Monosex Nile Tilapia Research Articles

Impact of Biofloc technology on growth performance and biochemical parameters of Oreochromis niloticus.

In the present study, the experiments were conducted during the period from June to October 2019 (20-weeks) to evaluate the effect of Biofloc technology (BFT) on mono sex Nile tilapia, Oreochromis niloticus fingerlings. It was focused on water quality, growth parameters, hepatosomatic index (HIS), spleenosomatic index (SSI), Hematology, and biochemistry. Triplicated treatments were designed, two Biofloc treatments with two fish densities (12 &16 fish/200 L tank) vas two control groups. All treatments were fed with 3% of body weight in two equally divided meals. Rice brane and Molasse (1:1) were added as a carbon source to Biofloc treatments twice daily after one hour of main meals. Results indicated that total ammonia-N and Nitrite-N were significantly decreased at Biofloc treatments. Biofloc treatments showed significantly high average final body weight, better feed conversion ratio (FCR), and one-ninth water consumption. Biofloc addition had generally no significant difference of hematology, biochemistry, and hepatosomatic index (HSI), while spleenosomatic index (SSI) was significantly increased at high density only. It could be concluded that Biofloc treatments improve water parameters stability and fish growth performance while it decreased water consumption. High density (16 fish/200 L) is a more yield productive treatment.

Evaluation of use effective microorganisms (EM) with different feeding strategies on growth performance, body chemical composition and economic efficiency of monosex Nile tilapiaOreochromis niloticusjuveniles

A factorial trial was conducted to detect the effect of different feeding strategies of supplementation of effective microorganisms (EM) liquid on the growth performance, feed utilization, body chemical composition and economic efficiency of monosex Nile tilapia (Oreochromis niloticus) juveniles. Three experimental treatments were formulated a basal diet without any addition of EM (control; A), a diet supplemented with 2% EM (B), and a diet supplemented with 4% EM (C). All treatments were offered to fish through two different strategies of feeding the meal: 2/3 in the morning and 1/3 in the afternoon or 1/3 in the morning and 2/3 in the afternoon. Each treatment was replicated three times. Juveniles Nile tilapia with an average initial body weight of 3.85 ± 0.22 g (± SE) were randomly stocked at a rate of 90 juveniles per 1.5 m3tank. Fish growth performance and feed utilization significantly (P≤ 0.05) increased with increasing EM supplementation and were positively affected by different feeding strategies. Moreover, the economic evaluation showed that there were more benefits by when using the 4% EM diet and feeding 2/3 of daily meal in the morning.

Effect of adding Pediococcus acidilactici at low plant protein diets on growth performance of Nile tilapia (Oreochromis niloticus) fingerlings

In the present study effects of adding the probiotic Pediococcus acidilactici (PA), on growth performance, feed utilization and carcass composition of Nile tilapia, (Oreochromis niloticus) fingerlings were investigated. Four experimental diets were formulated, as isocaloric (4417.23 Kcal/kg diet), containing 25% crude protein (CP), and 23% crude protein (CP), each was either addition or not with Pediococcus acidilactici (PA) at 1g /kg diet (T1, T2, T3 and T4), respectively and fed to monosex Nile tilapia, (Oreochromis niloticus) fingerlings with average weight (2.60 ±0.01g/fish). Total of 240 fingerlings were random distributed in four treatments, triplicate groups each with twenty fish/ aquarium. The experiment period was lasted for 71 days. The results indicated that fish fed low level of crude protein (23%) in tilapia diet without Pediococcus acidilactici recorded the worst values of growth performance and feed utilization parameters. Also, fish fed with P. acidilactici presented higher weight gain and specific growth rate (SGR) and the best feed conversion ratio (FCR), protein efficiency ratios (PER), protein productive value (PPV % ) and energy utilization compared to the control diet. The results indicated that the use of 1× 109 cuf kg-1 dry feed probiotics improved growth parameters and feed utilization in Nile tilapia fingerlings.

