured at 15 ppt had significantly higher growth performance than those reared at 35 ppt. All the hybrids produced had survival rates of 100%. This study indicated that, all-male tilapia produced by crossing between O. niloticus (female) and O. urolepis (male) can be used by fish farmers as alternative species for mariculture development to control prolific breeding and as an adaptation strategy to climate change.

A 56-day experiment was conducted to investigate the effects of ambient salinity and alkalinity on fatty acids, free amino acids and related anabolic metabolisms of Nile tilapia. The fatty acid and free amino acid contents in the muscle of tilapia cultured in saline water (SW), alkaline water (AW), saline–alkaline water (SAW) and fresh water (FW) conditions were analyzed and compared. The mRNA levels and enzymatic activities of fatty acyl desaturase (FADS2), elongation of very long-chain fatty acids (ELOVL5), Δ1-pyrroline-5-carboxylate synthase (P5CS), ornithine-δ-aminotransferase (δ-OAT), and proline dehydrogenase (PDH) were also determined. The contents of saturated and monounsaturated fatty acids were significantly higher in the AW and SAW groups than those in the SW group, and those of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) were the highest in the SAW group. The contents of flavor amino acids in the SAW and AW groups were significantly higher than that in the SW group, and that of proline in the SW, AW, and SAW groups was 3.58-, 4.11-, and 4.15-times higher than that in the FW group. The mRNA levels and enzyme activities of FADS 2, ELOVL5, PDH and P5CS were found to differ among the different groups. The results suggested that ambient salinity and alkalinity could effectively improve flesh quality of tilapia by regulating lipid and proline metabolism pathways.

Spermatogenesis is a complex process in which spermatogonial stem cells differentiate and develop into mature spermatozoa. The transcriptional regulatory network involved in fish spermatogenesis remains poorly understood. Here, we demonstrate in Nile tilapia that the Sox transcription factor family member Sox30 is specifically expressed in the testes and mainly localizes to spermatocytes and spermatids. CRISPR/Cas9-mediated sox30 mutation results in abnormal spermiogenesis, reduction of sperm motility, and male subfertility. Comparative transcriptome analysis shows that sox30 mutation alters the expression of genes involved in spermatogenesis. Further chromatin immunoprecipitation followed by high-throughput sequencing (ChIP-seq), ChIP-PCR, and luciferase reporter assays revealed that Sox30 positively regulates the transcription of ift140 and ptprb, two genes involved in spermiogenesis, by directly binding to their promoters. Our data, taken together, indicate that Sox30 plays an essential role in Nile tilapia spermatogenesis by directly regulating the transcription of the spermiogenesis-related genes ift140 and ptprb.

Urbanization and industrialization have led to heavy metals in aquatic environments. These metals are toxic, nondegradable, and persistent. Lead (Pb) is an immunotoxicant that can adversely affect animal health, even at low levels. Chitosan (CHI) is an eco-friendly compound with exceptional antibacterial and immunostimulant characteristics. This study investigated the effect of dietary CHI on the antioxidant defense system and innate immune responses of tilapia (Oreochromis niloticus) against the cytotoxic effect of prolonged Pb exposure. The results indicated dietary CHI could nullify the toxicity of prolonged Pb exposure in fish by substantially activating the antioxidant defense system capacity and fish innate immune responses. In addition, CHI minimized the alterations in the histology of fish organs. The findings suggest that chitosan can be a commercial, eco-friendly immunostimulant and bioactive compound for mitigating the effects of heavy metal toxicity in aquaculture.

Aquaponics is a fish-plant recirculating system where nutrients received from the fish culture are absorbed by the plants for growth. The technology is relatively new for fish culture in Kenya, and the principles and operations remain largely untested for many fish species. This study determined how stocking density affects the growth performance and water quality in a Nile tilapia-lettuce (Lactuca sativa) aquaponics system. The experimental design included five replicates for each of the aquaponic systems stocked at densities of 150, 300, and 450 fish/m3 for a rearing period of 56 days. Each treatment had a planting density of 16 lettuce/m2. The water quality parameters ranges during the rearing period were 3.83–5.35 mg/L for dissolved oxygen, 7.44 to 7.6 for pH, 0.014 mg/L to 0.032 mg/L for total ammonium nitrate (TAN), 1.11–1.34 mg/L for nitrate, and 0.01–0.08 mg/L for nitrite, and all decreased with increasing stocking density. The final weight of fingerlings was 25.2 ± 4.2 g, 32.0 ± 3.8 g and 42.6 ± 3.1 g for 450, 300, and 150 fish/m3 respectively. Specific growth rate (SGR) was reduced with increasing stocking density whereas food conversion ratio (FCR) increased with stocking density. Aquaponic systems with the lowest stocking densities performed better than 300 and 450 fish/m3 respectively.

The accumulation potency of zinc nanoparticles in Nile tilapia (Oreochromis niloticus) was previously studied but their impacts on proximate chemical composition in muscle tissue by describing the dose-dependent accumulation and the protective role of vitamins (E + C), have not been investigated. Therefore, this study was carried out to assess the protective role of vitamins (E + C) on Zn accumulation in muscle and gill tissues of O. niloticus exposed to three sub-lethal concentrations (1/8 LC50, 1/4 LC50, and 1/2 LC50) of zinc oxide nanoparticles (ZnO NPs) compared to zinc oxide bulk particles (ZnO BPs) as well as their effects on the induced chemical composition alterations for different experimental periods (7, 14, 21, and 28 days). The data displayed that fish exposed to the different sub-lethal concentrations of ZnO NPs or ZnO BPs have a significant increase (PO. niloticus fish.

The Nile tilapia, Oreochromis niloticus, GIFT strain is suggested to be a good candidate for culture in brackish water. Gill is regarded as the dominate site of osmo-regulation. Recently, the mechanisms underlying salinity challenge in gill of tilapia are getting increasing attention. In this study, an integrated analysis of metabolomics and transcriptomics on gill of GIFT tilapia under salinity 17 and 27 challenge for three and a half months are conducted. 1164 DEGs in the comparison 0 vs 17 and 910 DEGs in the comparison 0 vs 27 are identified. Many typical genes involved in osmo-regulation are found, including calcium/calmodulin-dependent protein kinase II beta 1, Aquaporin 3, Potassium channel subfamily K member, chloride channel 2, Solute Carrier Family 12 Member 8, Solute Carrier Family 12 Member 2, Na +/K + ATPase. Some biosynthesis, metabolism, energy or transport related pathways are over-represented, such as Synthesis of UDP-N-acetyl-glucosamine, Synthesis of substrates in N-glycan biosynthesis, Biosynthesis of DPAn-3 SPMs, Metabolism of lipids, Gluconeogenesis and SLC-mediated transmembrane transport. In addition, totally 23 metabolites are significantly responded in gill under salinity challenge. Of which, 11 metabolites including 12-Hydroxyeicosatetraenoic acid and choline are significantly down-regulated and 8 metabolites including adenine, Lys-Pro, inosine are significantly up-regulated under salinity challenge. Our study provides an important database for further functional analysis of osmo-regulation in gill of Nile tilapia.

