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Objective: We sought to assess the efficacy of feeding tocotrienol, a member of the vitamin E family, as it impacts physiological functions in fingerling fish. Methods: Fingerling Largemouth Bass Micropterus nigricans with an initial mean body weight (±SD) of 0.98 ± 0.09 g were fed five diets containing tocotrienol at 0, 10, 20, 30, and 40 mg/kg (T0, T10, T20, T30, and T40 diets, respectively) for 42 days. After the feeding experiment, fish were challenged with Largemouth Bass ranavirus (LMBV) and monitored for 48 h. Result: Findings indicated a positive impact of tocotrienol‐supplemented diets on fingerling survival. Furthermore, the weight gain and specific growth rate of fish that received the T30 and T40 diets were significantly higher than those of fish that were fed the T0 diet. Tocotrienol supplementation improved the protein efficiency ratio and condition factor and increased the whole‐body lipid and protein content. Conversely, the hepatosomatic index, viscerosomatic index, and feed conversion ratio were significantly decreased by tocotrienol supplementation. Fish that were fed the T30 and T40 diets exhibited significantly higher hepatopancreas lipase activity and intestinal protease activity. Generally, superoxide dismutase and catalase activities in the liver increased as the tocotrienol level increased. Additionally, the liver malondialdehyde concentration decreased, and there was an improvement in the structure of liver cell tissue. Survival at 48 h after the LMBV challenge was significantly higher in fish that were fed the T30 and T40 diets compared to fish that were given the T0 diet. Maximum specific growth rate was observed at a tocotrienol concentration of 33.63 mg/kg. Conclusion: Results suggest that supplementation of Largemouth Bass fingerling diets with appropriate quantities of tocotrienol can enhance survival, growth, antioxidant capacity, digestion, and uptake of nutrients as well as disease resistance. Impact statementThe survival and growth performance of Largemouth Bass fingerlings were improved by adding tocotrienol at a concentration of 33.63 mg/kg in the diet. [ABSTRACT FROM AUTHOR]

The present research work was done to elucidate tomato vegetable plant growth cultivated in a floating raft aquaponics system with rohu and tilapia fishes. The experiment was conducted for 60 days in two treatments i.e., plant+rohu fish (T1) and plant+tilapia fish (T2). The replications (10) containing 400 L water stocked with fish fingerlings in the ratio of 1:1 (plants and fish) were reared to follow the standard cultivation methods, e.g., aeration, supplementary feeding, water exchange, etc. and growth measurements were taken every 15 days. The findings show that initial and final growth of 13.763 cm and 25.643 cm of plants were noted in T1, whereas 13.581 cm and 22.467 cm were recorded in T2. The net gain in plant growth was 11.880 cm in T1 and 8.886 cm in T2. Similarly, these findings indicated the increasing order 2.314<2.621<3.010<3.935 and 1.462<1.966<2.547<2.911 of plant growth at fortnightly intervals in T1 and T2, respectively. On the basis of these findings, it can be concluded that the growth of the tomato plant was more in T1 compared to T2 and plant growth in T1 and T2 variation was significant (p<0.05) may be due to more nitrogenous compounds released by the fish waste. [ABSTRACT FROM AUTHOR]

Rapidly increasing hatchery-raised Nile tilapia (Oreochromis niloticus) in most developing countries lack informed recommended fingerling weight for stocking in semi-intensive grow-out ponds. The current study assessed the growth performance, survival and productivity of all-male Nile tilapia fingerlings of 0.2 g, 1 g, and 5 g in an on-farm experiment. The final mean weight of fingerlings stocked at size 5 g was significantly higher (113.80±4.21 g) (P<0.05) compared to the 0.2 g (36.99±1.14 g) and 1g (91.93±5.59 g) fingerling sizes. The mean daily weight gain was highest in 5 g stocked fingerlings (0.91±0.04 g day -1) resulting in significant differences in the final mean weight. The coefficient of correlation between fish body length and weight was high and positive ranging (R=0.95-0.98). Significantly low percent survival was recorded in 0.2 g stocked fingerlings (64.4 3±1.93%). The net annual fish yield (NAY) and profit index (PI) were significantly lower at the 0.2 g. The highest NAY and PI were recorded in the 5 g stocked fingerlings (8.59±0.09 tons ha-1 year-1 and 6.6±2.08), respectively. Thus, with appropriate Nile tilapia fingerling weight at stocking, fish farmers can maximize fish growth, yield and profits. [ABSTRACT FROM AUTHOR]

The objective of this study was to evaluate the effects of taurine, an amino acid additive, on grass carp Ctenopharyngodon idella fingerlings (3.16 ± 0.14 gm) growth and feed utilization in glass aquaria for 70 days. Before beginning the feeding experiment, 120 fish were acclimatized for 10days in the laboratories of fisheries department and marine resources, Agriculture College, University of Basrah. Fish fed dietary taurine at levels of 1% (T2), 2% (T3), and 3% (T4) were compared to fish fed a control diet with no taurine (0%, T1). The weight gain (WG) in the T1 was 16.95 g, which was significantly (P≤0.05) higher than the other treatments. T1 had a higher (P≤0.05) mean relative growth rate (RGR) (54.89± 5.66 %) than the other treatments. The specific growth rate (SGR) and daily growth rate (DGR) of T1 were 0.72 ± 0.06 % day-1, and 0.28 ±0.01 g, which was also higher (P<0.05) than other treatments supported with different levels of taurine. Significant differences (P≤0.05) were found in the food conversion ratio (FCR) and food conversion efficiency (FCE) between T1 and the other treatments (T2, T3, and T4). It is clear from the current study that the T1 (0% taurine) better than the other treatments in growth and food utilization indicators. It is concluded from the current study that the addition of taurine (1, 2 and 3%) had inhibited the growth in grass carp fingerlings. [ABSTRACT FROM AUTHOR]