Identification of chemical constituents responsible for potential androgenic efficacy of Withania somnifera and Chlorophytum borivilianum root solvent extracts for production of monosex Nile tilapia, Oreochromis niloticus

ABSTRACT Bioactivity-guided fractionation was performed between March and June 2019 to identify the phytoconstituents in extracts of Withania somnifera and Chlorophytum borivilianum that were responsible for androgenic efficacy by inducing maleness in Nile tilapia. Fish hatchlings were fed diets containing water, methanol, and ethanol extracts at 0.5, 0.75, and 0.9 gm/kg feed concentrations. For W. somnifera, the highest male percentage (89.63 ± 0.9) was obtained with methanol extract at 0.75 gm/kg feed concentration. For C. borivilianum, the highest male percentage (93.64 ± 0.9) was obtained with ethanol extract at 0.75 gm/kg feed concentration. Three fractions of methanol extract of Withania somnifera roots (W1 to W3) and six fractions of ethanol extract of Chlorophytum borivilianum roots (S1 to S6) were obtained through column chromatography followed by TLC. During dietary treatment (0.75 gm/kg feed) with those fractions, W1 and S4 showed higher male percentage than others. Gas chromatography-mass spectrometry analysis of W1 and S4 revealed the presence of various unsaturated fatty acids with antiaromatase activity that might be responsible for the androgenic effect of the extracts.

The effects of four plant extracts on growth, sex reversal, immunological and haemato‐biochemical parameters in Nile tilapia,Oreochmomis niloticus(Linnaeus, 1758)

Growth and immune status of monosex Nile tilapia produced through dietary treatment with solvent extracts of four plant materials were analysed. Nile tilapia juveniles (mean weight 0.025 ± 0.009g) were fed diet containing 17α-methyltestosterone (10 mg/kg feed, MT), Basella alba leaf ethanol extract (1.0 g/kg feed, EB), Tribulus terrestris seed ethanol extract (2.0 g/kg feed, ET), Mucuna pruriens seed methanol extract (0.2 g/kg feed, MM), Asparagus racemosus root methanol extract (0.2 g/kg feed, MA) for 30 days followed by basal diet for 90 days. The control group was fed basal diet for 120 days. MT, EB, ET and MA showed significantly (p < .05) higher male (%), final weight (g), final length (mm), weight gain (g), specific growth rate (%) compared with control and MM. EB and MA showed significantly (p < .05) better immunostimulatory (phagocytic, lysozyme activities, respiratory burst), haematological, antioxidant and hepatoprotective activity compared with other treatment groups. MT, EB, ET and MA showed significantly (p < .05) higher level of GH, IGF-1 and 11-KT compared with control and MM. The growth and health promoting, and immunostimulating efficacy of plant extracts may be attributed to the presence of steroidal saponins and polyphenols in them. EB and MA were more potent in growth promotion, immunostimulation and adaptogenic potential compared with other two plant materials. These two plant materials may be used as an environment friendly safe alternative to MT for production and culture of monosex Nile tilapia.

Supplementation of nano‐selenium in fish diet: Impact on selenium assimilation and immune-regulated selenoproteome expression in monosex Nile tilapia (Oreochromis niloticus)

Selenium (Se), a fundamental element of nutrigenomic science in fish nutrition, was used to investigate its impact on selenoproteome expression and Se regulation in tilapia. Different concentrations (T1 – 0, T2 – 0.5, T3 – 1.0 and T4 – 2.0 mg/kg of feed) of dietary nano-Se were incorporated in the diets of monosex Nile tilapia. A total of 180 tilapia fingerlings with initial weight (15.73 ± 0.05 g) were stocked in 150 L capacity FRP tanks categorized into four diet groups with triplicate each for a feeding trial of 90 days. At the end of first, second and third months of the feeding trial, gill, liver, kidney and muscle tissues were harvested to evaluate the effect on the kinetics of Se bioaccumulation and assimilation as well as immune-regulated selenoprotein transcripts (GPx2, SelJ, SelL, SelK, SelS, SelW and Sepp1a) and their synthesis factors (SPS1 and Scly). The findings depicted that significantly (p < 0.05) higher weight gain was found in the diet supplemented with 1.0 mg/kg of nano-Se. The theory of second-order polynomial regression supported the same. The liver showed significantly (p < 0.05) higher Se accumulation and concentration factor among the harvested tissues in a different timeline. All the selected immune-regulated selenoproteins and synthesis factors in different fish tissues showed significantly (p < 0.05) up-regulation in the diet supplemented with 1.0 mg/kg of nano-Se for the second month. Therefore, the present findings suggested that the supplementation of nano-Se could be more effective for improved growth, better selenium regulation and expression of immune-regulated selenoproteins in the fish model.