The cladocera Moina macrocopa serves as a common live feed that is suitable for most freshwater fish species. Seven diets for the cladocera, viz. Chlorella sp., rice bran, soybean meal, chicken manure, swiftlet waste, canola oil, and artificial micro pellet were compared in this study. This study's objective was to analyse the effect of enriched M. macrocopa on the growth, survival, and dietary profiles of hybrid Nile tilapia fry. The feeding experiment lasted for over 60 days. The M. macrocopa enriched with rice bran has produced the highest weight gain (5.83 g), survival (86.67%), protein (24.88%), and lipid (6.85%) in Nile tilapia fry. While, fatty acid such as α-linolenic acid (ALA; 4.67%) was found to be the highest in fry fed with M. macrocopa enriched with soybean meal. Arachidonic acid (ARA; 3.69%) and docosahexaenoic acid (DHA; 0.47%) were the highest in tilapia fry fed with M. macrocopa enriched with rice bran, while eicosapentaenoic acid (EPA; 6.33%) was the highest in tilapia fry fed with M. macrocopa enriched with Chlorella sp. In conclusion, the manipulation of nutrient such as protein, lipid and fatty acid Scompositions in M. macrocopa diet has successfully improved the nutrient compositions and production of Moina sp. culture that indirectly increased the growth and survival of hybrid tilapia fry.

Pathogens isolated from fish appear to possess considerable antimicrobial resistance and represent a problem for the economy and public health. Natural antimicrobial substitutes to traditional antibiotics represent an essential tool in the fight against antibiotic resistance. Nanotechnology has shown considerable potential in different research fields, and the antimicrobial properties of silver nanoparticles are known. Silver has been used for medical purposes since ancient times because of its bactericidal properties, and the highly reactive surfaces of silver nanoparticles (AgNPs) indicate that they might have a function in antimicrobial applications. This work aimed to study the antimicrobial properties of biologically produced AgNPs from Origanum vulgare leaves compared to chemically produced AgNPs. Both types were characterized by UV-vis spectrophotometry, TEM, and dynamic light scattering and tested against three bacterial strains (Streptococcus agalactiae, and Aeromonas hydrophila, both isolated from Nile tilapia and Vibrio alginolyticus, isolated from sea bass) and three fungal strains (Aspergillus flavus, Fusarium moniliforme, and Candida albicans, all isolated from Nile tilapia). Disk diffusion test and evaluation of ultrastructure changes of tested microorganisms treated with AgNPs by transmission electron microscopy were performed. Moreover, the hemolytic properties of AgNPs were studied on chicken and goat red blood cells. The results obtained declare that the green biological production of silver nanoparticles is safer and more effective than the chemical one; moreover, AgNPs have interesting dose-dependent antimicrobial properties, with better results for biologically produced ones; their effectiveness against tested bacterial and fungal strains opens the way to their use to limit fish diseases, increase economy and improve human health.

The acute toxicity of household detergent (Ariel) on blood parameters and histology of Oreochromis niloticus was investigated using static bioassay for 96 h. Linear alkylbenzene sulfonate (LAS) is an anionic surfactant widely used in detergents and cleaners, both in industrial and household applications. LAS contaminating aquatic ecosystems as a potential toxic pollutant, was investigated in the present study for acute toxicity. The fish samples were divided into six groups, including 20 fish in each group. Normal feed was given to control group without detergents treatment. Hematological parameters (RBC count, Hb, Ht and platelets) were significantly declined, while WBC count showed a highly significant increase. Compared with the control group, significant elevation of serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) was recorded in fish treated with different concentrations of detergent. Catalase (CAT), Superoxide dismutase (SOD) activities and Reduced Glutathione (GSH) concentration showed a highly significant reduction. Total proteins showed significant decrease, while total lipids, cholesterol and triglycerides significantly increased. The mean lethal concentration (LC50) for 96 h of Ariel was at concentration 10 mg/L. Relative percentage of detergent residues in fish muscles was increased with higher detergent concentrations. In conclusion, exposure to detergents resulted in great alterations in the histological structure of liver and gills.

This study evaluates how white mulberry (Morus alba L.) leaf extracts affect the growth, antioxidant activity, and immune response in Nile tilapia Oreochromis niloticus. Mulberry leaf extracts were obtained through aqueous extraction (AE) and ethanol extraction (EE). Powder of mulberry leaf (PML) was added directly to feed and compared with the effects of feeds supplemented with the different extracts. Fish were divided into eight groups for an 8-week feeding trial where they were fed the basal diet or supplemented with 10% PML, 10% AE, 20% AE, 40% AE, 10% EE, 20% EE, or 40% EE. The inclusion of mulberry leaf extract obtained with either method showed better effects on fish growth performance, antioxidant activities and acid phosphatase activity (ACP) in serum, immune cytokine expression, and intestinal morphology as compared with controls or fish fed the 10% PML diet. The specific growth rate was significantly higher in the 10% AE, 10% EE, and 20% EE groups compared with all other groups (P

The study was executed to find out the potential effects spent coffee ground (SCG) on Nile tilapia's skin mucosal and serum immunities, disease prevention, and growth rate reared in a biofloc system. Nile tilapia fingerlings (average weight 15.25 ± 0.07 g) were disseminated into 15 aquaria (150 L tank−1) at a density of 20 fish per aquarium and treated five diets: SCG1 (control), SCG2 (10 g kg−1), SCG3 (20 g kg−1), SCG4 (40 g kg−1), and SCG5 (80 g kg−1) for eight weeks. A Completely Randomized Design (CRD) with three replications was applied. Growth rate, skin mucus, and serum immunities were quantified every 4 weeks; whereas the challenge study was conducted at the termination of the feeding trial. The outputs indicated that dietary incorporation of SCG give rise to the enhancement of SGR and FCR in comparison with the control, with best levels noted in fish fed SCG2 diet. Similarly, significant enhancements in skin mucosal and serum immunities were revealed in fish treated SCG2 over the control and other SCG diets. Likewise, higher survival rates against Streptococcus agalactiae were displayed in fish fed SCG, with the maximum level displayed in the fish treated SCG2. In conclusion, dietary supplementation of SCG2 (10 g kg−1) can be potential used as immunostimulants in tilapia aquaculture.

