Central Laboratory for Aquaculture Research

Abou, Egypt

Central Laboratory for Aquaculture Research

Abou, Egypt

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Abdel-Tawwab M.,Central Laboratory for Aquaculture Research | El-Sayed G.O.,Benha University | Monier M.N.,Central Laboratory for Aquaculture Research | Shady S.H.,Central Laboratory for Aquaculture Research
Aquaculture | Year: 2017

Feed supplements are generally used to improve fish growth, health, and immunity but their potential use to enhance fish resistance against environmental stress is limited. An eight-week feeding trial was conducted to determine the effect of sodium salt of ethylene diamine tetraacetic acid (EDTA) supplementation on growth performance, biochemical and antioxidants response, body composition, and resistance of Nile tilapia, Oreochromis niloticus (L.) to environmental heavy metals (HM) exposure. Fish (16.2 ± 0.28 g) were fed on diets enriched with 0.0, 5, 10, 15, and 20 g EDTA/kg diet. After that, fish were exposed to synthetic mixture of lead (Pb), cadmium (Cd), copper (Cu), and zinc (Zn) concentrations similar to those in the natural polluted habitat for 7 days. Fish performance and feed intake improved significantly with increasing EDTA levels up to 10 g/kg diet after which fish growth declined. All biochemical variables are significantly affected by EDTA supplementation, HM exposure, and their interaction. In response to EDTA supplementation, antioxidant activities were improved due to EDTA supplementation especially when fish fed 10–20 g EDTA/kg diet. Post HM exposure, the control fish exhibited highest superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) activities and lowest malondialdehyde (MDA) value; meanwhile, antioxidant activity of fish fed 10–20 g EDTA/kg diet was significantly improved and it was near that of fish prior HM exposure. Regarding whole-fish body constituents, only crude protein content was significantly higher in EDTA-fed fish than the control fish. After HM exposure, total ash contents and HM residues were significantly higher but crude protein and total lipids contents were significantly lower than those of the control fish. It is also noticed that EDTA supplementation reduced HM concentrations in whole-fish body and subsequently reduced their impacts on biochemical and antioxidant activities especially in fish fed 10–20 g EDTA/kg diet. The polynomial regression data of this experiment recommended the use of EDTA supplement at level of 13 g/kg diet to improve fish performance and antioxidant activity. © 2017 Elsevier B.V.


Abdel-Tawwab M.,Central Laboratory for Aquaculture Research | Wafeek M.,Central Laboratory for Aquaculture Research
Journal of Thermal Biology | Year: 2014

Cadmium (Cd) is believed to be one of the most abundant and ubiquitously distributed toxins in the aquatic system. This metal is released to the aquatic environment from both anthropogenic sources, such as industrial, agricultural and urban effluents as well as natural sources, such as rocks and soils. Otherwise, the temperature increase of water bodies, which has been observed due to global climatic changes, has been shown to increase Cd toxicity for several aquatic animal species including fish. In the present study, Nile tilapia, Oreochromis niloticus (L.), (26.0±0.38. g) were reared at 20, 24, 28, or 32. °C and exposed to 0.0 or 0.5. mg Cd/L for 8 weeks to investigate effects of water temperature, Cd toxicity and their interaction on fish performance as well as metallothionein (MT) and Cd distribution in different fish organs. It was found that fish reared in Cd-free group at 28. °C showed the optimum growth and feed intake, while Cd-exposed fish showed low growth and feed intake irrespective to water temperature. A synergetic relationship between water temperature and Cd toxicity was observed where Cd toxicity increased as water temperature increased and the worse growth was obtained in Cd-exposed fish reared at 32. °C. Additionally, the highest Cd residues in different fish organs were detected in Cd-exposed fish reared at 32. °C. Similarly, MT concentrations in different fish organs increased as water temperature increased especially in Cd-exposed fish groups. A high positive correlation between MT and Cd concentrations in fish organs was detected. The distribution of MT and Cd levels was in the order of liver>kidney>gills>muscles. The present study revealed that the optimum water temperature suitable for Nile tilapia growth is 28. °C. Additionally, Cd exposure had a deteriorate effect on the growth and health of Nile tilapia. This hazardous effect increased as water temperature increased. Further, liver and kidney were the prime sites of Cd accumulation, while Cd load in the muscles was the lowest as compared to the other investigated organs. © 2014 Elsevier Ltd.