Using of by-products of mushroom (Pleurotus ostrateus) growing on rice straw in Nile Tilapia (Oreochromis niloticus) fingerling diets

The present study was carried out at the World Fish Abbassa Sharkia, Egypt with cooperation of Animal Production Research Institute (APRI) Agriculture Research Center Giza, Egypt. The study was conducted to investigate the possibility of incorporating by-products of mushroom growing on rice straw as an energy source and cheap alternative feed stuffs instead of the diets in all-male Nile tilapia, O. niloticus fingerlings Abbassa strain (G9) (6.03g±0.22g) were obtained from the World Fish. Genetic improvement program. Five experimental diets were formulated, as iso nitrogenous (30.80 % CP) and isocaloric (4325.94 Kcal/kg diet), containing 0, 5, 10, 15 and 20% of mushroom by-product T1, T2, T3,T4 and T5, respectively and fed to monosex Nile tilapia, (Oreochrom isniloticus) fingerlings with average individual weight of (6.03g ± 0.12g).Total of Fish were fed at a rate of 5 % of total biomass, tilapia were hand-fed to apparent satiation which was divided between three feeding times daily (8:00, 12:00, and 15:00 hours). The results showed no significant differences between all treatments (P>0.05) in growth performance and feed protein utilization of fish up to 20% compared with the control in Nile tilapia fingerlings diets resulted a better economic efficiency.

The Effect of some Dietary Medicinal Herbal Extracts on Growth Performance and Economic Efficiency of Nile Tilapia

This experiment was performed to study the effect of ginger and licorice extracts on to the diets on growth performance, feed utilization and economic efficiency besides water and fish quality. The experiment started at 15 May to 15 September 2019 for a period of 120 days at a private fish farm in Fayoum Governorate, Egypt. 1680 monosex Nile tilapia (Oreochromis niloticus) fingerlings with an average weight of 18.26 g ± 0.34 have been randomly distributed in 12 net hapa in six experimental groups (4×7×1.5 m with a water volume of 28 m3 and 140 fingerlings) suspended in an earthen pond. The diets was (T1) control group, fed on the basal diet only; T2 and T3 the basal diet sprayed with aqueous ginger extract at a rate of 2 and 4 ml/kg feed; T4 and T5 the basal diet sprayed with aqueous licorice extract at a rate of 2 and 4 ml/kg feed and T6 mix group, fed on the basal diet sprayed with 2 ml ginger plus 2 ml licorice aqueous extracts/kg feed. The results showed that ginger and licorice extract supplements were able to minimize heavy metal accumulation in the body of the fish (levels of cadmium, lead and copper) Special to expand adding. While 4 ml of licorice or ginger was better than 2 ml and combining extract better than both. Fish fed mixed diet (T6) achieved the best significant final body weight followed by dietary fish groups (T5), (T4), (T3) and (T2), respectively, Whereas control group (T1) obtained the lowest values. The best FCR and higher levels of feed intake (FI), protein efficiency ratio and PPV were obtained when fish were fed on T6 diet. Which the best significant values in all parameters. T6 showed significantly higher net yields and economic efficiency compared with other tested diets. While control diets T1 had the least economic output significantly (P≤0.05).

Growth performance, serum lipid profile, intestinal morphometry, and growth and lipid indicator gene expression analysis of mono-sex Nile tilapia fed Moringa oleifera leaf powder

The current study aimed to assess the effect of the dietary inclusion of Moringa oleifera leaf on growth performance, serum lipid profile, and intestinal morphometric analysis along with relative mRNA levels of growth and lipid metabolism related genes in mono-sex Nile tilapia. A total of 180 mono-sex Nile tilapias (Oreochromis niloticus; average body weight, 27.98 ± 0.75 g) were used. Juvenile fish were randomly allocated into three groups with three replicates in each (20 fish/tank). For 8 weeks, groups 1, 2 and 3 were fed experimental diets containing 0%, 5%, and 10 % moringa leaf powder, respectively. We observed that the dietary inclusion of moringa leaf powder at 5 % significantly improved growth performance, evidenced by an increase in final body weight and improved feed conversion ratio. Moreover, lower serum cholesterol and triglycerides levels were reported in fish fed the moringa containing diet compared with those fed the basal diet (0% moringa). The increased body weight was accompanied with changes in intestinal morphometric parameters, including increased villus length and width as well as the inter-villus space. In addition, the improved growth performance and hypolipidemic effect following moringa leaf dietary inclusion were associated with a relative increase in mRNA levels of growth hormone receptor (GHR), insulin like growth factor (IGF), lipoprotein Lipase (LPL), and fatty acid synthase (FAS). Hence, moringa leaf powder can be included in the Nile tilapia diet as an alternative feed ingredient to promote growth and induce a hypolipidemic effect.