This study was conducted to estimate the apparent digestibility coefficients (ADC) of the nutrients and energy contained in banana peel, cassava peel, cocoa husk, copra waste, and sugarcane bagasse in GIFT Nile tilapia (initial body weight 22.38 ± 0.33 g). A reference diet was formulated to satisfy the nutrient requirement of the fish. Five test diets were formulated to contain 70% of the reference diet and 30% of each test ingredient. The experiment lasted 42 days. The ADCs of dry matter (DM), crude lipid (CL), ash, crude fiber (CF), total carbohydrate (TC), and gross energy (GE) were 16.19%, 6.56%, 11.40%, 38.98% and 15.68% for banana peel; the ADCs of DM, crude protein (CP), CL, ash, CF, TC, and GE were 69.11%, 31.61%, 61.07%, 68.88%, 73.14%, 71.24%, and 69.00% for cassava peel; the ADCs of DM, ash, CF, TC, and GE were 10.56%, 0.84%, 28.70%, 2.82%, and 8.459.69% for cocoa husk; the ADCs of DM, CP, CL, ash, CF, TC, and GE were 63.08%, 20.14%, 66.60%, 32.53%, 69.70%, 66.21%, and 64.06% for copra waste; and the ADCs of DM, CF, TC, and GE were 15.22%, 36.71%, 34.34%, and 15.55% for sugarcane bagasse in tilapia respectively. This experiment generated basic information for the use of these ingredients in diet formulation for tilapia. However, considering the relatively low ADCs of nutrients observed in the present experiment, further processing could be an interesting avenue in improving the nutritional value and digestibility of these ingredients.

Saudi journal of biological sciences 29(1), 190-196 (2022). doi:10.1016/j.sjbs.2021.08.072, Published by Elsevier, Amsterdam [u.a.]

Toll-like receptors (TLRs) are evolutionarily conserved proteins of pattern recognition receptors (PRRs) and play a crucial role in innate immune systems recognition of conserved pathogen-related molecular samples (PAMPs). We identified and characterized TLR18 from Nile tilapia (Oreochromis niloticus), OnTLR18, to elucidate its role in tissue expression patterns, modulation of gene expression after microbial challenge and TLR ligands, subcellular localization in fish and human cells, and the possible effectors TLR18 induces in a melanomacrophage-like cell line (tilapia head kidney (THK) cells). OnTLR18 expression was detected in all tissues examined, with the highest levels in the intestine and the lowest in the liver. OnTLR18 transcript was up-regulated in immune-related organs after bacterial and polyinosinic-polycytidylic acid (poly I:C) challenges and in the THK cells after lipopolysaccharide (LPS) stimulation. In transfected THK and human embryonic kidney (HEK) 293 cells, OnTLR18 localizes in the intracellular compartment. OnMyD88 and OnTRIF, but not OnTIRAP, were co-immunoprecipitated with OnTLR18, suggesting that the former two molecules are recruited by OnTLR18 as adaptors. The constitutively active form of OnTLR18 induced the production of pro-inflammatory cytokines, type I interferon (IFN), and antimicrobial peptides such as tumor necrosis factor α, interferon (IFN) d2.13, tilapia piscidin (TP)2, TP3, TP4, and hepcidin in THK cells. Our results suggest that OnTLR18 plays an important role in innate immunity through initiating nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) and IFN signaling pathways via OnMyD88 and OnTRIF and induces the production of various effectors in melanomacrophages.

Human population has continued to increase unabatedly with its attendant demands on food in order to ease the difficulties of malnutrition and starvation. This continuous rise in population has clearly indicated that the conventional forms of livestock production and captured fisheries will not be sufficient to solve the problem of high protein demands. Aquaculture remains the best option that can bridge the wide gap between human protein demands and domestic production through the culture of fish species like Nile Tilapia (Oreochromis niloticus).Oreochromis niloticusis one of the most cultured finfish, due to its acceptability as food, fast growth, availability for farmers, ability to breed in captivity, resistance to diseases and harsh environmental conditions. Despite all these outstanding characteristics, there is still high level of apathy in commercial production of Nile Tilapia, due to its precocious maturity and uncontrolled breeding, which results in overpopulation of ponds, stunted growth and low commercial value. To mitigate this challenge, the use of synthetic hormones such as 17α-methyl testosterone has been developed to masculinize female tilapia present in a pond, thereby allowing the production of marketable sized fish since the male grows faster than the female. Though, the use of synthetic hormones has helped in some ways, but the negative effects have necessitated farmers to seek alternatives that are environmental friendly and safe for consumers. Dietary phytochemicals have been established to be good alternatives and their use is now gaining global acceptance. Dietary phytochemicals are bioactive compounds commonly found in plant-based diets such as fruits, vegetables, grains and teas. Dietary phytochemicals when administered to newly hatched tilapia species, influences the undifferentiated gonadal tissue of generic females to develop testicular tissue, thus functioning reproductively as males. Some of these phytochemicals such as Flavonoids, Saponins, Phenolics and Alkaloids are found in plants likeCarica papayaseeds,Azadirachta indica, andMucuna pruriens. The usefulness of these phytochemicals is based on their ability to influence sex reversal inOreochromis niloticus, cost effect, easily accessible especially by small scale fish farmers, simple to apply, and being safe for both human and the environment since they are more biodegradable than synthetic hormones.

