IJA Volume 63, 2011

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    Comparison of Growth in Pike-Perch (Sander lucioperca) and Hybrids of Pike-Perch (S. lucioperca) × Volga Pike-Perch (S. volgensis)
    (Israeli Journal of Aquaculture - BAMIGDEH, 2011) Müller, T.; Bódis, M.; Urbányi, B.; Bercsényi, M.
    Growth of intensively cultured pike-perch Sander lucioperca (L.) and hybrids of pike-perch females × Volga pike-perch (S. volgensis Gmelin, 1789) males (1.75 g) were compared in a 35-day experiment. Fish were sorted into three groups (50 fish/aquarium): S. lucioperca grown separately (Group P), hybrids grown separately (Group H), and a mixed group of 25 S. lucioperca (Group Mp) grown together with 25 hybrids (Group Mh). The stocking density was 0.44 g/l. Final body weights were 6.83 g, 6.54 g, 5.17 g, and 4.84 g, and specific growth rates were 3.9%/day, 3.75%/day, 3.1%/day, and 2.89%/day, for groups Mp, P, Mh, and H, respectively. The weight, length, and specific growth rates of the S. lucioperca were significantly higher (p<0.05) than those of the hybrids, whether grown separately or together. The feed conversion rate of the hybrids grown separately was significantly higher (1.28 g/g) than all other groups. Further investigation is needed to study the growth performance of larger hybrids, to compare the hybrid with S. volgensis, and to investigate the possibility of cross hybridization.
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    Replacement of Fishmeal Using Poultry Offal Meal in Practical Feeds for Fry of the African Catfish (Clarias gariepinus)
    (Israeli Journal of Aquaculture - BAMIGDEH, 2011) Falaye, A.E.; Omoike, A.; Ajani, E.K.; Kolawole, O.T.
    A 70-day feeding trial was conducted to test the effect of partial replacement of fishmeal by poultry offal in the diet for fry of the African catfish, Clarias gariepinus. Four isonitrogenous rations containing replacement of 0 (control), 30%, 60%, or 90% fishmeal by poultry offal were fed to three replicate groups of C. gariepinus fingerlings (0.74 g). Growth performance and nutrient utilization of the fish were evaluated based on weight gain, protein intake, protein efficiency ratio, specific growth ratio, gross efficiency of food conversion, and carcass analysis. The average weight gains of fingerlings fed the control (2.43 g) and 30% replacement diet (2.31 g) were higher than in fish fed the 60% (2.09 g) and 90% (2.0 g) replacement diets. The feed conversion ratio (1.48-1.62) was lowest in fish fed the control diet and highest in fish fed the 90% replacement diet. The specific growth rate, protein efficiency ratio, and apparent net protein utilization significantly decreased (p<0.05) as the level of dietary poultry offal increased. It was concluded that replacement of up to 30% fishmeal by chicken offal meal enhances growth performance of C. gariepinus fry.
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    Effect of Three Diets on Growth and Survival Rates of African Catfish Heterobranchus bidorsalis Larvae
    (Israeli Journal of Aquaculture - BAMIGDEH, 2011) Alla, Yao Laurent; Célestin, Ble Melecony; Célestin, Atse Boua; Tidiani, Kone
    Investigations are underway in the Centre de Recherches Océanologiques d’Abidjan (Côte d’Ivoire) to find whether the catfish (Heterobranchus bidorsalis) could be an interesting aquaculture species. Within this framework a 28-day aquarium culture feeding trial was conducted to investigate the effects of three diets (Artemia salina nauplii, beef brain enriched with vitamins, and a compound food) on the growth and survival rates in 2-day post hatch H. bidorsalis. The feeding experiments started after the yolk sac of the larvae was absorbed (initial mean weight = 2.03±0.38 mg). Larvae fed Artemia nauplii had a higher growth rate (final mean weight = 708.60±411.61 mg] than those fed beef brain (381.81±118.88 mg) or compound food (102.72±48.09 mg). Conversely, the beef brain diet yielded a better survival rate (70.47±9.48%) than the Artemia nauplii (38.72±7.74%) or the compound diet (5.37±2.24%). Thus, beef brain can be used as a starter food for larval rearing of H. bidorsalis.