IMPACT OF DIETARY PROTEIN AND AQUA-MAX PLUS® ON GROWTH, FEED EFFICIENCY, AND PHYSIOLOGICAL RESPONSES OF MONO-SEX NILE TILAPIA (Oreochromis niloticus, L. 1758)

This experiment was designed to estimate the effect of different levels of dietary protein with the addition of Aqua-Max Plus® (as a feed additive) on growth performance, feed utilization, the chemical composition of the whole fish body, and physiological responses of mono-sex Nile tilapia, Oreochromis niloticus. Six hundred of mono-sex Nile tilapia fingerlings (at average initial bodyweight 52.64 ± 5.2 g) were distributed randomly to five treatments. Experimental diets contain different levels of dietary crude protein 21, 23, 25, 27% (referred to No. T1, T2, T3, and T4, respectively) and that were compared to the control diet contains 25% without adding Aqua-Max Plus® (T0). Results revealed that the increasing dietary protein in diets leads to an improvement in growth performance and hematological parameters as well as total protein, albumin, and globulin concentrations in blood serum. Fish fed on a diet containing 21% protein (T1) recorded the lowest values of growth performance, feed efficiency, and hematological parameters. The addition of Aqua-Max Plus® to diets containing 23% (T2) and 25% (T3) crude protein enhanced growth performance and feed efficiency parameters compared to the control diet. Protein content was significantly improved, whereas fat, ash and EC contents were reduced by increasing the dietary protein. The addition of Aqua-Max Plus® to the experimental diets had no significant effect on serum biochemical parameters. Finally, the addition of Aqua-Max Plus® in the Nile tilapia diets improve the nutritional values of low protein diets, and it is a way to reduce the cost of fish feed.

Nutritional studies on partial replacement of soybean meal by (Jatropha curcas) meal in Nile tilapia (Oreochromis niloticus) fingerlings diets

This study was undertaken to investigate the efficiency of partial replacement of soybean meal (SBM) by Jatropha curcas meal treated with lactobacillus acidophilus at rate of 1g/100kg. Four experimental diets were formulated, as iso nitrogenous (30.5 % crude protein) and isocaloric (4543.56Kcal/kg diet), containing 0, 25, 50 and 75% of treated Jatropha meal (TJM) T1, T2, T3 and T4, respectively and fed to monosex Nile tilapia, (Oreochromis niloticus) fingerlings with average weight (30.43±1.14g/fish).Total of 60 fingerlings were random distributed in four treatments, triplicate groups each with five fish/ aquarium. The experiment period was lasted for 70 days. Growth performance, feed utilization and body compositions as well as the economic evaluation were monitored. The obtained data showed that, higher weight gain and the best feed conversion ratio (FCR), protein efficiency ratios (PER), protein productive value (PPV % ) and energy utilization (EU%) recorded for fish fed diets (up to 50 %) of treated Jatropha meal were insignificantly different from those fed soybean meal. It could be concluded that the SBM can be partial replaced with TJM up to50 % of SBM without any adverse effects on growth performance or feed utilization of Nile tilapia.

Effect of different levels of Aqua-Max Plus® on growth performance, feed efficiency and physiological responses of the mono-sex Nile tilapia (Oreochromis niloticus, L. 1758)

Effect of different levels of Aqua-Max Plus® on growth performance, feed efficiency and physiological responses of the mono-sex Nile tilapia (Oreochromis niloticus, L. 1758)

Exclusion of two microsatellite markers in the sex-linkage study of Nile tilapia (Oreochromis niloticus L.)