During the early stage of biological invasions, interactions occur between native and non-native species that do not share an evolutionary history. This can result in ecological naïveté, causing native species to exhibit maladaptive behavioural responses to novel enemies, leading to negative consequences for individual fitness and ecosystem function. The behavioural response of native to non-native species during novel encounters can determine the impact of non-native species, and restrict or facilitate their establishment. In this study we simulated novel encounters between a widespread invasive fish species, the Nile tilapia (Oreochromis niloticus), and a threatened native Manyara tilapia (Oreochromis amphimelas). In the first experiment single adult O. niloticus were presented with a stimulus chamber (a transparent plastic cylinder) which was empty during control trials and contained a pair of juvenile O. amphimelas in stimulus trials. In the second experiment, the reciprocal set up was used, with pairs of juvenile O. amphimelas as the focal species and adult O. niloticus as the stimulus. Both species approached the stimulus chamber more readily during stimulus trials, a behavioural response which would increase the prevalence of interspecific interactions in situ. This included physical aggression, observed from the competitively dominant O. niloticus towards O. amphimelas. Despite an initial lack of fear shown by O. amphimelas, close inspection of the stimulus chamber often resulted in an energetically costly dart response. Under field conditions we predict that naïve native individuals may readily approach O. niloticus, increasing the likelihood of interactions and exacerbating widely reported negative outcomes.

The current study was conducted in two different localities have been selected in Western Kordofan State (Elsonout and Abu-zabad Localities) to evaluate some heavy metals concentrations (Copper, Cadmium, Zinc, and Lead) in three parts (liver, gills and muscles) of Nile Tilapia (Oreochromis niloticus) cultured in Dams, also to evaluate the same heavy metals concentrations in Dams water where Nile Tilapia is cultured. The evaluation was included the correlation of heavy metals accumulation between fish organs and water samples were compared. Finally, the results were compared with recommended levels by FAO, WHO and other international organizations. A total of 54 samples has been taken from marketable size Nile Tilapia parts (gills; livers and muscles) and subjected to analysis of heavy metals accumulations. Also, a total of 18 water samples were taken from Dams (shallow, middle and deep water). The data was subjected to SPSS using ANOVA. The findings of this work were revealed that, there were a highly significant differences (P≤0.01) in all heavy metals among gills, liver and muscles of Nile Tilapia cultured in Dams. And there was a highly significant difference (P≤0.01) in all heavy metals among gills, liver and muscles of Nile Tilapia according to localities. Anyway, when compared fish organs; we found that, gills were recorded the maximum figures in all heavy metals followed by livers and the minimum figures were recorded by muscles. The results of this study were in the permissible levels recommended by international organizations.

Background and Aim: Industrial waste, such as heavy metals, is a major source of water pollution; at high levels, such pollution can reduce river water quality to the extent that it becomes unsuitable for aquaculture of freshwater fish. This study aimed to focus on the effects of copper (Cu) exposure in Nile tilapia (Oreochromis niloticus) and specifically the ability of Lactobacillus-based probiotics supplementation in fish feed to ameliorate damage to gonads and negative effects on red blood cells (RBCs), whole blood cells (WBCs), hematocrit (HCT) levels, hemoglobin (HGB) levels, and malondialdehyde (MDA) levels following such exposure. Materials and Methods: Thirty-two Nile tilapia fish were divided into eight groups: A negative control (without probiotics or Cu), a positive control (with probiotics but without Cu), three treatments with probiotics in feed, and one of three Cu concentrations (0.75, 1.50, or 3.00 mg/L), and three treatments with these three Cu concentrations but without probiotics in feed. The probiotics concentration in feed was 25 mL/kg (1×108 CFU/mL). Feeding was for 15 days, after which the hematological parameters, gonadal (testis) structure, and MDA levels of fish were analyzed. Results: Exposure to Cu significantly (p

Water reuse in fish farming is a practice that has been spreading significantly, therefore requiring more efficient and vigorous treatment systems. The objective of this study was to evaluate the potential reuse of aquaculture wastewater after being treated in horizontal subsurface flow constructed wetlands (HSSF-CW). Three HSSF-CWs with dimensions of 1.0 m in width, 3.0 m in length, and 0.30 m in depth were evaluated. One HSSF-CW had stargrass (Cynodon nlemfuensis) cultivated; the other had cattail (Typha latifolia), and the third was used as a control, where there was no cultivation. The wastewater was provided from three Nile tilapia breeding tanks, which recirculated the entire system after going through the HSSF-CW. The following variables were determined every five days at the HSSF-CW influent and effluent: temperature, pH, turbidity, electrical conductivity, redox potential, dissolved oxygen, ammonium, and nitrate. The treatment in the HSSF-CW allowed the reuse of aquaculture wastewater as it provides water quality levels according to the recommendation for Nile tilapia breeding. Furthermore, the water quality parameters monitored in HSSF-CW effluent remained within limits established by CONAMA Resolution No. 357/2005 for aquaculture and fishing activity. Water reuse in fish farming is a practice that has been spreading significantly, therefore requiring more efficient and vigorous treatment systems. The objective of this study was to evaluate the potential reuse of aquaculture wastewater after being treated in horizontal subsurface flow constructed wetlands (HSSF-CW). Three HSSF-CWs with dimensions of 1.0 m in width, 3.0 m in length, and 0.30 m in depth were evaluated. One HSSF-CW had stargrass (Cynodon nlemfuensis) cultivated; the other had cattail (Typha latifolia), and the third was used as a control, where there was no cultivation. The wastewater was provided from three Nile tilapia breeding tanks, which recirculated the entire system after going through the HSSF-CW. The following variables were determined every five days at the HSSF-CW influent and effluent: temperature, pH, turbidity, electrical conductivity, redox potential, dissolved oxygen, ammonium, and nitrate. The treatment in the HSSF-CW allowed the reuse of aquaculture wastewater as it provides water quality levels according to the recommendation for Nile tilapia breeding. Furthermore, the water quality parameters monitored in HSSF-CW effluent remained within limits established by CONAMA Resolution No. 357/2005 for aquaculture and fishing activity.