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    Effects of Dietary Pelargonium sidoides Extract on Growth Performance in Common Carp, Cyprinus carpio
    (Israeli Journal of Aquaculture - BAMIGDEH, 2011) Turan, Funda; Gezer, Armağan; Bircan-Yildirim, Yasemin
    The effects of graded dietary supplementation of Pelargonium sidoides extract on growth performance, feed utilization, and body composition in common carp, Cyprinus carpio, were preliminarily evaluated. Fish (0.67±0.05 g) were fed experimental diets containing 0, 1, 3, or 5 ml/100 g P. sidoides extract for 90 days. Growth rate significantly (p<0.05) increased in carp fed supplemented diets. The specific growth rate ranged from 2.87±0.09 in the control to 3.41±0.11 in fish fed the diet supplemented with 5 ml P. sidoides. The feed conversion ratio, protein efficiency ratio, and apparent net protein utilization were significantly better in groups fed diets with 3 or 5 ml P. sidoides extract than in the control or 1 ml group. The highest protein content (19.65%) was obtained with 3 ml supplementation. The present study shows that P. sidoides extract has a positive effect on carp growth and feed utilization with no apparent effects on health status.
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    Population Growth of Bosmina longirostris Fed Chlorella vulgaris and Scenedesmus subspicatus in Different Densities
    (Israeli Journal of Aquaculture - BAMIGDEH, 2011) Ertan, Ömer Osman; Güçlü, Zekiye; Erdoğan, Ömer; Savaş, Sevgi; Gülle, İskender
    In this study, the effects of the different densities of Chlorella vulgaris (0.05 x 106, 0.1 x 106, 0.2 x 106, 0.4 x 106, or 0.8 x 106 cells/ml) and Scenedesmus subspicatus (0.05 x 106, 0.1 x 106, 0.2 x 106, or 0.4 x 106 cells/ml) on culture of the water flea, Bosmina longirostris, were investigated. The experiment was carried out in a photoperiod of 16 h light:8 h dark at 25±1°C. At the beginning of the experiment, one B. longirostris individual (<24 h old) was put into each vessel, and the number of individuals and rate of population increase were determined for 30 days. Increasing the food density increased the number of individuals and the rate of population. The maximum number of B. longirostris individuals (7.1±2.08 ind/ml) and maximum rate of population increase (0.2±0.004/day) was in the group fed 0.2 x 106 cells/ml S. subspicatus. The effect on the number of the individuals was statistically significant (p<0.05).
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    Effect of Dietary Canola Oil Level on Fatty Acid Composition of Rainbow Trout (Oncorhynchus mykiss L.)
    (Israeli Journal of Aquaculture - BAMIGDEH, 2011) Dernekbaşi, Seval; Karayücel, İsmihan; Öksüz, Abdullah
    The effects of different levels of dietary canola oil on fatty acid composition of rainbow trout (Oncorhynchus mykiss) were investigated. Five experimental diets with equal protein (47%) and lipid (17%) contents were formulated for rainbow trout with a mean weight of 119±0.17 g. Canola oil was used to replace 0, 25%, 50%, 75%, or 100% of the fish oil in the control diet. Fish were fed twice daily to satiation for 70 days. At the end of the study, fatty acid compositions in the trout body mirrored the fatty acid compositions of the experimental diets. The highest fatty acids were palmitic acid (C16:0), oleic acid (C18:1n-9), linoleic acid (C18:2n-6), and docosahexaenoic acids (C22:6n-3). The study showed that, under our test conditions, canola oil can replace 100% of fish oil with no negative effect on the chemical or fatty acid composition of rainbow trout.
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    Improving Salinity Tolerance in Tilapias: Past Experience and Future Prospects
    (Israeli Journal of Aquaculture - BAMIGDEH, 2011) Hulata, Gideon; Cnaani, Avner
    With increasing scarcity of fresh water available for aquaculture, especially in arid regions, development of tilapias that tolerate high salinity would increase fish (and hence, animal protein) production. We review culture practices, nutrition, physiology, and genetics, and propose approaches to improving salinity tolerance in tilapias. Physiological studies of biochemical pathways underlying phenotypic differences in salt tolerance can lead to genetic studies of intra and interspecific variation. Molecular technology can lead to studies on osmoregulation-related biochemical pathways, for which the euryhaline tilapia is an attractive model. Functional genomics and proteomics are powerful tools for studying the molecular bases of environmental adaptation and metabolic connections to osmoregulatory physiology. Both provide avenues for discovering novel pathways related to osmoregulation with relevance to aquaculture. Dietary supplementation with NaCl and optimized acclimation protocols are immediate and practical ways to improve salt tolerance. Inter-specific variation in salinity tolerance may be used to select salt-tolerant species and develop salt-tolerant hybrids. In the long term, quantitative trait loci associated with, or genes involved in, saltwater tolerance may facilitate marker-assisted or gene-assisted selection for this trait in tilapia.