Abdel-Tawwab M.,Central Laboratory for Aquaculture Research
International Aquatic Research | Year: 2012

This study was based on a 3 × 2 factorial design with three levels of dietary protein (25%, 35%, or 45%) and two rearing densities (D1 = 150 and D2 = 300 fish/m3). In this study, Nile tilapia, Oreochromis niloticus (L.), (1. 8 to 2. 5 g) was distributed into the aquaria at a rate of 150 vs. 300 fish/m3. Fish of each density were fed on a diet containing 25%, 35%, or 45% crude protein (CP). Fish were fed on one of the experimental diets till satiation twice daily, 6 days a week, for 10 weeks. At the end of the feeding trial, blood samples were taken to determine the different physiological variables. The growth parameters were positively affected by protein level and inversely affected by stocking density, but there was no effect of their interaction. Final body weight of tilapia, fed with different levels of protein diets, varied at D1 from 7. 1 to 10. 1 g and at D2 from 6. 4 to 9. 1 g. The best feed conversion ratio was obtained with 45% and 35% CP diets at lower density with insignificant difference. The highest values of protein efficiency ratio and protein productive value were obtained with 25% CP at stock densities of 150 and 300 fish/m3. Moisture and CP contents in the whole-fish body were insignificantly affected by both factors, while ash content was significantly affected by protein level and rearing density. Total lipid content was affected by protein level alone. All physiological variables including activities of aspartate aminotransferase, alanine aminotransferase, total protein, total lipids, and glucose in plasma were significantly affected by dietary protein levels and/or rearing density. The overall results presented here indicate that the best growth performance of Nile tilapia was obtained when the fish fed on the 45% CP diet and were reared at a stocking density of 150 fish/m3. © 2012 Abdel-Tawwab; licensee Springer.


Abdel-Tawwab M.,Central Laboratory for Aquaculture Research
Journal of Applied Aquaculture | Year: 2015

This study was conducted to use ground roasted coffee bean (GRC; Coffee arabia) as a feed supplement in diets for Nile tilapia, Oreochromis niloticus. Fish (1.9 ± 0.03 g) were fed diets containing 0.0, 0.5, 1.0, 2.0, or 5.0 g GRC/kg in triplicate for 10 weeks. Final fish weight, weight gain, and specific growth rate were not significantly (P < 0.05) affected by GRC incorporation up to 1.0 g/kg, after which growth declined. Fish fed diets containing 2.0 and 5.0 g GRC/kg consumed less than the other treatments, giving the highest FCR (1.4 and 1.5, respectively). No significant differences were observed in fat efficiency ratio, protein efficiency ratio, and energy utilization for the 0.0–1.0 GRC/kg diets; lowest values of these parameters were obtained with the 2.0 and 5.0 g GRC/kg diets. Supplementation of GRC significantly reduced fish whole-body protein content and increased lipid and ash. © , Copyright © Taylor & Francis Group, LLC.


This study was carried out to evaluate the effect of American ginseng (AG), Panax quinquefolium, on growth and resistance to Aeromonas hydrophila in Nile tilapia, Oreochromis niloticus. Ginseng was included in practical test diets at rates of 0.0 (control), 0.50, 1.0, 2.0, or 5.0 g/kg diet. Fish (9.1 ± 0.3 g) were distributed into quadricated 100-L aquaria at a density of 20 fish per aquarium. Fish in all treatments were fed up to satiation twice daily for 8 weeks. After the feeding trial, fish of each treatment were intraperitoneally injected with pathogenic A. hydrophila and kept under observation for 10 days. Highest growth was obtained at 1.0 - 5.0 g AG/kg diet. The survival of fish challenged by A. hydrophila increased with increasing AG levels in fish diets. Cost-benefit analysis indicated that ginseng supplementation could reduce per kg costs by 15% with an optimum inclusion level of 2.0 g/kg. © Taylor & Francis Group, LLC.


In natural aquatic ecosystems, fish often experiences periods of poor food availability or complete starvation. The shortage in the feed for fish may ultimately interfere with pollutants toxicity. Therefore, a study based on a 3 × 2 factorial design was conducted to evaluate if feed availability may interact environmental zinc (Zn) effects on Nile tilapia, Oreochromis niloticus (L.). Fish (25.2 ± 0.88 g) were fed with 0.0, 0.5% body weight, or fed up to satiation with and without exposure to 5.0 mg Zn/L over 6 weeks. No significant differences were observed in water quality variables due to feed rations and/or Zn exposure except unionized ammonia concentrations, which increased as feed ration increased with Zn exposure; its highest value was observed at fish fed up to satiation with Zn exposure. Fish performance was adversely affected by Zn exposure and feed unavailability. The performance was maximized when fish fed up to satiation without Zn exposure, whereas least performance was observed at starved fish with Zn exposure. Additionally, Zn exposure elevated significantly glucose, aspartate aminotransferase (AST), alanine aminotransferase (ALT), and creatinine values, while total protein and total lipids in fish sera were significantly lower with Zn exposure as compared to the control group. All these variables increased significantly with increasing feed ration size. The cortisol value was inversely affected by feed availability and directly proportioned to Zn exposure. It is also noticed that crude protein and total lipids contents in whole-fish body increased significantly with increasing feed ration and decreased significantly with Zn exposure. Total ash content and Zn residuals in whole-fish body were significantly highest in starved fish with Zn exposure. This study concluded that the feed availability adversely affected Zn toxicity where feed availability to appropriate ration could minimize the deleterious effect of Zn toxicity on Nile tilapia performance and health, and vice versa. Statement of relevance This paper presents data on the effect of feed availability on growth performance of Nile tilapia and its susceptibility to waterborne zinc toxicity via evaluating growth performance, whole-body measurements, and the biochemical response of Nile tilapia. Feeding fish up to satiation improved their welfare and reduced the impact of zinc toxicity and its bioaccumulation in whole-fish body and vice versa. Zinc exposure deteriorated the welfare of fasted fish or fish fed inadequate diet. © 2016