The present study was carried out in FRP pools (1.5 × 1.0 × 0.75 m) for the period of 120 days to evaluate the possibility of dietary incorporation of kinnow peel powder (KPP) as feed additive in supplementary feed of common carp (Cyprinus carpio L.) fingerlings. Healthy fingerlings of common carp were equally distributed (@15 nos. /pool) in five feeding treatments having three replicates each. Five iso-proteinous experimental feeds, containing KPP at 0 (KPP0), 0.5 (KPP1), 1.0 (KPP2), 1.50 (KPP3) and 2.0% (KPP4) inclusion levels were fed to fingerlings at 2% of fish body weight. The overall result revealed that all the water quality parameters stayed well within the optimum range throughout the experimental period in all the treatments, which showed that addition of KPP in fish feed has no adverse effect on water quality. Fish survival % ranged between 88.89 to 93.33% in KPP fed treatments (KPP1-KPP4) as compared to 88.89% in control (KPP0). Growth performance, with respect to net weight gain (NWG) and specific growth rate (SGR) of fish was significantly improved (P≤0.05) in all the KPP fed treatments, being highest (22.0 g and 0.93%, respectively) at 1.5% inclusion level (KPP3) and lowest in control (15.97g and 0.78%, respectively). Inclusion of KPP in fish feed also improved the feed utilization efficiency (FCR and PER) and among all the treatments, best (P≤0.05) feed utilization efficiency (FCR 1.94 and PER 1.96) was recorded in 1.5% KPP fed treatment as compared to control (FCR 2.37 and PER 1.58). Inclusion of KPP in fish feed also improved the flesh quality of fish. The total protein content (wet weight basis) in fish flesh was significant (P≤0.05) higher in all the KPP fed treatments and depicted maximum enhancement (16.25%) at 1.5% inclusion level (KPP3) as compared to control. The overall results revealed that dietary inclusion of KPP @ 1.5% in the fish feed can enhance growth performance, feed utilization efficiency and flesh quality of common carp. [ABSTRACT FROM AUTHOR]

The present study was designed to evaluate the effect of soluble polysaccharides in Spirulina platensis microalgae on growth performance, body composition and immune response of rainbow trout (Oncorhynchus mykiss). In this regard, 180 rainbow trout (17.22 ± 0.5g) were selected and distributed in five experimental treatments (with three replications). Treatments included different levels of polysaccharide in dosage of 0 (control), 500, 1000, 2000 and 3000 mg / kg of feed distributed in 15 fiber glass tanks (100 liters). Fish fingerlings were fed three times a day by satiation for 8 weeks. According to the results, in growth indices (final weight, body weight gain, specific growth factor, protein efficiency, feed conversion ratio and condition factor), no significant difference was observed among the treatments, However, the slight improvement was observed at 500 mg polysaccharide / kg diet. The survival was high in all treatments without any significant difference. Regarding the chemical composition of the body, the highest and the lowest amount of carcass proteins were observed in the diet containing 500 mg polysaccharide and control, which showed a significant difference. No significant difference was observed in the amount of ash, moisture and fat in treatments (P <0.05). The amount of fatty acids of the muscle of the fish body did not show any significant difference among the treatments. The amount of SFA in the control treatment was higher than other treatments. MUFA in 500 mg treatment, PUFA in the treatment of 2000 mg and HUFA and n3 / n6 levels in the treatment of 3000 mg polysaccharides per kg of diet were highest. The level of lysozyme and alternative complement activity of serum was significantly different in different treatments (P <0.05), so that the highest and lowest levels of lysozyme activity were observed in treatments of 2,000 mg polysaccharide and control and the highest and lowest levels of complement activity were observed in treatments containing 3000 mg polysaccharide and control respectively (P <0.05). In general, the use of polysaccharide extracted from micro-algae did not significantly improve rainbow trout growth, but a slight improvement in growth and body composition (protein) in 500 mg polysaccharide per kg of diet was observed. In terms of safety indicators, treatments of 2,000 and 3,000 mg of polysaccharides per kg of diet had a good performance and could be used whenever needed. [ABSTRACT FROM AUTHOR]

Stocking density of fish is species specific and is considered as one of the crucial aspects for optimizing feed and water-quality management in biofloc system. The present study was carried out to determine the optimum stocking density of a prime aquaculture species, climbing perch Anabastestudineus in biofloc system. Fish fingerlings with a mean initial weight of 0.80 ± 0.02 g were reared in biofloc tanks for 13 weeks under three different stocking densities, 300 (T-300), 450 (T-450), and 600 (T-600) fish m−3 in triplicates, and the fish were fed with a commercial diet at 3% of their body weight. At final harvest, significant differences in growth and body composition were observed among the treatments. T-300 and T-450 showed similar growth pattern (p > 0.05), while fish in T-600 registered significantly poor growth (p < 0.05). The fitted models for all the growth variables were quadratic, and daily individual feed intake was linear. Although the regression model for yield was not significant (p = 0.072), the highest yield (kg m−3) was attained in T-450. Dry matter, protein, and lipid content of fish remained unaffected (p > 0.05), while significant (p < 0.05) difference in ash content was observed among the treatments with the highest being found in fish from T-600. These results suggest that at the initial stage of culture the optimum stocking density of climbing perch in biofloc system is 300–450 fish m−3 although higher stocking might be feasible considering periodic water exchange and solid management, a proposition awaits further elucidation. [ABSTRACT FROM AUTHOR]

Background: Stunting is a process of suppressing growth from unfavourable conditions. The protein supplementation during stunting gives scope to maintain the nutrient reserves of fish and its quality. Methods: A feeding trial was conducted for eight months to study the effect of three hetero-nitrogenous diets with 25% (control), 30% (T1) and 35% (T2) crude protein (CP) levels on growth and physio-metabolic responses of Chanos chanos fingerlings during stunting. Milk fish fingerlings with a mean body weight of 11.71±0.18 g were stocked in earthen ponds @ 20 no/m2 in each replicate (n=3) was fed @ 2% biomass throughout the experiment. Result: Fish fed with T1 diet showed better specific growth rate (0.64±0.01% d-1), weight gain percentage (362.56±14.95) and protease activity (7.53±0.25 U/mg protein). Whereas, lower activity was observed for the enzyme assay, namely superoxide dismutase (45.41±2.50 U/min/mg protein), aspartate aminotransferase (34.01±1.88 U/min/mg protein) and alanine aminotransferase (39.64±0.64 U/min/mg protein). Hence, it may be concluded that the dietary protein inclusion level of 30% CP showed better growth performance and lower physio-metabolic response in milkfish fingerlings during the stunting. [ABSTRACT FROM AUTHOR]