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    The Effects of Light Intensity and Color on Aggressive Interactions in the Dusky Kob, Argyrosomus japonicus
    (Israeli Journal of Aquaculture - BAMIGDEH, 2011) Timmer, Rowan; Magellan, Kit
    The dusky kob, Argyrosomus japonicus, is highly susceptible to stress under culture conditions. Such stress frequently involves a high degree of aggression, leading to cannibalism. Here, the effects of light intensity and color on the frequency of aggressive interactions and the time that passes between presentation of food and food first being eaten (feeding latency) in this species were examined. Aggression was lowest when fish were maintained in partial shade and highest in red light. Feeding latency was not affected by light treatment. The results can aid the aquaculture industry in determining the optimal light intensity for minimizing aggressive behavior in A. japonicus.
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    Efficacy of an Inactivated Vaccine and Nutritional Additives Against White Spot Syndrome Virus (WSSV) in Shrimp (Penaeus monodon)
    (Israeli Journal of Aquaculture - BAMIGDEH, 2011) Amar, Edgar C.; Faisan, Joseph P. Jr.
    Although the immune system of shrimps is not comparable to that of vertebrates, shrimps can acquire protection against pathogenic challenge by building up immunity. In this study, formalin-inactivated virus (FIV) was administered by injection, bath-immersion, or orally to determine levels of vaccination-mediated protection against the pathogenic white spot syndrome virus (WSSV). Diets supplemented with alfalfa, methyl sulfonyl methane (MSM), or wheat grass were provided with or without FIV. Shrimp injected with FIV and challenged 3, 15, or 30 days after vaccination had cumulative and relative survivals of 83%, 67%, and 33%, respectively. Survival of shrimp challenged by bath-immersion 3-45 days after vaccination by immersion was significantly higher than in the unvaccinated control. Orally vaccinated shrimp challenged by bath-immersion were partially protected up to 45 days after vaccination (cumulative survival 63.7%, relative 61.7%) but not til 60 days after vaccination (cumulative 8%, relative 3.2%). Survival of unvaccinated shrimp challenged by bath-immersion improved when shrimp were fed a diet supplemented with wheat grass or MSM, but not alfalfa. Survival was further enhanced when FIV was provided together with diets supplemented with wheat grass (cumulative 72.7%, relative 94.8%) or MSM (cumulative 73.3%, relative 96.3%).
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    The Effects of Different Carotenoid Sources on Skin Pigmentation of Goldfish (Carassius auratus)
    (Israeli Journal of Aquaculture - BAMIGDEH, 2011) Yeşilayer, Nihat; Aral, Orhan; Karsli, Zafer; Öz, Meryem; Karaçuha, Ali; Yağci, Feraye
    The aim of this study was to investigate the effect of different carotenoid sources on goldfish (Carassius auratus) skin pigmentation. The value of goldfish depends on the intensity of the skin color. In the red variety of goldfish, an orange-red hue is desirable. Juvenile goldfish were fed one of five diets for five months to determine the effects of carotenoids on skin pigmentation, growth, feed efficiency, and survival: (1) astaxanthin (carophyll pink at 75 mg/kg), (2) canthaxanthin (carophyll red at 75 mg/kg), (3) Gammarus spp. (75 mg/kg), (4) Oleoresin paprika (180 mg/kg), and (5) an unsupplemented control. Growth and feed efficiency did not significantly differ among groups. Initial and final samples of head skin were measured by colorimetric analysis for lightness (L*), redness (a*), yellowness (b*), hue (Hºab), and chroma (Cab*). The best red color (a* and Hºab) was obtained with the astaxanthin, canthaxanthin, and paprika diets.
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    Partial Purification and Characterization of the Inhibitory Substance of Bacillus subtilis against Common Bacterial Fish Pathogens
    (Israeli Journal of Aquaculture - BAMIGDEH, 2011) Nayak, S.K.; Mukherjee, S.C.
    The present investigation was carried out to study the active component of Bacillus subtilis, a gastrointestinal bacterium of mrigal (Cirrhinus mrigala) that shows inhibitory activity against a wide range of fish pathogens. The bacterium was found to inhibit all the fish pathogens and an extra cellular protein fraction (ECP) of 5-10 kD was found to be the active component responsible for inhibitory activity. The component was heat stable (60°C for 1 h) and a change in pH had no effect on the antibacterial activity. The protein fraction was sensitive to trypsin, chymotrypsin, lysozyme, and proteinase K at 2.5 mg/ml and resistant at 0.1 and 0.5 mg/ml. The present investigation confirmed that the active component of the B. subtilis responsible for antibacterial activities against common fish pathogens is a low molecular weight protein fraction (5-10 kD). A protein or peptide with such a low molecular weight has the potential to serve as an alternative health management strategy for combating disease in aquaculture.