El-Boshy M.E.,Mansoura University | El-Ashram A.M.,Central Laboratory for Aquaculture Research | AbdelHamid F.M.,Mansoura University | Gadalla H.A.,Mansoura University
Fish and Shellfish Immunology | Year: 2010

Six hundred and forty Nile tilapia (Oreochromis niloticus) weighing 80-100 g were randomly allocated into eight equal groups (80 each). The first group acts as control. Groups S, B and L were fed on a ration supplemented with Saccharomyces cerevisiae, β-glucans and laminaran, respectively for 21 days. Groups M, MS, MB and ML were subjected throughout the experiment to sublethal concentration of mercuric chloride (0.05 ppm). Gps. MS, MB and ML were fed on a ration containing S. cerevisiae, β-glucan and laminaran respectively for 21 days. Fish were challenged with Aeromonas hydrophila (0.4 × 107 cells mL-1) via intra-peritoneal injection and the mortality rate was recorded up to 10 day post-challenge. The non-specific defense mechanisms, cellular and humoral immunity, beside the total and differential leukocytic count were determined. Lymphocyte transformation index, phagocytic activity percent, phagocytic index, total lymphocyte count, serum bactericidal activity and nitric oxide as well as the survival rate were insignificantly changed after 21 day in gps. MS&ML, when compared with mercuric chloride immune depressed group M. These parameters as well as the neutrophil adhesion, serum nitric oxide and survival rate were significantly increased in gp. MB when compared with gp. M. Meanwhile the cellular and humoral immunity beside the survival rate were significantly increased in groups S, B, L when compared with control group. It could be concluded that the whole yeast S. cerevisiae, β-glucan and laminaran can be used as immunostimulants for the farmed Nile tilapia. The β-glucans could be used in farmed Nile tilapia, under immune depressive stressful condition to increase their resistance to diseases. © 2010 Elsevier Ltd. All rights reserved.


Ahmad M.H.,Central Laboratory for Aquaculture Research | Abdel-Tawwab M.,Central Laboratory for Aquaculture Research
Aquaculture | Year: 2011

The use of medicinal plants for humans has been well known since the ancient civilizations, but their uses in fish diets are still limited. It is believed that the use of medicinal plants as natural feed additives is less toxic and safer than chemical ones. So, this study was conducted to evaluate the use of caraway seed meal (Carum carvi L.; CSM) as a feed additive on growth performance, feed utilization, and whole body composition of Nile tilapia, Oreochromis niloticus (L.). Five iso-nitrogenous (30.3% crude protein) and iso-caloric (4.5. kcal/g diet) diets were formulated to contain 0.0 (control), 5, 10, 15, or 20. g CSM/kg diet. Fish (3.6 ± 0.3. g) were distributed at a rate of 20 fish per 100-L aquarium and three aquaria have been assigned for each treatment. Fish were fed one of the tested diets at a rate of 4% of live body weight twice daily; six days a week for 12. weeks. The CSM supplementation enhanced fish growth over the control diet; the highest fish growth and feed utilization were obtained when fish fed on a diet containing 10. g CSM/kg diet. There were no significant changes in fish survival among the different treatments and its range was 98.5-100% suggesting that CSM had no toxic effect. Moreover, CSM has no impact on moisture and protein contents in whole fish. Total lipid increased significantly and total ash contents decreased significantly with increasing CSM levels. A dietary CSM level of 12.5. g/kg provided the best fish performance based on second-order polynomial regression analysis of growth parameters against dietary CSM levels. © 2011 Elsevier B.V.