Monosex Nile tilapia (Oreochromis niloticus) is highly preferred in semi-intensive and intensive culture systems to prevent uncontrolled reproduction and to obtain fast growing male. Production of all male tilapia is being practiced by the hatcheries of Bangladesh mainly by administering androgen hormones (particularly 17-α-methyl-testosterone) with feed in a mixture of undifferentiated fry for about a month. The direct application of hormone to such food chain often arises question in respect to public health and safety. The alternative to this is the production of putative supermales, a rather safe but longer procedure to obtain all male progeny. However, sex determination system in tilapia is fairly complex. Recent developments have resulted in a linkage map and genetic markers that can be used to analyze the sex determination system. For genetic analysis of different genotypes of fish, microsatellite DNA marker ARO120 and ARO121 were used for studying the inheritance pattern for possible sex linkage using Polyacrylamide gel electrophoresis. In case of ARO120, it was observed that the Dam XX was heterozygous; 11 out of 22 female progeny and 10 out of 22 male progeny were found to be heterozygous. In case of ARO121, it was observed that the Dam XX was heterozygous; 16 out of 22 female progeny and 20 out of 22 male progeny were found to be heterozygous. Though the marker polymorphisms were observed in this study, these were excluded from the sexlinkage study due to limited extent of information as sex-linked markers in Nile tilapia BFRI strain. This study provides a baseline for further research using other suitable polymorphic markers for assisting marker-assisted selection.&#x0D; Res. Agric., Livest. Fish.6(1): 143-151, April 2019

Is it Possible to Feed Nile Tilapia the Diets Containing Wastes of Opuntia ficus-indica?

An indoor feeding experiment was conducted to evaluate the effects of replacing diet's corn by meals of fruit skin and leaves of Teen Barshomy (Teen Shoky) Opuntia ficus-indica on productive performance of all-males mono-sex Nile tilapia, Oreochromis nilotucus (17 g initial body weight and a total length of 9.2 cm). Ten glass aquaria (70 x 35 x 40cm) were stocked with 10 fish / aquarium. The feeding trial lasted for 75 days at a daily feeding rate 3% of the actual biomass. Five experimental diets were formulated to replace 25 and 50% of dietary corn by fig skins and fig leaves in diets (D) No. 2, 3, 4, and 5, respectively besides the control one (diet No. 1). All experimental diets were formulated and pelleted into sinking diets with an average pellets diameter and length of 2mm and 1 cm, respectively. Diets were offered to fish 6 days a week at 2 meals (8 am and 2 pm) daily. The obtained results revealed no changes in the rearing water quality criteria. Fig skin and leaves are to some extent chemically similar, but it seems that the fig skin may be more nutritious than the leaves. The replacement affected the chemical composition of the experimental diets. The dietary inclusion of fig wastes decreased the feed consumption of the experimental diets than the control, improved (P≤0.05) each of final body weight (FBW), total body gain (TBG), daily body gain (DBG), specific growth rate (SGR), relative growth rate (RGR), and feed conversion ratio (FCR) as well as whole fish body composition. Thus, it is possible to feed mono-sex Nile tilapia the diets containing fig wastes as replacers for dietary corn without adversely effects on productive performance parameters of fish.

Culture strategies, diseases and their mitigations in mono-sex Nile tilapia farming in Jessore sadar region, Bangladesh

A survey was carried out to investigate culture strategies, disease patterns and mitigations in mono-sex Nile tilapia in Jessore sadar region. Data obtained by questionnaire interview, individual interview, telephonic interview, PRA method, mono-sex Nile tilapia farm survey from four villages. It was observed that 30.769% farmers and farm owner had no training about culture of mono-sex Nile tilapia while 69.230% farmers and farm owner received short term training from different Department of Fisheries, different NGOs. Mono-sex Nile tilapia culture in ponds was basically a three-tier culture system. Pre-stocking management of ponds in the study area comprised dike repairing, aquatic weed control, waste soil removal and undesirable species (predator and trash fish) control. Majority (85%) of the farm owners and farmers depends on ground water and only (15%) depends on surface water. About 95% of farm of farm owners controlled aquatic weeds manually. Removal of predatory and undesired fish from pond used different types of chemicals but most used rotenone (80%). Fertilizer of pond preparation (Organic and inorganic) in the study area but mostly used cases inorganic fertilizers had applied at the rate of urea 114 kg/ha and triple superphosphate 60 kg/ha in 4–5 installments. Stocking density of mono-sex Nile tilapia was 200-380 fry per decimal. It was recorded that 85% of mono-sex Nile tilapia farmers and farm owner applied supplementary such as commercially manufactured feed and 12% are applied of farm made feed. It was observed,they provided heavy fertilizer, high stocking density, over feed provided, provided over dose drugs so ultimated result of disease occured. Parasitic related disease, bacterial diseases, fungal diseases, viral diseases were attacked in mono-sex Nile tilapia. Argulosis and Streptococcus were mostly common disease in this mono-sex Nile tilapia farm.&#x0D; Asian Australas. J. Biosci. Biotechnol. 2018, 3 (3), 190-200