Lead has long been known as neurotoxic and immunotoxic heavy metal in human and animals including fish, whereas, 2, 3-dimethylsuccinic acid (DMSA) and fulvic acid (FA) are well-known biological chelators. The present investigation was carried out to assess the potential chelating and antioxidant effects of dietary supplementation with DMSA and FA against lead acetate (Pb)-induced oxidative stress in Nile tilapia, O. niloticus. One-hundred and eighty apparently healthy O. niloticus fish (30 ± 2.5 g) were allocated into six equal groups. The first group was fed on basal diet and served as control, while the second group was fed on DMSA-supplemented basal diets at levels of 30 mg/kg diet; the third group was fed on FA-supplemented basal diet at level of 0.3 mg/kg diet; the forth, fifths, and sixth groups were exposed to 14.4 mg Pb /L water (1/10 LC50) and feed on basal diet only, basal diet supplemented with DMSA (0.3 mg/kg diet), or basal diet supplemented with FA (0.3 mg/kg diet), respectively. Antioxidant and lipid peroxidative status, activity of glucose 6-phosphate dehydrogenase (G6PD), and lactate dehydrogenase (LDH) as well as the histopathologic findings were evaluated in brain tissues, while the Pb residues were evaluated in liver, muscles, and brain tissues. The results of the present study showed that DMSA and FA decreased malondialdehyde (MDA) and Pb residue in tissues of Pb-exposed fish and improved the histologic picture and brain contents of glutathione (GSH), glutathione-s-transferase (GST), glutathione peroxidase (GPx), superoxide dismutase (SOD), catalase (CAT), G6PD, LDH, and total antioxidant capacity (TAC). It could be concluded that DMSA and FA supplementation exhibited potential neuroprotective effect against Pb-induced oxidative brain damages in O. niloticus through improvement of antioxidant status of the brain tissue.

Fish is perishable and has the short shelf-life. To maintain its quality, it is necessary to implement the appropriate technology, particularly nonthermal processing along with safe additive, especially from plant origin under the concept of "hurdle technology". The use of potential vesicle including liposome for loading the plant extract could be a means to enhance the stability and activities of the extract. The current study aimed to evaluate the effect of liposomes loaded with betel leaf ethanolic extract (L/BLEEs) or unencapsulated BLEE (U/BLEE) in conjunction with modified atmospheric packaging (MAP) and nonthermal plasma (NTP) on the quality changes and shelf-life of Nile tilapia fillets (TFs) stored under refrigerated condition (4°C). TFs treated with L/BLEE or U/BLEE at 400 ppm, packed under modified atmosphere (CO2 :Ar:O2 = 60:30:10) and subjected to NTP for 300 s (L/BLEE-400/MAP-NTP and U/BLEE-400/MAP-NTP, respectively) had the lowest microbial and chemical changes during storage, while the control showed the highest changes (p 0.05) between all the samples at day 0 of storage. Only L/BLEE-400/MAP-NTP and U/BLEE-400/MAP-NTP were still sensorially acceptable after 12 days at 4°C. Therefore, L/BLEE or U/BLEE combined with MAP/NTP treatment could be adopted as a potent hurdle for shelf-life extension of TFs. PRACTICAL APPLICATION: Natural additives and nonthermal processing technologies have gained increasing interest for preservation of fish. Liposomes loaded with betel leaf ethanolic extract (L/BLEE) rich in polyphenolics could be used together with modified atmospheric packaging (MAP) and nonthermal plasma (NTP) to retard bacterial growth and chemical deterioration in Nile tilapia fillets. These hurdles were proven to be able to maintain the qualities of tilapia fillets stored at 4°C up to 12 days, especially when L/BLEE was used at 400 ppm. Therefore, shelf-life extension of Nile tilapia fillets or other fish can be achieved by using the natural additive and nonthermal processing technologies.

The acute toxicity of the pesticides atrazine, mancozeb, chlorpyrifos and lambda-cyhalothrin, acting singly and jointly, was assessed on Nile tilapia (Oreochromis niloticus) fingerlings. Median let...

Zinc (Zn) and vitamin E (VE) are essential micro-nutrients that contribute a pivotal role in the physiology and nutrition of fish. An experiment was designed to know the effects of Zn and VE addition in the diet on growth and feed utilization in Nile tilapia (Oreochromis niloticus). Four diets containing Zn (80 mg/kg), VE (50 mg/kg), Zn (80 mg/kg) + VE (50 mg/kg), and without Zn and VE (control) were fed to Nile tilapia in aquaria with triplicate groups for 6 weeks. Survival, growth parameters (weight gain, WG; %WG; specific growth rate, SGR), and feed utilization (protein efficiency ratio, PER; feed conversion ratio, FCR) were calculated at the end of the feeding trial. Several hemato-biochemical parameters (hemoglobin, Hb; red blood cell, RBC; white blood cell, WBC, and glucose) and morphology of muscle were analyzed. The growth parameters (WG, %WG, and SGR) and feed utilization (FCR and PER) improved significantly in the fish fed with Zn, VE, and Zn + VE supplemented diets. There was no significant change in the values of Hb, RBC, WBC, and glucose level among different groups. Significantly improved diameter of muscle fiber, reduced distance between muscle fiber, and increased number of the nucleus and hyperplastic muscle fiber were observed in the fish fed with Zn, VE, and Zn + VE supplemented diets. These results suggested that Zn and VE can be effectively incorporated into the diets of Nile tilapia for better growth with maximum feed utilization.

A 21-days feeding screening period was conducted to highlight the protective efficacy of dietary chitosan nanoparticles (CSNPs) on pendimethalin (PD)-induced toxicity in Nile tilapia (Oreochromis niloticus). Hematology, non-specific immune response, the antioxidative enzymes [superoxide dismutase (SOD) and catalase (CAT), glutathione reduced (GSH), and glutathione peroxidase (GPx)] in the liver and anterior kidney, changes of pro-inflammatory cytokine genes [interleukins-8 (IL-8), interleukins-1β (IL-1β), and tumor necrosis-α (TNF-α)] in the anterior kidney and histopathological alterations were assessed. Fish (50 ± 7.5 g) were randomly assigned into four groups (Three replicates), the first group served as the negative control and fed on the control diet only, and the second group served as the positive control and fed on the control diet supplemented with CSNPs (1 g kg−1 diet). The two other groups were exposed to 1/10 96-h LC50 PD (0.5 mg L−1) in rearing water and simultaneously fed the control diet alone or supplemented with CSNPs (1 g kg−1 diet), respectively. Fish were fed on the experimental diets twice a day for 21 days. The results revealed that PD exposure caused a significant decline in the survival rate of the Nile tilapia, as well as in most of the hematological indices, respiratory burst activity, phagocytic activity, total immunoglobulin levels, lysozyme, and bactericidal activity. Additionally, PD toxicity markedly suppressed most of the antioxidative enzymatic activities in both tissues together with upregulation of immune genes (IL-8 and TNF-α); however, IL-1β expression remained unaffected. The histopathological results revealed marked pathological changes in spleen, liver and intestine with a notable decrease of intestinal goblet cells in PD-exposed groups. Conversely, CSNPs exerted protective effects through improving the above mentioned parameters. Thus, CSNPs supplementation exhibited defensive effects against PD toxicity in Nile tilapia that might provide an insight into the promising role of CSNPs as a potential immunomodulatory feed additive for tilapia in aquaculture.