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    Effect of Glycerol on Fertility of Cryopreserved Grass Carp (Ctenopharyngodon idella) Sperm
    (Israeli Journal of Aquaculture - BAMIGDEH, 2011) Bozkurt, Yusuf; Yavaş, İlker; Öğretmen, Fatih; Sivaslıgil, Buğra; Karaca, Fikret
    This research investigated the effect of adding glycerol to different ionic extenders on motility and fertilizing ability of frozen-thawed sperm of grass carp (Ctenopharyngodon idella) under hatchery conditions. Semen was collected by abdominal stripping from adult males and diluted to a ratio of 1:3 in Kurokura I or Kurokura II extender containing 10%, 15%, or 20% glycerol. Diluted semen was packaged in 0.5-ml straws and left to equilibrate for 30 min at 4°C. Following equilibration, the straws were exposed to liquid nitrogen vapor for 10 min and plunged into liquid nitrogen (-196°C). Straws were thawed in a water bath at 30°C for 10 s to determine the post-thaw motility and movement duration. The spermatozoa:egg ratio in fertilization experiments was 1 x 105:1. The highest mean fertilization rate (95.63±0.52; p>0.05) was obtained with semen frozen in Kurokura I extender containing 10% glycerol. Results indicate that grass carp sperm can be successfully cryopreserved with ionic extenders containing glycerol at 10-20%.
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    Evaluation of Autotrophic and Heterotrophic Microcosm-based Systems on the Production Response of Litopenaeus vannamei Intensively Nursed without Artemia and with Zero Water Exchange
    (Israeli Journal of Aquaculture - BAMIGDEH, 2011) Becerra-Dórame, M.J.; Martínez-Córdova, L.R.; Martínez-Porchas, M.; Lopez-Elías, J.A.
    An experiment was conducted for 28 days to evaluate the productive response of the Pacific white shrimp (Litopenaeus vannamei) postlarvae, intensively nursed in autotrophic or heterotrophic microcosm-based treatments, without Artemia and zero water exchange. The autotrophic system was based on the promotion of microalgae as the main primary producers. The heterotrophic system was based on the promotion of bacteria as the main primary producers. The control was fed a conventional diet. Bioflocs and biofilms were used to promote biota in the autotrophic and heterotrophic systems. There were no differences in temperature, salinity, or DO among treatments. The chlorophyll a concentration and microalgae density were much greater in the control and autotrophic system than in the heterotrophic. The concentration of heterotrophic bacteria was significantly higher in the heterotrophic than in the autotrophic system and control. Individual weight gain was higher in the control (81±2 mg) and heterotrophic (77±8 mg) treatments than in the autotrophic (58±10 mg) but survival was better in the autotrophic (86%) than control (77%) and heterotrophic (76%) treatments. Final biomass was statistically similar in all treatments, as well as the feed conversion ratio which ranged from 0.65 (heterotrophic) to 0.69 (autotrophic). The increased natural productivity caused a positive productive response in the shrimp postlarvae. Such strategies can be an adequate alternative when Artemia is unavailable.
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    Effects of L-Carnitine on Growth of Individually Cultured Cladoceran, Moina micrura
    (Israeli Journal of Aquaculture - BAMIGDEH, 2011) Savas,S.; Erdogan, O.; Cicek, N.L.
    The cladoceran, Moina micrura, is a potential alternative live food for fish larvae. The effects of L-carnitine enrichment on first reproduction age, population density, and growth rate in M. micrura were determined. The cladocerans were enriched at 10 levels of L-carnitine (0, 0.001, 0.01, 0.1, 1, 10, 100, 500, 1000, and 1500 mg/l) dissolved in 30 ml Chlorella vulgaris culture medium for 17 days. The first reproduction age was stimulated by the supplemental L-carnitine. The population density was highest in the 1 mg/l treatment. The highest population growth rate was obtained in the 10 mg/l treatment, but it did not differ from the growth rate in the 0.1, 1, or 100 mg/l treatments. Consequently, the optimum L-carnitine concentration for M. micrura is 1 mg/l. Results suggest that L-carnitine can be a positive factor in enhancing the use of M. micrura as an alternative live food for fish larvae.