The present study was designed to investigate the effects of dietary non-encapsulated and microencapsulated Lactobacillus delbrueckii subsp. bulgaricus on growth performance, intestinal enzymatic activities, antioxidant capacity and hepato-biochemical parameters of rainbow trout before or after exposure to lead via diet. Fingerling fish (16 ± 4 g) were divided into four groups: negative control (NC), positive control (PC), probiotic (PR) and encapsulated probiotic (EN-PR). During the pre-exposure period (days 0–45), fish in the NC and PC groups received the basal diet, whereas fish in the PR and EN-PR groups were fed with basal diet containing 108 CFU g−1 feed of non-encapsulated and microencapsulated probiotic, respectively. During the exposure period (days 46–66), the fish in the probiotic and PC groups were co-treated with 500 μg g−1 feed of lead nitrate. Blood, liver and gut samples were taken at days 0, 45, 52, 59 and 66. The results revealed that growth performance and intestinal enzymatic activities were significantly (P<0.05) improved in the probiotic groups compared to the NC group (day 45). Dietary exposure to lead resulted in the highest levels of liver aspartate aminotransferase (AST), liver alkaline phosphatase (ALP) and serum malondialdehyde (MDA), and the lowest activities of serum superoxide dismutase (SOD) and catalase (CAT) in the PC group (day 66). The levels of liver ALP were significantly (P<0.05) lower in the probiotic groups compared to the NC and PC groups prior to and after exposure to dietary lead. Serum levels of total protein, albumin, SOD, CAT and glutathione (GSH) were significantly increased in fish fed with both non-encapsulated and microencapsulated probiotics (P<0.05). However, microencapsulated probiotic showed the greatest potential for alleviation of the disturbed activities of intestinal and hepatic enzymes, and improvement of serum biochemical and antioxidant parameters. Our findings suggest that L. delbrueckii subsp. bulgaricus, particularly in the microencapsulated form, can be used as a potential probiotic to protect rainbow trout from dietborne lead toxicity. [ABSTRACT FROM AUTHOR]

Abstract: A 16‐week feeding trial was conducted to determine the dietary pantothenic acid requirement of fingerling Channa punctatus. Six casein–gelatin‐based diets (450 g/kg CP; 18.39 kJ/g GE) with graded levels of pantothenic acid (0, 10, 20, 30, 40 and 50 mg/kg diet) were fed to triplicate groups of fish (6.2 ± 0.71 cm; 4.26 ± 0.37 g) near to apparent satiation. The growth evaluation in terms of absolute weight gain (AWG), feed conversion ratio (FCR) and protein retention efficiency (PRE) indicated the best performance (p < .05) in fish fed diet containing 30 mg/kg pantothenic acid. Highest haemoglobin, haematocrit and RBCs counts were also obtained in fish fed diet with 30 mg/kg pantothenic acid. Mean cell haemoglobin and mean cell volume were found to be lowest in fish fed pantothenic acid‐free diet indicating the anaemia in this group of fish. Superoxidase dismutase and catalase activities of liver tissue were found to improve (p < .05) with the increasing levels of dietary pantothenic acid from 0 to 30 mg/kg. However, liver pantothenic acid concentration responded positively with the increasing levels of pantothenic acid up to 40 mg/kg diet and then stagnation in liver pantothenic acid concentration with the further inclusion of pantothenic acid was recorded. Second‐degree polynomial regression analysis of AWG, FCR and PRE exhibited the pantothenic acid requirement at 36.4, 32.8 and 34.7 mg/kg diet, respectively. Data generated during this study would be useful in formulating pantothenic acid‐balanced commercial feeds for the intensive culture of this fish. [ABSTRACT FROM AUTHOR]

Abstract: This study examined four experimental diets with different protein concentrations and sources for pond‐raised fingerling hybrid catfish, ♀ Ictalurus punctatus × ♂ Ictalurus furcatus. A 35% protein diet with fishmeal was used as the control diet. Test diets were 32 and 28% all‐plant‐protein diets and a 28% protein diet with porcine meat, bone, and blood meal. Small fingerlings with a mean initial weight of 2.9 g/fish were stocked into 20 earthen ponds (0.04 ha) at a density of 172,970 fish/ha. They were fed once daily to apparent satiation for 107 d. No significant differences were observed for total diet fed, gross yield, final weight, survival, or condition factor among dietary treatments. However, fish fed the 28 and 32% all‐plant‐protein diets had a significantly higher feed conversion ratio than fish fed the 35% protein diet with fishmeal. There were no significant differences in chlorophyll a and nitrite concentrations in the pond water, but ponds receiving the 35% protein diet had significantly higher ammonia than those receiving 28% protein diets. Economic analysis suggested potential cost savings by using low‐protein and all‐plant‐protein diets for hybrid catfish fingerling production. [ABSTRACT FROM AUTHOR]

Summary: A 16‐week experiment was accomplished to determine the dietary niacin requirement of fingerling Channa punctatus (6.8 ± 0.92 cm; 4.65 ± 0.46 g) by feeding seven casein‐gelatin based isonitrogenous (450 g/kg CP) and isoenergetic (18.39 kJ/g GE) diets with graded levels of niacin (0, 10, 20, 30, 40, 50 and 60 mg/kg diet) twice a day to apparent satiation to triplicate groups of fish. Significantly best absolute weight gain (AWG; 38.19 g/fish), feed conversion ratio (FCR; 1.42) and protein retention efficiency (PRE; 26.47%) were registered in fish fed 40 mg niacin/kg diet. Also, fish fed above diet exhibited maximum carcass protein. Hemoglobin (Hb), RBCs counts and hematocrit (Hct) were improved with the incremental levels of dietary niacin up to 40 mg/kg. However, liver niacin content showed the positive correlation up to 50 mg/kg niacin and then leveled off. Fingerling C. punctatus fed niacin‐free diet showed retarded growth, poor feed utilization, high mortality, difficult motion and skin haemorrhage. Broken‐line regression analysis of AWG, FCR and PRE indicated that fingerling C. punctatus require niacin in the range of 37.1–42.1, whereas that of liver niacin concentration indicated the niacin requirement at 52.3 mg/kg dry diet. [ABSTRACT FROM AUTHOR]