Recirculating Aquaculture Systems (RAS) offers a better option to increase aquaculture production with limited land and water resources while minimizing water pollution. The biggest challenges in RAS is to maintain favorable water quality for the fish to thrive. The practice of RAS in Kenya is minimal with the improper matching of RAS components and production densities for the existing few and in most cases, leading to a system failure. This study aimed at evaluating environmental and energy requirements for different production biomass of Nile tilapia in a RAS established in a controlled environment. Both production densities and water flow rates were varied while at the same time, the water quality parameters (dissolved oxygen, ammonia, pH, electrical conductivity and temperature) were monitored. The energy consumed for pumping and aeration was also monitored. Tilapia stocking biomass varied from 2.3 kg/m3 to 10 kg/m3 while flow rate was varied from 2.0 L/min and increased at intervals of 1.0 L/min to the maximum attainable flow rate of 10.0 L/min. Crushed pumice rock packed in a 1000 L tank and equipped with a bell siphon was used as the biofilter. Ammonia removal reduced with increasing flow rate with removal rates of 75% at 2.0–3.0 L/min to 9% at 8.0–10.0 L/min. The water pH increased with increasing flow rate with R2 ranging from 0.4 to 0.9. Electrical conductivity increased with flow rate from 112 mg/L to as high as 209 mg/L. Dissolved oxygen increased with flow rate and ranged from 1.0 mg/L to 7.0 mg/L. Energy consumption increased with flow rate and raged from 0.4 kW h at 2.3 kg/m3 stocking biomass to 2.4 kW h at 10 kg/m3 stocking biomass. High stocking densities and flow rates resulted to lower purification efficiencies and higher power consumptions than low stocking densities and flow rates. In order to maintain good RAS water quality, increased production and profits among farmers using RAS in Kenya, there is need to give proper advice on the right combination of stocking biomass, power, and water flow rate. In addition, similar studies should be carried out for other common fish species such as the African catfish.

A 60-day experiment was performed to assess the efficacy of dietary Astragalus membranaceus polysaccharides (ASP) in attenuation of sub-lethal thallium (Tl) toxicity in Nile tilapia. Six experimental groups (in triplicates) were designed where a fish group was raised in clean water and fed basal diet and served as control (CONT), two groups were fed the basal diet supplemented with 0.15% and 0.30% ASP (ASPL and ASPH), Tl-intoxicated group exposed to 1/10 of 96-h LC50 (= 41.9 μg/L), and two other groups were fed 0.15% and 0.30% ASP and concomitantly exposed to 41.9 μg Tl/L (ASPL-Tl and ASPH-Tl). At the end of the experiment, fish behavioral responses, clinical signs, survivability, growth, whole-body composition, intestinal digestive enzymes, serum biochemical parameters, hepatic antioxidative biomarkers, and transcription of stress and apoptosis genes were assessed. Results showed that the whole-body composition, intestinal α-amylase and protease enzymes, serum AST and blood urea levels, and hepatic GSH were not significantly different among groups (P 0.05). The Tl-intoxicated fish group was off food, had darkened skin, showed restlessness and hyperexcitability, and high mortalities. FBW, WG, SGR and FI were significantly decreased alongside increase FCR in the Tl-exposed group. Tl exposure caused significant increases (P 0.05) in intestinal lipase enzyme and serum indices such as ALT, creatinine, total cholesterol, triglycerides, glucose, and cortisol levels. Moreover, a significant decreases in hepatic CAT and SOD enzyme activities and significant increases in hepatic MDA contents were also noticed (P 0.05). Furthermore, Tl exposure induced significant upregulation of hepatic HSP70 and apoptosis-related genes (p53 and caspase 3). Interestingly, dietary supplementation with ASP in ASPL-Tl and ASPH-Tl groups modulated the parameters mentioned above but still not reached the CONT values. Altogether, this study suggests that ASP could be beneficial in the modulation of sub-lethal Tl toxicity effects in Nile tilapia. Additionally, we can conclude that using natural feed supplements such as ASP in aquafeed might be necessary for maintaining the overall health performances of Nile tilapia.

MicroRNAs (miRNAs) are short noncoding sequences that can regulate the expression of target genes. Erythrocytes, also called red blood cells (RBCs), are the largest proportion of cells in blood. Erythrocytes deliver oxygen in the body of vertebrates and contribute to the body's immune function. Illumina sequencing technology was used to analyze pooled RNA samples isolated from erythrocytes, in order to characterize their gene expression profile and increase the range of miRNAs identified in Nile tilapia erythrocytes. This study identified conserved (n = 309) and novel (n = 194) miRNAs. Quantitative reverse-transcription polymerase chain reaction and next-generation sequencing results indicated that miR-451 was the most abundant in RBCs, followed by let-7a-1, miR-2188 and miR-144. Moreover, the tissue expression mode of these highly expressed miRNAs was characterized. Results show that miR-451, miR-2188, and miR-144 were all highly expressed in RBCs but were low abundance in other tissues. miR-1 and miR-10b were also abundantly expressed in muscle, while miR-122 was abundantly expressed in the liver. let-7a-1, miR-10b, and miR-1 were significantly higher in the testis than in the ovary. The tissue distribution of miRNAs implies that these noncoding sequences have a potential role in regulating tissue differentiation or maintaining tissue characteristics. The results of a dual-luciferase reporter assay indicated that miR-144 and miR-10b inhibited the expression of the meningioma expressed antigen 5 gene in vitro. This study contributes to the Nile tilapia miRNA database and reveals the profile of erythrocyte miRNA expression.

This study aimed to assess Salmonella spp. prevalence in aquaculture Nile tilapia commercialized in the Federal District, Brazil, and determine the antimicrobial resistance profile of the isolates....