USE OF CORN DISTILLERS DRIED GRAINS WITH SOLUBLES (DDGS) AND FOOTS IN NILE TILAPIA FINGERLINGS DIETS

The aim of this study was to investigate the use of corn distillers dried grains with solubles (DDGS) (27.11% CP) and Foots (20.84% CP) as corn processing by-products in monosex Nile tilapia, Oreochromis niloticus diets to replace yellow corn as an energy source and its effect on growth performance, nutrients utilization, whole body proximate composition, nutrients digestibility and economic efficiency. Three hundreds and seventy five fingerlings of Nile tilapia (10± 0.05 g) were randomly distributed into 15 circular plastic tanks (1000 L), representing 5 treatments. Isonitrogenous (25 to 25.84%) and isocaloric (4174.79 to 4364.65 Kcal GE/kg) experimental diets were prepared with substitution levels of DDGS 0% (T1), 20% (T2) and 40% (T3) and Foots 20% (T4) and 40% (T5). The experimental period lasted for 18 week. Results showed that both of DDGS and Foots have higher in all measured amino acids content than those in yellow corn except cysteine. Moreover, DDGS and Foots have higher content of linoleic, oleic, stearic and palmitic acids than those in yellow corn. Also DDGS and Foots covered the nutrient requirements of the essential fatty acid linoleic (18:2 ω 6) for Nile tilapia. Feed intake was significantly decreased as corn partially replaced by Foots more than the DDGS. Apparent digestibility coefficient of CP, EE, NFE and energy recorded the highest values for the T4 (75.76, 89.86%, 57.48 and 68.71%), respectively, followed by T3 with significant differences. The increasing in substitution levels of yellow corn by DDGS did not significantly (P˃0.05) had an effect on Nile tilapia performances. However weight gain and specific growth rate SGR were gradually decreased with increasing the substitution levels of Foots. The CP content of Nile tilapia carcass was significantly increased with increasing the substitution levels of DDGS (T3) and Foots (T5). Feed conversion ratio (FCR) of the fish fed diets T4 (20% Foots) was the best followed by T5 (40% Foots). The cheaper feed cost gain was obtained from T5(40% Foots) followed by T4(20% Foots).

Impact of Mono- and Polyculture Systems on Growth Performance, Feed Utilization, and Economic Efficiency of Oreochromis niloticus, Mugil cephalus, and Mugil capito

A field study was conducted to assess the effect of mono- and polyculture systems in net Hapas of monosex Nile tilapia (Oreochromis niloticus), striped mullet (Mugil cephalus) and /or thin-lipped mullet (M. capito) at different stocking ratios on growth performance, feed efficiency, chemical composition of the whole body, and economic efficiency parameters of experimental fish for 107 days rearing period. Five experimental treatments were represented as 100% Nile tilapia (T1, monoculture); 75% Nile tilapia: 25% striped mullet (T2, polyculture); 75% Nile tilapia: 13% striped mullet: 12% thin-lipped mullet (T3, polyculture); 50% Nile tilapia: 50% striped mullet (T4, polyculture) and 100% striped mullet (T5, monoculture). Fish ofT2 showed the highest significant of all growth performance, feed utilization, and economic efficiency parameters followed by the same fish species reared in polyculture system (T4) at stocking ratio (50%: 50%) compared to other experimental fish-culture systems. Generally, it could be recommended that rearing monosex O. niloticus in polyculture system with M. cephalus at stocking ratio 75%: 25%, respectively (T2) is more effective than other aquaculture systems under the experimental conditions of the present study.