Seven casein gelatin-based diets containing 450 g/kg CP and 18.39 kJ/g GE with different levels of pyridoxine (0, 2, 4, 6, 8, 10, and 12 mg/kg diet) were fed to fingerling Channa punctatus (4.66 ± 0.46 g) for 12 weeks to determine pyridoxine requirement. Highest absolute weight gain (AWG; 25.81 g/fish, P < 0.05), protein retention (PRE; 23.69%, P < 0.05), energy retention efficiencies (ERE; 69.63%, P < 0.05), and minimum feed conversion ratio (FCR; 1.48) were noted at 8 mg pyridoxine/kg diet. However, liver pyridoxine content achieved the positive correlation as the dietary pyridoxine increased up to 10mg/kg. On the basis of broken-line analysis of AWG, PRE, FCR, and liver pyridoxine data, pyridoxine requirement is recommended between 7.6 and 10.4 mg/kg of dry diet. [ABSTRACT FROM AUTHOR]

Carbon nanotube are mainly utilized for water purification, but they may be toxic to aquatic organisms including fishes, crustaceans etc. Hence, the present study was conducted to investigate the effects of multiwalled carbon nanotube (MWCNT) on growth, survival and feed intake of fingerlings of a fresh water fish. Results showed that initially no mortality observed at 100 mg × L-1 of nanotube concentration up to 7 days. Later on mortality was observed in all test groups. There were reductions in specific growth rate, mass and length of fish in response to treatment of nanotube. These declines were concentration dependent. Survival of fingerlings decreased with increasing concentration of MWCNT. This suggests that there should be limited use of carbon nanotube in order to avoid its toxicological effects on piscine system. [ABSTRACT FROM AUTHOR]

Abstract: Dietary thiamin requirement of fingerling Channa punctatus was quantified by feeding casein/gelatin‐based diets (450 g/kg CP; 18.39 kJ/g GE) with seven graded levels of thiamin (0, 0.5, 1, 1.5, 2, 2.5 and 5 mg/kg diet) to triplicate groups of fish (6.9 ± 0.93 cm; 4.91 ± 0.62 g) for 16 weeks. Fish fed diet with 2.5 mg/kg thiamin reflected highest absolute weight gain (AWG), protein gain (PG), RNA/DNA ratio and lowest feed conversion ratio. Similarly, highest liver thiamin concentration was also recorded in fish fed 2.5 mg/kg thiamin diet. Hepatic thiobarbituric acid reactive substance (TBARS) concentration responded negatively with increasing concentrations of dietary thiamin up to 2.5 mg/kg, whereas superoxide dismutase and catalase activities were found to improve with the increasing levels of dietary thiamin from 0 to 2.5 mg/kg. Transketolase activity also improved as the thiamin concentrations increased up to 2.5 mg/kg. Broken‐line regression analysis of AWG, PG, RNA/DNA ratio, liver thiamin concentrations, transketolase and TBARS activities exhibited the thiamin requirement in the range of 2.34–2.59 mg/kg diet. Data generated during this study would be useful in formulating thiamin‐balanced feeds for the intensive culture of this fish. [ABSTRACT FROM AUTHOR]

Abstract: An 84‐day feeding experiment was conducted to determine the effects of dietary ginseng extract (GE), tribulus extract (TE) and date palm pollen grains (DPPG) on growth, testosterone level and nutrient utilization of Nile tilapia, Oreochromis niloticus, fingerlings. Seven experimental treatments were conducted in three replicates: control fed basal diets without any supplementations, GE0.2 (supplemented with 0.2 g GE/kg diet), GE0.4 (supplemented with 0.4 g GE/kg diet), TE0.6 (supplemented with 0.6 g TE/kg diet), TE1.2 (supplemented with 1.2 g TE/kg diet), DPPG3 (supplemented with 3 g DPPG/kg diet) and DPPG6 (supplemented with 6 g DPPG/kg diet). The results indicated that all dietary phytochemicals significantly increased growth compared to the control. Plasma testosterone levels were improved by 86.27%, 64.58%, 57.35% and 24.58% with TE1.2, GE0.4, TE0.6 and DPPG6, respectively, more than the control. The relationship between testosterone and final body weight showed a significant simple linear regression with a positive correlation. The nutrient utilization imprxoved with higher doses of phytochemical supplementations. Moreover, protein content increased and ether extract decreased with phytochemical supplementation. The present results concluded that higher doses of GE, TE and DPPG could be used as growth promoters and testosterone boosters for Nile tilapia fingerlings. [ABSTRACT FROM AUTHOR]

Abstract: A 16‐week experiment was conducted to determine the dietary riboflavin requirement of the fingerling Channa punctatus (6.7 ± 0.85 cm; 4.75 ± 0.72 g) by a feeding casein–gelatin‐based (450 g/kg crude protein; 18.39 kJ/g gross energy) purified diet containing graded levels of riboflavin (0, 2, 4, 6, 8, 10 and 12 mg/kg diet) to triplicate groups of fish near to satiation at 09:30 and 16:30 hr. Absolute weight gain (AWG), protein efficiency ratio (PER), specific growth rate (SGR, % per day), protein retention efficiency (PRE%) and RNA/DNA ratio were positively affected by increasing concentrations of dietary riboflavin to 6 mg riboflavin per kg diet. Feed conversion ratio (FCR) decreased up to 6 mg riboflavin per kg diet but did not decrease further with higher riboflavin supplementation. Hepatic thiobarbituric acid‐reactive substance (TBARS) concentration also supported the pattern of FCR, whereas superoxide dismutase and catalase activities increased with increasing concentrations of dietary riboflavin from 0 to 6 mg/kg. Liver riboflavin concentrations increased with increasing levels of riboflavin up to 8 mg/kg diet. Broken‐line regression analysis of AWG, PRE and liver riboflavin concentrations of fingerling C. punctatus with dietary riboflavin level indicated optimum growth and liver riboflavin saturation at 5.7, 6.1 and 7.7 mg riboflavin per kg diet, respectively. [ABSTRACT FROM AUTHOR]