Made available in DSpace on 2022-04-28T19:44:03Z (GMT). No. of bitstreams: 0 Previous issue date: 2021-11-01 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Group B Streptococcus (GBS) causes meningitis in neonates and Nile tilapia (Oreochromis niloticus). The molecular mechanisms regulating the intracellular survival of this pathogen in the host cell are complex and crucial for the progression of infection. Thus, we propose the use of GBS-infected Nile tilapia microglia as an in vitro model system simulating infection caused by homologous bacteria in humans. We used this model to evaluate the phagocytic activity, as well as the functional aspects of the capsular proteins A, B, C, and D and the major redox enzymes, and the synergistic role of mechanisms/proteins involved in blocking phagocytic process. We observed that in the intracellular phase, GBS showed enhanced synthesis of the polysaccharide capsule and used superoxide dismutase, thioredoxin, NADH oxidase, and alkyl hydroperoxide reductase to scavenge reactive oxygen species and reactive nitrogen species produced by the host cell. Furthermore, although these virulence mechanisms were effective during the initial hours of infection, they were not able to subvert microglial responses, which partially neutralized the infection. Altogether, our findings provided important information regarding the intracellular survival mechanisms of GBS and perspectives for the production of new drugs and vaccines, through the druggability analysis of specific proteins. In conclusion, tilapia microglia serve as a potent in vitro experimental model for the study of meningitis. Department of Postgraduate in Health Sciences-PROCISA Federal University of Roraima (UFRR) Immunochemistry Laboratory Butantan Institute (CeTICs/FAPESP), Vital Brazil Avenue, 1500 Department of Technology School of Agrarian and Veterinary Sciences Sao Paulo State University (Unesp) Immunoregulation Unit of the Laboratory of Applied Toxinology (CeTICs/FAPESP) Butantan Institute, Vital Brazil Avenue, 1500 Department of Technology School of Agrarian and Veterinary Sciences Sao Paulo State University (Unesp)

This work aimed to assess the effect of the probiotic strain, Lactobacillus plantarum, on the levels of leptin, IGF-1 and their receptors on the hepatopancreatic tissues of Nile tilapia (Oreochromis niloticus) and then correlate fish growth performance and gut microbiological parameters. Fish juveniles (±23g) were reared in a recirculation system with constant aeration and temperature (25°C). They were distributed into six polyethylene tanks (45L) and fed twice a day at 5% of the tank biomass with the respective diets: control (commercial diet without probiotic) and supplemented with L. plantarum inoculum (1 x 108 CFU mL-1), both in triplicate. After 30 days of feeding, L. plantarum-fed fishes showed greater weekly growth rate, final weight, and feed conversion rate, in addition to higher count of lactic-acid bacteria and lower count of pathogenic bacteria in the intestinal tract, when compared to the control group. The immunostaining intensity for IGF-1 and leptin hormones was lower after L. plantarum supplementation than in the control group, with no change in the level for receptors. This reduction could implicate important changes in fish metabolism and homeostasis. RESUMO O presente trabalho teve como objetivo avaliar o efeito da cepa probiótica Lactobacillus plantarum sobre os níveis de leptina, IGF-1 e seus receptores no tecido hepatopancreático de tilápia-do-nilo (Oreochromis niloticus) e correlacionar com o desempenho zootécnico e os parâmetros microbiológicos intestinais dos peixes. Juvenis de tilápia-do-nilo (±23g) foram distribuídos em seis tanques de polietileno (45L) conectados a um sistema de recirculação, com aeração e temperatura constantes (25°C). Os peixes foram alimentados duas vezes ao dia, a 5% da biomassa do tanque, com as respectivas dietas: controle (dieta comercial sem probiótico) e suplementada com L. plantarum (1 x 108 UFC mL-1), ambas em triplicata. Após 30 dias de cultivo, os peixes alimentados com L. plantarum apresentaram maiores ganho de peso semanal, peso final e conversão alimentar, bem como maior contagem de bactérias ácido-láticas e menor contagem de bactérias patogênicas no trato intestinal das tilápias alimentadas com dieta probiótica, em comparação ao grupo controle. A intensidade da imunomarcação para os hormônios IGF-1 e leptina foi menor com a suplementação de L. plantarum do que no grupo controle, sem alterar os níveis de seus receptores. Essa redução pode implicar mudanças importantes no metabolismo e na homeostase dos peixes.

The risk of the waterborne toxicity caused by herbicides threatens the aquatic environment. In this study, propolis nanoparticles were shown to relieve the impacts of glyphosate-induced oxidative stress and immunosuppression in Nile tilapia. The control group was fed a basal diet and maintained in a glyphosate-free water (control). Simultaneously, the other three groups were exposed to sublethal concentrations of glyphosate (0.6 mg/L) and fed diets containing 0 and 10 g propolis and 10 g propolis nanoparticles for 4 weeks. Nile tilapia exposed to glyphosate for 2 and 4 weeks exhibited a significant increase in serum alanine aminotransferase, aspartate aminotransferase, urea, and creatinine values compared to the control. After 2 and 4 weeks, fish exposed to glyphosate who were not fed propolis and propolis nanoparticles showed a significant reduction in total protein, albumin, and globulin levels, lysozyme activity, and total immunoglobulin levels. Nile tilapia exposed to glyphosate displayed a significant increase in blood glucose and cortisol concentrations after 2 and 4 weeks. Furthermore, liver and gill tissues from fish exposed to glyphosate exhibited a significant increase in malondialdehyde (MDA) concentrations. Conversely, a statistically significant decrease was observed in the liver and gill MDA levels and AChE activity of the groups treated with propolis and propolis nanoparticles compared to the groups exposed to glyphosate and fed the basal diet. Fish exposed to glyphosate for 2 and 4 weeks showed a significant decrease (p

Fishmeal (FM) is the main protein source in fish feed. However, it is quite expensive due to its limited resources. Therefore, finding a dietary alternative to the FM to sustain fish production is crucial, and the current study was performed to assess the impact of poultry offal silage (POS) with or without betaine supplementation; as an effective and cheaper alternative to FM; on feed efficiency, growth performance, spleen morphology and intestinal morphometry of Nile tilapia (Oreochromis niloticus) fingerlings. Four dietary treatments were formulated: (1) FM based diet, (2) FM-B; FM diet +0.7% betaine, (3) POS diet and (4) POS-B; POS diet +0.7% betaine. Each dietary treatment consisted of three replicates (n = 10/replicate), and the experiment was continued for 16 weeks. By the end of the experiment, spleen and intestine specimens were collected from 15 fish (n = 5/replicate) for histopathological assessment. The results were statistically analysed using GLM procedures of SAS 9.4. Feed efficiency increased in both POS-B and FM-B groups (p = 0.01), while body weight and body weight gain showed only weak tendencies towards an increase (p = 0.10 and 0.12, respectively). The villi length was the highest in POS-B fed group (p

