IJA Volume 62, Issue 1, 2010

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    Soybean Meal and Rendered Animal Protein Ingredients Replace Fishmeal in Practical Diets for Sea Bass
    (Israeli Journal of Aquaculture - BAMIGDEH, 2010) Altan, Ozgur ; Gamsiz, Kutsal ; Korkut, Ali Yildirim
    A 180-day feeding trial was carried out in net cages to examine replacement of fishmeal with soybean meal supported by meat/bone meal and blood meal in practical diets for sea bass (Dicentrarchus labrax L. 1758). Triplicate groups of fish (initial body weight 110 g) were fed one of four isonitrogeneus (crude protein 46%) and isolipidic (10%) diets. A commercial sea bass diet containing 64% fishmeal as the sole animal protein served as the control. The other three diets contained 0, 20%, or 35% fishmeal and the reduced fishmeal was replaced by different levels of soybean meal, meat/bone meal, and blood meal. The final body weight of fish fed the diet containing 20% fishmeal, 50% soybean meal, 10% meat/bone meal, and 4% blood meal was significantly higher than that of the other three treatments. Results indicate that fishmeal can be reduced to 20% when soybean meal, meat/bone meal, and blood meal are used together in the diet.
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    Growth and Survival of African Catfish (Clarias gariepinus) Larvae Fed Decapsulated Artemia, Live Daphnia, or Commercial Starter Diet
    (Israeli Journal of Aquaculture - BAMIGDEH, 2010) Olurin, K.B. ; Oluwo, A.B.
    The effects of three diets (decapsulated Artemia, live Daphnia spp., and commercial starter diet) on the growth and survival of Clarias gariepinus larvae were investigated in the laboratory for seven days using a completely randomized block design. Larvae were hatched by the hypophysation technique and, immediately after resorption of the yolk sac, randomly distributed into nine tanks at a stocking rate of 180 larvae per experimental plastic tank. Triplicate groups were fed treatment diets ad libitum twice daily, in the morning and in the evening. The highest growth values were obtained in larvae fed decapsulated Artemia (p<0.05), while the survival rate was similar in fish fed decapsulated Artemia and live daphnia. It is concluded that feeds of animal origin are more suitable for first feeding of C. gariepinus larvae than inert diets.
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    Induction of All-triploid Japanese Flounder (Paralichthys olivaceus) by Cold Shock
    (Israeli Journal of Aquaculture - BAMIGDEH, 2010) Xu, Tian-jun ; Chen, Song-Lin
    Cold shock is a useful method of inducing triploidy in some fish species. In this paper, triploidy in Japanese flounder (Paralichthys olivaceus) was induced by applying cold shocks of 3°C, three or four minutes after fertilization, for 15, 25, 35, 45, 55, or 65 min. Ploidy of fry was analyzed using a ploidy analyzer. Survival was lower in treatments shocked at four minutes than in treatments shocked at three minutes after fertilization, and decreased as the duration of the cold shock increased. The abnormality rate increased with the shock duration. The best results were achieved in the treatment shocked three minutes after fertilization for 25 min, resulting in 100% triploidy with the highest survival rate (93.27%) and one of the lowest abnormality rates (15.87%). This study shows that cold shock is a highly effective method for inducing triploidy in the Japanese flounder.
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    Effects of Selected Levels of Water pH on the Growth and Survival of Swordtail (Xiphophorus helleri) Larvae
    (Israeli Journal of Aquaculture - BAMIGDEH, 2010) Sapkale, P.H. ; Singh, R.K. ; Desai, A.S.
    Larvae of swordtail (Xiphophorus helleri) were exposed to pH levels of 5.5, 6.0, 7.0, 8.0, and 8.5 to study growth and survival under laboratory conditions for 42 days. The larvae were fed formulated dry pellets at 7% of their body weight. The growth and survival rates were highest at pH 8.0 and 8.5, while mortality was complete at pH 5.5. In all treatments, the specific growth rate was higher in the first week and decreased in subsequent weeks. Thus, for swordtail larvae, the pH of the water should be between 8.0 and 8.5.
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    Detection of KHV in Freshwater Mussels and Crustaceans from Ponds with KHV History in Common Carp (Cyprinus carpio)
    (Israeli Journal of Aquaculture - BAMIGDEH, 2010) Kielpinski, Maciej ; Kempter, Jolanta ; Panicz, Remigiusz ; Sadowski, Jacek ; Schütze, Heike ; Ohlemeyer, Stefanie ; Bergmann, Sven M.