EFFECT OF DIETARY PROTEIN LEVELS AND SEX ON GROWTH PERFORMANCE, FEED UTILIZATION AND BODY COMPOSITION OF NILE TILAPIA (OREOCHROMIS NILOTICUS) FRY CULTURED IN HAPS.

The effect of dietary protein levels (35%, 40% and 45%) on growth, survival, feed utilization and body composition of mono sex and mixed sex of Nile tilapia; Oreochromis niloticus L. fry was investigated. Fish were fed frequently to satiation for 7 days a week for 56 days. Results showed that fish growth was significantly affected by protein level. The highest growth performance of fry were obtained with 45% protein diet and the poorest one was obtained with 35% protein diet in both mono and mixed sex Nile tilapia, Oreochromis niloticus fry. Mono sex tilapia were reared in hap in earthen pond showed the highest weight gain, specific growth rate, feed conversion ratio, feed efficiency and protein efficiency ratio, while mixed-sex tilapia showed the lowest weight gain, specific growth rate, feed conversion ratio, feed efficiency and protein efficiency ratio. In conclusion, it was found that 45% crude protein had the highest growth performance parameters, feed utilization and economical evaluation for mono sex Nile tilapia (O. niloticus) fry under this experimental condition.

Culture strategies, diseases and their mitigations in mono-sex Nile tilapia farming in Jessore sadar region, Bangladesh

A survey was carried out to investigate culture strategies, disease patterns and mitigations in monosex Nile tilapia in Jessore sadar region. Data obtained by questionnaire interview, individual interview, telephonic interview, PRA method, mono-sex Nile tilapia farm survey from four villages. It was observed that 30.769% farmers and farm owner had no training about culture of mono-sex Nile tilapia while 69.230% farmers and farm owner received short term training from different Department of Fisheries, different NGOs. Mono-sex Nile tilapia culture in ponds was basically a three-tier culture system. Pre-stocking management of ponds in the study area comprised dike repairing, aquatic weed control, waste soil removal and undesirable species (predator and trash fish) control. Majority (85%) of the farm owners and farmers depends on ground water and only (15%) depends on surface water. About 95% of farm of farm owners controlled aquatic weeds manually. Removal of predatory and undesired fish from pond used different types of chemicals but most used rotenone (80%). Fertilizer of pond preparation (Organic and inorganic) in the study area but mostly used cases inorganic fertilizers had applied at the rate of urea 114 kg/ha and triple superphosphate 60 kg/ha in 4–5 installments. Stocking density of mono-sex Nile tilapia was 200-380 fry per decimal. It was recorded that 85% of mono-sex Nile tilapia farmers and farm owner applied supplementary such as commercially manufactured feed and 12% are applied of farm made feed. It was observed,they provided heavy fertilizer, high stocking density, over feed provided, provided over dose drugs so ultimated result of disease occured. Parasitic related disease, bacterial diseases, fungal diseases, viral diseases were attacked in mono-sex Nile tilapia. Argulosis and Streptococcus were mostly common disease in this mono-sex Nile tilapia farm.

Meningoencephalitis in farmed monosex Nile tilapia (Oreochromis niloticus L.) caused by Streptococcus agalactiae

Abstract Aquaculture of tilapia is a new research venture in India. With intensification in farming practices, tilapia are increasingly susceptible to bacterial infections. This article describes the isolation and identification of pathogenic bacteria from cultured monosex Nile tilapia, Oreochromis niloticus (L.), that experienced moderate to severe mortalities in West Bengal, India between September and August 2014 and histopathological alterations in various organs. Gram-positive diplococci, identified as Streptococcus agalactiae with Streptococcus identification kits and 16S rDNA sequencing analysis, were isolated from the brain, operculum, and kidney. Other bacteria from the kidney were identified as Aeromonas sobria, A. caviae, Klebsiella pneumoniae ssp. pneumoniae, Escherichia coli, and Enterobacter cloacae. Staphylococcus epidermis was isolated from opercular hemorrhages. Histological sections of the infected tilapia brain revealed meningoencephalitis and granulomatous lesions. Sections from other organs indicated congestion, hemorrhagic and hyperplastic cells, necrosis, vacuolation, hemosiderin deposition, hypertrophic nuclei, melanomacrophage aggregation, and ruptured veins. This report is the first description of S. agalactiae as a primary pathogen causing meningoencephalitis in cultured tilapia in India.