The experiment was conducted to determine the effect of different protein feeds on the growth performance and survival rate of silver moony, Monodactylus argenteus. Four formulated diets with graded protein levels, T1 (22%), T2 (28%), T3 (35%) and T4 (40%) were fed to fish for a period of 90 days. The significantly (P<0.01) highest mean weight gain, feed conversion rate, specific growth rate and survival were observed in T4, followed by T3, T2 and lowest values were recorded in T1. The increase in dietary protein levels were resulted in an increase in growth and survival of fish. In considering these results, it can be concluded the diet containing 40% protein diet is optimal for growth and survival of silver moony. [ABSTRACT FROM AUTHOR]

A 45 days experiment was conducted to assess the growth, survival and cannibalism at different feeding rate in striped snakehead, Channa striata (Bloch, 1793) fingerlings. In this experiment, four hundred fifty striped murrel fingerlings of average weight 1.41±0.12g were randomly distributed in 15 tanks of 250 L water capacity. Fishes were fed pelleted diet having 44.1% protein with different feeding rate 2% (T1), 4% (T2), 6% (T3), 8% (T4) and 10% (T5) of fish biomass. The weight gain, percentage weigh gain and specific growth rate was significantly higher (p<0.05) in T3 and T4 in comparison to T1and T2 groups. The cannibalism rate was significantly higher (p<0.05) in T1 (2%) group in comparison to T3, T4 and T5. Cannibalism rate was gradually reduced with increase in feeding rate and significantly higher cannibalism (12.22±1.94) was observed at 2% of feeding rate (T1) in comparison to the other treatment groups. The hepatosomatic index (HSI) and viscerosomatic index (VSI) was significantly higher in T5 group in comparison to other treatment groups. This study indicated that feeding rate at 6% of biomass of striped snakehead fingerlings is optimum for better growth and survival and to minimize the cannibalism. [ABSTRACT FROM AUTHOR]

To investigate the effect of scheduled meal timings on growth performance in Cirrhinus mrigala fingerlings, two experiments were conducted. The first experiment was conducted under laboratory conditions and the fish were submitted to schedule meal timings (at 08:00, 12:00,16:00, 20:00, 00:00 and 04:00). A control on continuous feeding was also maintained. ANOVA had revealed a significant ( p < .05) increase in live weight gain (g), growth per cent gain in body weight, specific growth rate, PER, GPR, GER and APD (%) values in fingerlings fed between 12:00 and 16:00 hours. A decline in growth parameters, nutrient retention and an increase in FCR values were observed in the group fed at 20:00, 00:00 hours and also in the control group. Studies have further revealed that meal timings had also significantly ( p < .005) affected protein digestibility, nitrogen retention and excretion of metabolites . Fish carcass composition had significantly ( p < .05) higher accumulation of protein (14.82 ± 0.032), fat (5.51 ± 0.006) and energy (5.95 ± 0.004) in the group fed at 16:00 hours. The second experiment was conducted under field conditions and the fish were submitted to schedule meal timings (at 08:00, 12:00, 16:00 and 20:00). A control on continuous feeding was also maintained. Significantly ( p < .05) higher values in growth parameters were observed in the group fed at 16:00 hours and lower values in the group fed at 20:00 hours and also in controls. Water quality, nutrients and productivity status of ponds revealed favourable levels and appears to have been affected by meal timings. Thus, in C. mrigala, timings of food intake can serve to optimize the utilization of ingested calories. [ABSTRACT FROM AUTHOR]

An 8-week feeding trial was conducted to assess the effects of dietary l-threonine on growth, protein utilization, threonine retention efficiencies, nucleic acid indices and body composition of fingerling Heteropneustes fossilis (6.6 ± 0.1 g; 10.9 ± 0.2 cm). Casein-gelatin based isonitrogenous (38% crude protein; CP) and isocaloric (15.3 kJ g−1 digestible energy; DE) amino acid test diets with six levels of dietary l-threonine (0.75%; 1.0%; 1.25%; 1.5%; 1.75%; 2.0% dry diet) were prepared and hand-fed to quadruplicate groups of fingerling to apparent visual satiation twice daily. Weight gain (WG; 46.3 g fish−1), feed conversion ratio (FCR; 1.98), protein utilization efficiency (PUE; 0.25), threonine retention efficiency (TRE; 0.69), lipid productive value (LPV; 0.45), body protein (18.2%) and RNA/DNA ratio (3.6) of fish fed graded levels of dietary threonine increased significantly ( P < 0.05) up to 1.49% threonine of dry diet. To generate precise information, the WG, RNA/DNA and LPV data were subjected to broken-line and quadratic regression analyses. The two models were superimposed and requirement was determined by establishing the point, where the quadratic curve first intersected the plateau of broken-line. Based on the above mathematical analyses, optimum dietary threonine requirement of fingerling H. fossilis was estimated to range between 1.62% and 1.69% of the diet, corresponding to 4.26-4.44% protein. [ABSTRACT FROM AUTHOR]

The present study was conducted to investigate the effects of fenugreek seed meal ( FKSM) on growth performance, blood haematological and biochemical factors, survival and stress resistance of the common carp (2.46 ± 0.06 g) fingerlings. Four practical diets containing 0 (control), 0.5%, 1% and 1.5% FKSM were used to feed fish. Fish were fed on the tested diets at a rate of 3% of body weight for 8 weeks. Results indicated that fish fed the control diet had a significantly lower weight gain, specific growth rate and condition factor compared to the other treatments ( P < 0.05). Feed conversion ratio decreased significantly in fish fed diets containing FKSM. There were no significant differences in glucose levels, red blood cell count, haematocrit and haemoglobin between treatment groups and the control group ( P > 0.05). Significantly lower white blood cells count was observed in fish treatment with FKSM when compared with the control group ( P < 0.05). The cholesterol level in group fed supplemented diet by 1% fenugreek significantly lower than other groups ( P < 0.05). Total protein levels were significantly higher in all treatments compared to the control ( P < 0.05). No mortality was recorded during the feeding trial. In salinity stress experiment, highest survival rate belong to fish fed supplemented diet by 1% fenugreek. These results indicate that FKSM can be considered as a beneficial dietary supplement for improving the growth performance and blood indices of common carp fingerling. [ABSTRACT FROM AUTHOR]