Aims: To determine the profitability of using a commercial tilapia feed to produce three different size ranges (1.0-1.9, 2.0-2.9 and 5.0-5.9 g) of Nile tilapia, Oreochromis niloticus fingerlings in hapa-in-pond system. Study Design: Completely randomized design. Place and Duration of Study: The Aquaculture Research and Development Centre (ARDEC), Akosombo, of Water Research Institute (WRI) of Council for Scientific and Industrial Research (CSIR), Ghana, from March to May, 2020. Methodology: Fish growth study was carried out in three (3) fine mesh netting hapas, each of dimensions 5.0 x 2.0 x 1.2 m. Nile tilapia fry at initial mean weight 0.03 ± 0.01 g were stocked at a density of 50 fish m-2 and they were fed at 20 % body weight five times daily. The feeding of the fish continued until those in all the 3 hapas attained a mean weight of at least 5.0 g. Then the experiment was terminated and all the survived fish in each hapa were harvested, counted, and their individual body weights were measured. Growth performance indicators and profitability of producing the various size categories (1.0-1.9, 2.0-2.9 and 5.0-5.9) were determined. Results: The fry attained the target size ranges of 1.0-1.9, 2.0-2.9 and 5.0-5.9 g in 4, 6 and 9 weeks respectively. There were significant differences (ANOVA, P = 0.03) among final mean weights, weight gains, feed intakes, daily weight gains, feed efficiencies and harvested biomass among all size ranges, with those of 5.0-5.9 g being significantly higher (Tukey’s HSDT, P < 0.02). Sizes of fingerlings produced correlate positively with cost of feed used. The profit indices ranged from 2.57 to 10.22, with the highest recorded in the 1.0-1.9 g fingerlings and the least in those of 5.0-5.9 g. Conclusion: The results indicated that, at the current Nile tilapia fingerlings cost and the time taken to produce the various size categories, the 1.0-1.9 g production is the most profitable.

L-carnitine (LC) and α-Ketoglutarate (AKG) are important growth promoters used in aquafeed. The study aimed to evaluate the incorporation of LC and AKG at different ratios in the diet of tilapia (initial weight 1.38 ± 0.03 g) in order to facilitate lipid utilization and protein synthesis. Fish were fed six isonitrogenous (~ 30 g/100 g CP) and isolipidic (~ 6 g/100 g CL) diets containing graded LC/AKG ratios of 0 (Control), 0.11, 0.42, 1.00, 2.33 and 9.00 in six treatments for 60 days. Fish fed with LC/AKG ratios 2.33 and 9.00 showed significantly (P

Two on-farm juvenile performance trials were conducted at a hatchery in Bangladesh to compare a genetically improved strain of farmed Nile tilapia (GIFT) and a local strain (LS) produced by commercial operators. A 21-day early nursing trial was conducted in five replicate hapas followed by a 27-day advanced nursing trial in six replicate hapas. The mean feed conversion ratios (FCR), mean specific growth rates (SGR), mean individual final weights, mean production yields and mean survival rates were calculated for both strains. During the early nursing trial, GIFT fry survival rate and overall yield were significantly (p < 0.05) greater than LS values, which in contrast demonstrated better FCR and SGR. Improved performance was demonstrated in terms of FCR, SGR and yield for GIFT during the advanced nursing trial and mean final individual weights were 78% greater for GIFT than LS fish (2.26 g and 1.27 g respectively). Economic analysis indicated GIFT fish produced a net return 84% greater than that of LS fish at the end of the early nursing period, and by the end of the advanced nursing period, this difference had grown further such that GIFT generated a gross return over double that of LS. The results from a survey of tilapia grow-out farmers suggested producers from poor, medium and better-off backgrounds agreed GIFT performed better than traditional strains and is beneficial for aquaculture growth in Bangladesh. However, the results also indicate there may be a greater propensity for better-off farmers to appreciate the potential benefits of improved strains over poorer farmers.

Two diets were formulated, a low lysine (LowL) and a balanced lysine diet (BalL), containing 9.10 and 13.10 g lysine kg−1 feed, respectively. Twenty fish (30.2 ± 1.9 g) per tank were stocked in 110-L tanks, mounted in a recycling aquaculture system (RAS), and nine hundred fish (17.2 ± 1.6 g) per pond were stocked in 200 m2 fertilized ponds (FPS). Four replicates in RAS and five replicates in FPS were assigned for each diet tested. Fish were fed with the experimental diets at a feeding rate based on metabolic body weight, twice daily for 70 days. Fish fed the BalL diet in RAS had a higher yield (kg m−3), specific growth rate, nitrogen retention efficiency (%), protein efficiency ratio (g g−1 protein), protein content and essential amino acid content, as well as a better feed conversion ratio (p .05) affect the growth indices of nutrient utilization, survival (%), body composition and essential amino acids or nitrogen utilization efficiency. Percentage compositions of plankton in the gut contents and plankton abundances in water were approximately the same between diets. The Pearson correlation coefficient (r) between plankton abundance and growth in fish fed the LowL diet was.761 and −.961 for phytoplankton and zooplankton, respectively, compared with.50 and.54 in fish fed the BalL diet. The contribution of the natural food to nitrogen gain was 30% in fish fed the LowL diet, compared with 21% in fish fed the BalL diet (p

The purpose of this study was to evaluate the effect of Bacillus spp. mixture (Bacillus subtilis TISTR001, Bacillus megaterium TISTR067, and Bacillus licheniformis DF001) (1 × 106 CFU/g) on growth, immune parameters, immune-related gene expression, and resistance of Nile tilapia against Streptococcus agalactiae AAHM04. Fish were fed different concentrations of Bacillus spp. 0 (control; T1), 1 (T2), 3 (T3), and 5 (T4) g/kg diets for 120 days. The results showed that weight gain, average daily gain, specific growth rate, feed conversion ratio in T3 diet were significantly higher than the control group and other tested diets (p 0.05) were noticed in all treatments. No significant differences in survival rate after the challenge test with S. agalactiae AAHM04 were found in fish fed Bacillus spp. mixture diets, except for the T3 diet. These results suggest that Bacillus spp. mixture diet at 3 g/kg diet (T3) could improve growth, immune response, and disease resistance of Nile tilapia.