Abdel-Tawwab M.,Central Laboratory for Aquaculture Research | Ahmad M.H.,Central Laboratory for Aquaculture Research | Khattab Y.A.E.,Central Laboratory for Aquaculture Research | Shalaby A.M.E.,Central Laboratory for Aquaculture Research
Aquaculture | Year: 2010

A 10-week feeding trial was conducted to assess the interaction between dietary protein level and fish weight on the growth, feed utilization, and physiological alterations of Nile tilapia, Oreochromis niloticus (L.). Fish were categorized into three weights; 0.4-0.5 g (fry), 17-22 g (fingerling), and 37-43 g (advanced juvenile). Diets containing 25, 35, or 45% crude protein (CP) were fed by triplicate to each fish weight. Fish growth, feed utilization, and protein turn-over were significantly affected by dietary protein level and fish weight, meanwhile their interaction significantly affected specific growth rate and protein efficiency ratio (PER) only. Unionized ammonia was significantly affected by dietary protein level, fish weight, and their interaction. Moreover, protein and lipid contents in whole-body of fish were significantly affected by dietary protein level and fish weight, while their interaction significantly affected total lipids content only. Ash content significantly differed with fish weight only. The optimum feed conversion ratio (FCR) was obtained with fry tilapia fed the 45%-CP diet; whereas, the poorest FCR was observed for advanced juveniles fed the 25%-CP diet. The lowest PER and protein productive value (PPV) values were obtained with the 45%-CP diet fed to advanced juveniles; whereas, the highest values were obtained with the 25%-CP diet fed to fry. The highest protein growth rate (PGR) was obtained with fry tilapia fed the 45%-CP diet, while the lowest one was obtained with advanced juvenile fed the 25%-CP diet. Hematological variables were significantly affected by protein level, fish weight, and their interaction except for serum lipids which was not significantly affected by the interaction. Activities of aspartate amninotransferase (AST) and alanine aminotransferase (ALT) in serum, liver, and muscles were significantly affected by dietary protein level and fish weight. The interaction significantly affected enzyme activities except for serum AST, which was not significant. The optimum growth of fry tilapia was obtained at 45% CP, while fingerling and advanced juvenile showed optimum growth performance with the 35%-CP diet. Excess protein in fingerling and advanced juvenile might be deaminated and used as energy source resulting in increased blood glucose, protein, and lipids as well as increased unionized ammonia in the environment. © 2009 Elsevier B.V. All rights reserved.


Yeasts used as a probiotic in fish diets could stimulate fish resistance against bacterial infection and could enhance the activities of digestive enzymes in fish guts. In addition to yeast importance, dietary protein is another important part in fish diets that should be carefully optimized to meet fish requirement. It is proposed that the yeast supplementation may enhance the dietary protein turnover and reduce the protein requirement for fish. Therefore, the interactive effects of dietary protein and yeast levels on the growth performance of Nile tilapia, Oreochromis niloticus (L.) fry and their challenge against Aeromonas hydrophila infection was evaluated. In the present study, ten experimental diets were formulated to contain either 35% or 45% crude protein (CP). For each protein level treatment, bakery yeast (Saccharomyces cerevisiae) was supplemented at 0.0, 0.50, 1.0, 2.0, or 5.0 g/kg diet. Fish (0.25-0.48 g) were distributed at a rate of 25 fish per 140-L aquarium. For each diet, triplicate aquaria were fed twice a day, 5 days a week for 12 weeks. Fish growth and feed utilization were significantly affected by either dietary protein or yeast levels alone, while no significant effect of their interaction was observed. The highest fish growth was obtained at 1.0-5.0 g yeast/kg diet at both protein levels; however, the fish performance at 45% CP was better than that fed on 35% CP diets. The optimum feed conversion ratio (FCR) was obtained when fish fed on 1.0-5.0 and 2.0-5.0 g yeast/kg diet at 35 and 45% CP, respectively. The cumulative fish mortality, after interperitoneal injection with A. hydrophila for 10 days, and bactericidal activity was significantly higher in fish fed 35% CP diets than those fed 45% CP diets. Both variables decreased significantly with the increase in yeast levels. The lowest bacterial count and bactericidal activity were obtained in fish fed 5.0 g yeast/kg diet irrespective to dietary protein levels. It could be concluded that the inclusion of live bakery yeast in practical diets could improve the growth performances, feed utilization, and physiological status of Nile tilapia fry and their challenge against A. hydrophila infection. Moreover, fish performance when fed 45% CP diet was better than those fed 35% CP diet. Based on these results, the most suitable yeast level for maximum Nile tilapia growth was determined to be 2.0 g yeast/kg diet with 45% CP diet; however, this level was recommended to stimulate their productive performance and enhances their resistance against A. hydrophila infection. © 2011 Springer Science+Business Media B.V.

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