Detoxified Jatropha protein isolate ( DJPI), prepared from Jatropha seed cake was hydrolysed using Alcalase 2.4L FG. Both DJPI and hydrolysed DJPI ( HDJPI) were evaluated as a fish meal ( FM) replacement in common carp ( Cyprinus carpio L.) diets. The peptide concentration in HDJPI was determined using matrix-assisted laser desorption ionization-time of flight mass spectrometer ( MALDI- TOF). Twenty-two peptides with molecular mass ranging from m/z 906.455 to 1774.943 Da were identified. Fingerlings (45; av. wt. 10.1 ± 0.4 g) were randomly distributed in five groups with three replicates. An 8-week feeding experiment was conducted to compare the nutritional quality of the HDJPI, DJPI and FM. Fish were fed on iso-nitrogenous diets: control ( FM based protein), J50 (50% of FM protein replaced by DJPI), J75 (75% of FM protein replaced by DJPI), JH50 (50% of FM protein replaced by HDJPI) and JH75 (75% of FM protein replaced by HDJPI). Growth performance was higher for FM fed group compared with the other groups, while nutrient utilization parameters were similar for control and J50 groups and superior ( P < 0.05) to J75 and both the HDJPI fed groups. No variation ( P > 0.05) was observed in blood albumin and hepatosomatic index among all different groups. Blood urea nitrogen, calcium, sodium and potassium ions in the blood were similar among all five groups. [ABSTRACT FROM AUTHOR]

This study aimed to investigate the optimal dietary vitamin B 12 requirement of fingerling blunt snout bream Megalobrama amblycephala based on the results of growth performance, intestinal digestive and absorptive capability and responses of the growth hormone (GH)-insulin-like growth factor-I (IGF-I) axis. Fish (initial body weight: 0.71 ± 0.03 g) were randomly assigned to six purified diets containing graded levels of vitamin B 12 (0, 0.028, 0.051, 0.12, 0.23 and 0.41 mg/kg) for 12 weeks. Both weight gain (WG) and specific growth rate increased significantly ( P < 0.05) as dietary vitamin B 12 levels increased from 0 to 0.051 mg/kg, then plateaued with further increasing levels. Feed conversion ratio decreased as dietary vitamin B 12 levels increased from 0 to 0.12 mg/kg, but no statistical difference was observed. Whole-body composition and intestinal brush border enzymes activities also exerted little difference within the vitamin B 12 range tested, whereas hepatic vitamin B 12 contents increased remarkably ( P < 0.01) with increasing dietary vitamin B 12 levels. Intestinal protease, amylase and lipase activities all increased significantly ( P < 0.05) as dietary vitamin B 12 levels increased from 0 to 0.12 mg/kg, but decreased remarkably ( P < 0.05) with further increasing vitamin B 12 levels. Similar results were also observed in hepatic IGF-I expressions. Furthermore, the mRNA expressions of GH in the brain decreased significantly ( P < 0.05) with increasing dietary vitamin B 12 levels. Based on the broken-line regression analysis of WG, the optimal dietary vitamin B 12 requirement of fingerling blunt snout bream was estimated to be 0.06 mg/kg. In addition, a supplementation of 0.12 mg/kg vitamin B 12 boosted intestinal digestive capability and hepatic IGF-I expression. Statement of relevance This study investigated the optimal dietary vitamin B 12 requirement of fingerling blunt snout bream based on growth performance. The underlying mechanisms were also investigated with emphasis on intestinal digestive and absorptive capability and modulation of the GH-IGF-I axis. Data obtained here might facilitate the development of low-cost formulated feed for aquatic species. [ABSTRACT FROM AUTHOR]

Growth, survival and production of endangered Indian butter catfish ( Ompok bimaculatus) fingerlings were examined at different stocking densities. The experiment was conducted for 8 months in nine earthen ponds having an area of 0.03 ha each. 30-day-old fingerling, stocked at 40 000 ha−1 was designated as treatment-1 (T1), 50 000 ha−1 as treatment-2 (T2) and 60 000 ha−1 as treatment-3 (T3). At stocking, all fingerlings were of same age group with a mean length and weight of 3.36 ± 0.08 cm and weight of 0.83 ± 0.02 g respectively. Fish in all the treatments were fed with a mixture of rice bran (50%), mustard oil cake (30%), fish meal (19%) and vitamin-mineral premix (1%). Physicochemical parameters, plankton populations and soil parameters were at the optimum level for fish culture. Highest weight gain was observed in T1 and lowest in T3. Final length, weight and survival of fish also followed the same trend as weight gain. Highest specific growth rate was observed in T1 followed by T2 and T3. Feed conversion ratio was significantly lower in T1 followed by T2 and T3 in that order. Significantly higher amount of fish was produced in T1 than T2 and T3 respectively. Higher net benefit was obtained from T1 than from T2 and T3. Overall, the highest growth, survival and benefit of fish were obtained at a density of 40 000 fingerlings ha−1. Hence, of the three stocking densities, 40 000 fingerlings ha−1 appears to be the most suitable stocking density for culturing of Indian butter catfish in grow-out system. [ABSTRACT FROM AUTHOR]