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    Dietary Zinc and Cobalt Requirements of Fry of Seabass (Lates calcarifer) and Catfish (Clarias batrachus)
    (Israeli Journal of Aquaculture - BAMIGDEH, 2011) Sapkale, P.H.; Singh, R.K.
    An 8-week experiment was conducted to determine the cobalt and zinc requirements of fry of seabass (Lates calcarifer) and catfish (Clarias batrachus). Fifteen diets for each fish were formulated with varying concentrations of cobalt and zinc, alone and in combination. The control diet was not supplemented with cobalt or zinc. The diets for L. calcarifer had 45% protein, while the diets for C. batrachus had 30%. The diet that produced the best growth for L. calcarifer (1100%) contained 2.5 mg Co + 45 mg Zn/kg diet and for C. batrachus (1149%) contained 5 mg Co + 30 mg Zn/kg. Growth in the control L. calcarifer was 738% and in the control C. batrachus was 428%. For both species, the food conversion ratios were best in the above diets, 1.17±0.52 for L. calcarifer and 1.40±0.62 for C. batrachus as opposed to 1.89±0.39 and 2.54±0.61 for the respective controls.
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    Effect of Feeding Frequency and One Day Fasting on Tilapia (Oreochromis niloticus) and Water Quality
    (Israeli Journal of Aquaculture - BAMIGDEH, 2011) Villarroel, Morris; Alavriño, José Mario R.; López-Luna, Javier
    The aim of this study was to investigate the effects of different feeding frequencies and one day fasting on the quality of tank water in a recirculation system and on the growth, body composition, and welfare of juvenile Nile tilapia (Oreochromis niloticus). One hundred and twenty juveniles (24±4.2 g) were fed two or four times a day, with or without a one-day fast every fourth day. Fish that were fed two or four times every day grew more than fish that fasted once a week, but there were no significant differences in food conversion rate or specific growth rate among the four treatments. Regarding body composition, fish fed four times a day, whether fasted or not, had a higher percentage of fat, while the percentage of protein was highest in fish fed four times a day with a one-day fast every fourth day. Plasma cortisol levels at the end of the trial were similar between frequencies, suggesting little effect of feeding frequency on stress level. Electrical conductivity in tank water was highest in the twice a day/fasting group and related to higher sodium (Na+) and chloride (Cl-) levels. Overall, results suggest that fasting one day a week does not affect growth efficiency and that tilapia adjust well to relative changes in feeding frequency.
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    Growth and Feed Efficiency in Mangrove Red Snapper, (Lutjanus argentimaculatus Forsskal 1775) Fed Practical Diets Supplemented with L-ascorbyl-2-monophosphate-Mg
    (Israeli Journal of Aquaculture - BAMIGDEH, 2011) Catacutan, Mae R.; Pagador, Gregoria E.; Doyola-Solis, Ellen; Teshima, Shinichi; Ishikawa, Manabu
    Growth and feed efficiency were determined in red snapper, Lutjanus argentimaculatus (Forsskal 1775), fed diets containing L-ascorbyl-2-monophosphate-Mg (AMP). Fish (13.39±0.08 g) were fed a practical diet without vitamin C supplement for four weeks then stocked in twelve 650-l tanks at 30 fish/tank and fed one of four practical diets containing AMP at 0, 60, 180, or 540 mg/kg dry diet for 17 weeks. Survival rates in all treatments were similar (88.9-98.9%). Fish fed the 0 or 540 ppm diets had inferior final average weights, protein efficiency ratios, and feed conversion ratios than fish fed the 60 or 80 ppm diets (p<0.05). Growth of fish fed the 0 or 540 ppm diets slowed down on day 60 and fish fed the AMP-free diet exhibited clinical signs of vitamin C deficiency with a soft body and a significantly high (p<0.05) hepatosomatic index. Ascorbic acid in brain and liver tissues rose with the level of dietary AMP. Fish fed the 540 ppm diet had significantly lower hematocrit (p<0.05) than fish fed the 60 or 180 ppm diets. Histological analysis of the liver and kidney of fish fed the 180 and 540 ppm diets showed changes indicative of possible toxic effects. Based on growth, feed efficiency, tissue histology, and hematocrit level, AMP at 540 ppm is toxic to snapper. Thus, supplementation of 60 ppm AMP or its equivalent 26 ppm ascorbic acid in practical diets for red snapper promotes optimum growth and feed efficiency and prevents vitamin C deficiency symptoms.