    Characterization of asymptomatic KHV carriers may help understand virus transmission and storage. Such information allows farmers to minimize KHV on farms where this virus is present, also in common carp (Cyprinus carpio) monocultures. As asymptomatic KHV carriers, freshwater mollusks from the Unionidae family (swan mussels, Anodonta cygnea) and crustaceans from the Gammaridae family (scud, Gammarus pulex) were studied because of their unique method of feeding by accumulating bacterial and viral particles. The KHV genome was detected by nested PCR and confirmed by PCR recognizing the KHV glycoprotein gene in ORF 56 (KHV-U). Both PCR and nested PCR, which recognize the KHV thymidine kinase gene, always produced negative results in the swan mussels and scud samples.
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    Effect of Dietary Supplementation of Spirulina on Growth and Phosphatase Activity in Copper-Exposed Carp (Labeo rohita)
    (Israeli Journal of Aquaculture - BAMIGDEH, 2010) James, Raja
    The impact of spirulina supplementation at 0, 2, 4, 6, or 10% on the alleviation of copper toxicity was studied in the freshwater cultivable carp, Labeo rohita. Evaluation was based on selected food utilization parameters and phosphatase activities. Copper concentrations in the aquatic medium, selected body tissues, and fecal matter were analyzed to determine the mechanism of toxicity reduction. Dietary supplementation of spirulina significantly improved the tested physiological and biochemical parameters and reduced the metal burden in tissues. Reduction of metal toxicity seems to be achieved via elimination of metal through feces. A significant positive correlation (r = 0.714; p<0.01; n = 18) was obtained between supplementation of dietary spirulina and copper defecation. The addition of 4% spirulina was optimum since this dose produced the maximum elimination of copper from the body and better physiological and biochemical parameters. The treatment period (21 days) was not sufficient for complete removal of the copper. Therefore, a longer period of supplementation is recommended.
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    Identification and Genotyping of Vibrio ordalii: A Comparison of Different Methods
    (Israeli Journal of Aquaculture - BAMIGDEH, 2010) Akayli, T. ; Timur, G. ; Albayrak, G. ; Aydemir, B.
    The phenotypical, serological, and molecular identification of Vibrio ordalii isolates recovered from diseased gilthead sea bream (Sparus aurata) in the Mediterranean area were investigated. Most isolates had similar phenotypic characteristics, but some showed small differentiation in biochemical analysis. Both slide agglutination and enzyme linked immunosorbent assay (ELISA) showed that the isolates were antigenically homogeneous and no different serotypes were detected. SDS-PAGE analysis showed that the structure of lipopolysaccharide (LPS) was heterogeneous, that outer membrane proteins (OMP) display homogeneous grouping protein banding patterns, and that the LPS profile of the isolates had different banding patterns. However, random amplified polymorphic DNA (RAPD) analysis revealed genetic variation (up to 90.4%) among isolates of the same species.
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    Physiological Stress Responses in Strains of the Gilthead Sea Bream (Sparus aurata)
    (Israeli Journal of Aquaculture - BAMIGDEH, 2010) Gorshkov, Sergei ; Gorshkova, Galina ; Ron, Benny
    In this study we examined the physiological responses of different strains of gilthead sea bream (Sparus aurata) to chronic and acute stress factors. Blood glucose levels, hematocrit, and lactate concentrations were examined in yearlings of different strains of gilthead sea bream subjected to different stress situations. In the first experiment, fish of the Ardag and ‘ebony’ strains were kept 45 days in moderate (35-45 kg/m3) or high (70-90 kg/m3) density. There were no significant effects on the blood glucose level but, at both densities, hematocrit was significantly higher in the Ardag strain (33.2±3.0% at moderate and 44.5±1.6% at high) than in the ebony strain (22.0±3.0% and 19.9±2.7%, respectively). The interaction of ‘strain’ and ‘crowding’ was highly significant, suggesting that hematocrit may respond differently in each strain to crowding. In the second experiment, we examined the effects of acute stress (handling without anesthesia) among four strains representing Mendelian mutations that affect body coloration in gilthead sea bream: ebony, ‘white’, ‘yellow’, and the normally pigmented Ardag. Significant variations in the glucose and lactate concentrations suggest that genotypes of gilthead sea bream may have heritable differences in their physiological responses to stress factors.