To investigate the histidine requirement of fingerling Catla catla (3.65 ± 0.15 cm; 0.65 ± 0.36 g), six casein-gelatin based diets (33% CP; 13.58 kJ g−1 DE) containing graded levels of L-histidine (0.25%, 0.39%, 0.53%, 0.67%, 0.83%, 0.96% of the dry diet) were fed near to satiation thrice a day for 12 weeks. Maximum absolute weight gain (AWG; 8.63 g fish−1), protein gain (PG; 1.45 g fish−1), histidine gain (HG, 48.19 mg fish−1), RNA/DNA ratio (4.15), best feed conversion ratio (FCR; 1.31), highest haemoglobin (Hb, 9.61 g dL−1), RBCs (2.84 × 106 mm−3) and haematocrit (Ht, 30.12%) were recorded in fish fed diet containing 0.67% histidine. However, broken-line regression analysis of AWG, PG, HG, RNA/DNA ratio, FCR, Hb, Ht and RBCs against dietary histidine reflected the histidine requirement at 0.65%, 0.64%, 0.63%, 0.68%, 0.63%, 0.66%, 0.68% and 0.65% dry diet respectively. Carcass protein was found to improve significantly ( P < 0.05) from 13.36% to 16.42% with the increase in dietary histidine from 0.25% to 0.67%. Based on regression analysis of AWG, PG, HG, RNA/DNA ratio, FCR, Hb, Ht and RBCs, it is recommended that the diet for fingerling catla should contain histidine in the range of 0.63-0.68% dry diet, equivalent to 1.91-2.06% of the dietary protein for optimum growth, feed utilization, blood profile and carcass composition. [ABSTRACT FROM AUTHOR]

Silver nanoparticle, which is known for its anti-bacterial and anti-fungal properties, also exhibits very hazardous and toxic effects on the environment and living beings. It creates highly toxic environment for fishes showing negative effects on fish growth and survival. Various studies have been done on silver nanoparticles but information is very limited about their impacts on growth of fishes. In the present study, we tried to analyse the effects of silver nanoparticles on growth, feed intake and survival of fingerlings of a freshwater fish. Exposure of fish to silver nanoparticles increased mortality, decreased specific growth rate (SGR) and reduced feed intake in the fingerlings. It also declined the body mass as compared to the control group. Increasing the silver nanoparticle toxicity attenuated the fish development and body activities. Therefore, it is suggested that the use of silver nanoparticles should be minimized to save aquatic fauna. [ABSTRACT FROM AUTHOR]

Two separate 12 weeks feeding trials were performed to quantify the total sulphur amino acid (TSAA) requirement (experiment I) and cysteine replacement value for methionine (experiment II) of fingerling Catla catla. In experiment I, six casein-gelatin based (33% crude protein; 16.72 kJ g-1 gross energy) diets with graded levels of TSAA (0.56%, 0.81%, 1.06%, 1.31%, 1.56%, 1.81% dry diet) were fed to triplicate groups of fish (3.55 ± 0.06 cm; 0.65 ± 0.02 g) near to satiation. The TSAA requirement was determined by quadratic regression analysis of absolute weight gain (AWG), protein efficiency ratio (PER), feed efficiency (FE), protein gain (PG) and TSAA gain (TSAAG) against dietary TSAA concentrations at 95% maximum response. Above analysis revealed that inclusion of TSAA at 1.28% dry diet (1.22% methionine + 0.06% cysteine), corresponding to 3.87% of dietary protein is optimum. In experiment II, to determine the replacement value of cysteine for methionine, six diets containing 1.28% TSAA determined in experiment I with different ratios of L-methionine and L-cysteine (80:20, 70:30, 60:40, 50:50, 40:60, 30:70) on equimolar sulphur basis were fed to fish (3.65 ± 0.08 cm; 0.67 ± 0.04 g). Broken-line regression analysis of AWG, PER, FE, PG and TSAAG against varying methionine to cysteine ratios yielded the optimum cysteine replacement value at 40.3%. Based on above analysis, it is recommended that inclusion of 1.28% dietary TSAA, corresponding to 3.87% of dietary protein is optimum of which 40.3% could be spared by cysteine. Data generated during this study would be useful in formulating TSAA balanced, cost-effective feeds for the intensive culture of this fish. [ABSTRACT FROM AUTHOR]

A 12-week feeding trial was conducted in eighteen 70 L indoor polyvinyl circular troughs provided with a water flow-through system (1-1.5 L min−1) at 28 ± 1 °C to evaluate the dietary tryptophan requirement of fingerling Catla catla (3.45 ± 0.24 cm; 0.60 ± 0.13 g). Six casein-gelatin-based amino acid test diets (330 g kg−1 crude protein; 13.6 kJ g−1 digestible energy) containing graded levels of L-tryptophan (1.0, 1.4, 1.9, 2.3, 2.8, 3.4 g kg−1 dry diet) were fed to triplicate groups of fish near to satiation at 08:00, 12:30 and 17:30 h. Absolute weight gain, feed conversion ratio, protein gain, RNA/DNA ratio, hepatosomatic index, viscerosomatic index, condition factor and haematological indices improved with the increasing levels of tryptophan from 1.0 to 2.3 g kg−1 of dry diet. Significantly higher carcass protein was obtained at 2.3 g tryptophan per kilogram of the dry diet. Exponential analysis of absolute weight gain, feed conversion ratio, protein gain and RNA/DNA ratio against dietary tryptophan levels at 95% maximum and minimum responses displayed the tryptophan requirement at 2.5, 2.3, 2.5 and 2.1 g kg−1 dry diet, respectively. Inclusion of dietary tryptophan in the range of 2.1-2.5 g kg−1 dry diet, equivalent to 6.4-7.6 g kg−1 dietary protein, is recommended in formulating tryptophan-balanced feed for the culture of this fish species. [ABSTRACT FROM AUTHOR]

This study aimed at quantifying leucine requirement of fingerling Catla catla [3.75 (mean body length) ± 0.15 (SE) cm, 0.66 (mean body weight) ± 0.04 (SE) g] by conducting a 12-week feeding trial. Six casein- and gelatin-based (33 % crude protein, 14.0 kJ g calculated digestible energy) semipurified diets containing different concentrations of leucine (0.73, 0.97, 1.24, 1.46, 1.74 and 1.97 % dry diet) were fed to triplicate groups of fish to apparent satiation thrice daily at 08:00, 12:30 and 17:30 hours. Maximum absolute weight gain (AWG, 7.45 g fish), protein gain (PG, 1.31 g fish), leucine gain (LG, 85.33 mg fish), RNA/DNA ratio (4.62) and best feed conversion ratio (FCR, 1.51) were recorded at 1.74 % dietary leucine. Hemoglobin, hematocrit and red blood cell counts count were also found to be optimum in fish fed diet with 1.74 % leucine. Quadratic regression analysis at 95 % maximum response of AWG and minimum response of FCR against dietary leucine concentrations reflected the requirement at 1.58 and 1.57 % dry diet, respectively. Based on above results, inclusion of leucine ranging from 1.57 to 1.58 % of the dry diet is recommended for developing leucine-balanced commercial feeds for the intensive culture of C. catla. [ABSTRACT FROM AUTHOR]