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    Replacement of Fishmeal by Rapeseed Protein Concentrate in Diets for Common Carp (Cyprinus carpio L.)
    (Israeli Journal of Aquaculture - BAMIGDEH, 2011) Slawski, Hanno; Adem, Halime; Tressel, Ralf-Peter; Wysujack, Klaus; Koops, Udo; Schulz, Carsten
    The potential of rapeseed protein concentrate as an alternative to fishmeal in diets for common carp (initial average weight 26.7±0.8 g) was evaluated. Triplicate groups of fish were fed isonitrogenous (40.4±0.2% crude protein) and isocaloric (21.4±0.1 kJ/g) experimental diets with 0%, 33%, 66%, or 100% replacement of fishmeal by rapeseed protein concentrate. At the end of the 56-day feeding period, growth parameters and feed efficiencies did not significantly differ between fish fed the 0% and 33% diets. The 66% and 100% replacement diets led to reduced feed intake and feed efficiency, resulting in lower growth performance. It appears that the taste and amino acid profile of these diets were negatively affected by the high inclusion levels of rapeseed protein concentrate. In conclusion, rapeseed protein concentrate can effectively replace 33% of the fishmeal in diets for carp without using palatability enhancers or amino acid supplements.
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    Offshore Farming of the Mediterranean Amberjack (Seriola dumerili) in the Northeastern Mediterranean
    (Israeli Journal of Aquaculture - BAMIGDEH, 2011) Yilmaz, Erdal; Şereflişan, Hülya
    The growth rate, survival, and feeding parameters of Mediterranean amberjack (Seriola dumerili Risso, 1810) cultivated in offshore cages in the Gulf of İskenderun (Hatay, Turkey) were investigated from July 2006 to March 2008. Two offshore cages (339 m3) were placed at a depth of 10 m in a sheltered area 500 m off the coast. Juveniles (101.97±14.54 g), caught with seine nets 400-1200 m from the coast, were stocked in the cages at 250 per cage. Fish in one cage, Group A, were fed commercial pellets for all 20 months whilst fish in the second cage, Group B, were fed pellets for the first 16 months and frozen sardines for the following four. The mean live weight, survival, feed conversion ratio, daily feed consumption, and water quality parameters were recorded monthly. Group B reached a significantly (p<0.05) greater weight (2785.00±64.91 g) than Group A (2441.14±38.13 g). Food conversion ratios ranged 1.16-2.46 for group A and 1.10-2.28 for group B, low when compared with other studies on amberjacks in the Mediterranean. Average mortality was 25%, due to a Zeuxapta seriolae (Monogenea: Heteraxinidae) infection in December 2006 (20%) and fish handling for measurement in June 2007 (~5%). The farmed amberjacks had significantly higher protein and lipid contents than their wild counterparts at the end of the 20-month feeding period. Amberjacks found frozen sardines more appealing than pellets, especially during the winter. In conclusion, it is advised to feed Mediterranean amberjack frozen sardines or other trash fish during the winter grow-out period. Their rapid growth rate, as well as their adaptability to farming, make offshore net cages a promising system for the aquaculture of this species.
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    Effect of Dietary Selenium Supplementation on Cirrhinus mrigala (Hamilton, 1822) Reared in Copper and/or Cadmium Contaminated Water
    (Israeli Journal of Aquaculture - BAMIGDEH, 2011) James, Raja
    The effect of selenium supplementation at 0, 75, 150, 225, and 300 mg/kg diet on reduction of copper and/or cadmium toxicity was studied in a freshwater cultivated carp, Cirrhinus mrigala. Food utilization, selected hematological parameters, oxygen consumption, and metal concentrations in the fish body and fecal matter were analyzed. The 96-h LC50 values for C. mrigala were 0.126 ppm for copper exposure, 0.563 ppm for cadmium, and 0.123 ppm for exposure to both metals simultaneously. Sublethal exposures to the metals significantly reduced consumption and growth rates, hematological parameters, and oxygen consumption in fish fed the unsupplemented diet. Equitoxic exposure of copper and cadmium together drastically reduced the physiological parameters as compared to individual exposure to either one of the metals. However, dietary selenium supplementation significantly improved the tested physiological parameters and reduced the metal burden in the fish body. Metal elimination from the body took place through the feces. Supplementation of 75 and 225 mg selenium per kg diet was required to reduce copper and cadmium toxicity when the metals existed individually in the environment. However, 300 mg selenium per kg diet was required to reduce toxicity when both metals were present together in the environment.