Two groups of Danube salmon (Hucho hucho) fingerlings obtained from artificial propagation conducted in April/2011 on the fish farm "Perućac" in Perućac were compared. The first group was fed with a combination of Artemia salina/commercial trout feed, and the other group was fed with a combination of Gammarus sp./fish meat. Length and weight growth were monitored during the research period from 22. 06. - 14. 09. 2011. The group fed with Gammarus sp./fish meat had statistically higher weight and length gains. Specific growth rate (SGR) of the Gammarus sp./fish meat fed group was 39.06% higher than that of the group fed by brine shrimp and trout feed. The weight of fingerlings had most effect on complete transfer to commercial trout food diet, without addition of Artemia salina nauplii, and was average 0,846 g. Condition factor in the group fed with the Gammarus sp./fish meat combination was 15.55% higher than one in the group fed with the Artemia salina/commercial trout feed combination. Less positive correlation between weight and total length and greater coefficient of variation shows that growth was more unstable in the group fed with the Artemia salina/commercial trout feed combination. [ABSTRACT FROM AUTHOR]

A feeding trial was performed to determine the effect of substituting fish oil with a 1:1 mixture of soybean and linseed oil on growth, phosphorus and nitrogen excretion, and lipid deposition of rainbow trout fingerlings. Diets with soy protein concentrate and soybean meal were prepared with 25, 50, and 75% substitution of fish oil with plant oils. Soy protein concentrate and soybean meal were used with fish oil at 100% in the control diet. Triplicate groups of 15 juveniles with an initial weight of 0.74 ± 0.05 g (mean ± standard error) were fed the experimental diets for 70 days. Growth performance, protein, and lipid digestibility, oxygen consumption, nitrogen, and phosphorus excretion, and lipid deposition (liver and muscle) were determined. The mixture of plant oils did not affect the growth performance of fingerlings. Apparent digestibility of lipids decreased as the fish oil in the diet decreased. A significant decrease of phosphorus excretion was observed as plant oils in the diets were increased. Lipid deposition was higher in liver unrelated to plant oil concentration in the diet. The results show that it is possible to use high quantities of plant ingredients in the diets without affecting the growth performance and lipid deposition, as well as significantly decreasing phosphorus excretion. [ABSTRACT FROM AUTHOR]

In this study we evaluated the effect of three levels of Biogut (a probiotic) on growth performance of common carp fingerlings. Biogut was incorporated into a formulated diet (protein level: 35%) at 0.5, 1.0 and 1.5% of the diet and designated as T1, T2 and T3 and T0, the fourth (control) diet, without biogut. The diets were fed to common carp fingerlings, stocked at 10/tank, with three replicates, for 60 days. Results indicated that the common carp fingerlings fed with the diets containing biogut exhibited increased growth compared to those fed the control diet. The survival rate was 100% in all the groups. The average weight and length of common carp was maximal in the 0.5% biogut treated group. Specific growth rate, protein efficiency ratio, RNA/DNA ratio and protease activity were also highest in the group fed on 0.5% biogut. The results demonstrate that 0.5% biogut supplementation in the diet of common carp fingerlings produces positive effects. [ABSTRACT FROM AUTHOR]

Chlorpyrifos ethyl is a popular insecticide widely used in agriculture within the Vietnamese Mekong delta, including for rice farming. Here, local farmers often apply pesticides at very high rates which leads to contamination of the surrounding environment. Silver barb (Barbonymus gonionotus) is a fish species indigenous to the delta, which resides in a variety of water bodies and is also commonly cultivated in rice–fish systems. As a result, this species is at high risk of exposure to chlorpyrifos ethyl. This study aims to determine the lethal concentration (LC50) of chlorpyrifos ethyl, as well as the effects of sub-lethal concentrations on the activity of cholinesterase and growth of Silver barb. Lethal concentration testing was conducted in a static non-renewed system. Three concentrations of chlorpyrifos ethyl (1%, 10% and 20% LC50-96 h) were conducted in triplicate to assess the effects of chlorpyrifos ethyl on the brain cholinesterase (ChE) of fingerling fish for 15 days, and on their growth for 60 days. Results showed that chlorpyrifos ethyl was highly toxic to fingerling Silver barb with a LC50-96 h of 0.119 ppm. The lowest observed effect concentration (LOEC) was 1%LC50-96 h for ChE and 10%LC50-96 h for growth. No observed effect concentration (NOEC) of chlorpyrifos ethyl for growth was 1%LC50-96 h. The result from this study suggests that ChE activity is significantly inhibited at environmentally realistic concentrations in the Vietnamese Mekong delta and can be used as a biomarker of pesticide exposure. Further study in the rice fields as well as in the canals or rivers is required. [ABSTRACT FROM AUTHOR]

The experiment was conducted to assess the growth performance and feed utilization of Clarias gariepinus under the feeding frequencies of T1 (twice/day), T2 (thrice/day), and T3 (four times/day) at 3% BWD per day over a period of 56 days. A total of 180 fingerlings with average weight of 2.39±0.19g and average length of 5.02±1.04cm were stocked at 15 fish per plastic container of 35 litres capacity. The highest weight gain recorded at the end of the experiment was 7.39±0.19g in (T3) and the lowest was 5.35±0.31g in (T1). The highest specific growth rate (SGR%) value of 1.19±0.02 was recorded in (T3) and the lowest 1.01±0.03 was recorded in (T1). T3 recorded the highest FCR value of 1.88±1.37, while the lowest value of 8.34±2.12 was obtained in (T1). Therefore, Treatment 3 yielded the best performance in terms of WG, SGR, and FCR and can be recommended for enhanced growth performance and optimum feed utilization. [ABSTRACT FROM AUTHOR]