IJA Volume 61, Issue 1, 2009

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    Canola Meal as an Alternative Protein Source in Diets for Fry of Tilapia (Oreochromis niloticus)
    (Israeli Journal of Aquaculture - BAMIGDEH, 2009) Yigit, Nalan Ozgur ; Olmez, Murtaza
    Canola meal was used to replace fishmeal protein in diets for fry of tilapia (Oreochromis niloticus L. 1758) at rates of 0 (control), 10%, 20%, 30%, 40%, and 50%. The diets contained approximately 30% crude protein and 3000 kcal/kg digestible energy. The fry were fed 90 days and the growth, feed conversion ratio, protein efficiency ratio, hepatosomatic index, reno- somatic index, and body composition were determined. The final weight (5.12 g) and feed intake (7.99 g) of fry fed the 10% diet did not significantly differ from those of the control. Weight gains declined beyond this replace- ment level, probably because of increased levels of antinutritional factors, particularly glucosinolates. Whole body percentages for moisture, crude lipid, crude protein, and ash were unaffected by the dietary treatment. Re- sults indicate that protein from canola meal can replace up to 10% of protein from fishmeal in diets for tilapia fry.
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    Spawning Induction in the Carp: Past Experience and Future Prospects - A Review
    (Israeli Journal of Aquaculture - BAMIGDEH, 2009) Yaron, Z. ; Bogomoinaya, A. ; Drori, S. ; Biton, I. ; Aizen, J. ; Kulikovsky, Z. ; Levavi-Sivan, B.
    Most fish in aquaculture either fail to breed in captivity or their spawning occurs sporadically and late in the season. This is mainly due to the lack of natural cues in captivity, which leads to dysfunction of the endocrine axis regulating oocyte maturation and ovulation. Hypophysation as a remedy for this situation in fish has been employed in aquaculture since the 1930s and is still widely practiced. However, using crude pituitary homogenates in local hatcheries has frequently ended in failures that were attributed to the incon- sistent potency of the injected material and the unknown ovarian stage of the recipient fish. Since the mid 1980s, hypophysation has improved through the introduction of a standardized dry carp pituitary extract in which the luteinizing hormone (LH) content and activity have been calibrated (cal- ibrated carp pituitary extract = CCPE). Induction of spawning, however, is successful mainly in female cohorts in which 65% or more of the oocytes in an ovarian biopsy have migrating germinal vesicles. Further, due to decreasing quantities of industry-processed common carp and the expan- sion of ornamental carp production (koi and goldfish), the growing demand for CCPE could not be met, and an alternative had to be found. A hypo- thalamic approach, introduced into Israeli aquaculture in 1993 (called Dagin), combines a superactive analog of sGnRH (10 μg/kg), with the water-soluble dopamine (D2) receptor antagonist, metoclopramide (20 mg/kg). The progress of oocyte maturation in ovarian biopsies has been studied in parallel with changes in levels of LH, estradiol, and the matura- tion-inducing steroid (MIS; 17α, 20β, dihydroxy-4-pregnene-3-one). The hormone profile indicated that the gradual increases in LH and MIS follow- ing a single administration of Dagin were similar to those in fish treated with priming and resolving doses of CCPE. This would explain why Dagin is effective even when only a single injection is given, saving labor and reduc- ing handling stress. CCPE and Dagin were tested in parallel on common carp in a commercial hatchery. The spawning ratio and embryo viability were similar, although the latency between injection and ovulation was con- siderably longer and more variable in Dagin-treated than in CCPE-treated carp. It is recommended to use CCPE at the beginning and end of the spawning season when the LH content in the pituitary is low, and Dagin in mid-season and in field spawning. Future prospects raise the possibility that by employing molecular tools, a recombinant carp LH will be produced that will have the regular and expected potency of the hypophyseal approach without the risk of spreading pathogens from donor fish to broodstock. Work along this line is currently in progress.
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    Effect of Photoperiod on Growth of Trout (Oncorhynchus mykiss) in Cold Ambient Sea Water
    (Israeli Journal of Aquaculture - BAMIGDEH, 2009) Türker, Ali
    The effects of four photoperiod regimes on growth performance of the rain- bow trout (Oncorhynchus mykiss W.) in cold ambient seawater conditions were compared in indoor seawater tanks (salinity 18 g/l; 6-8°C) in Janu- ary-February. The photoperiods were the natural photoperiod (10 h light: 14 h dark), 20 h light:4 h dark, 16 h light:8 h dark, and 0 h light:24 h dark. Fish were fed a diet consisting of 47% protein, 20% fat, 11% ash, and 8.5% moisture. At the end of eight weeks, the relative growth rate and feed intake were significantly higher in fish exposed to 20L/4D than in other photore- gimes. Total protein intake (g), protein retention (%), and N content in fish (%) significantly improved with the increase of light hours, indicating that optimal growth in the study conditions is obtained in extended light regimes (20L/4D or 16L/8D).
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    Effects of Live Food Organisms and Formulated Diets on Growth, Survival, and Body Protein of Asian Sea Bass Fry (Lates calcarifer, Bloch)
    (Israeli Journal of Aquaculture - BAMIGDEH, 2009) Vartak, Vivek Rohidas ; Singh, Kumar
    The effects of the live feeds, Artemia, Moina, and Tubifex, and a formulated diet on the survival, growth, and body composition of fry (0.05±0.001 g) of the Asian sea bass, Lates calcarifer (also called barramundi), were evaluat- ed. The formulated diet was supplemented with dry Bombay duck fishmeal (10%) as an attractant. The experiment was conducted for 30 days in 40-l glass aquaria containing 30 l fresh water. The fry fed Artemia had the best survival (70%) and growth rate (6.48±0.10%). Fry fed Moina and formu- lated diet had 60% survival, not significantly different from fry fed Artemia. Survival was poor (30%) in fry fed Tubifex. Body protein and lipid contents differed significantly among treatments. The present study suggests that Artemia nauplii is the better feed for Asian sea bass fry but formulated diet can be used as a substitute since growth and survival were similar.
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    Embryonic Development of Barbel (Barbus barbus)
    (Israeli Journal of Aquaculture - BAMIGDEH, 2009) Lugowska, Katarzyna
    Barbel (Barbus barbus L.) is rarely bred and reared in hatcheries, and data on the early development of this species are scarce. Thus, the aim of the study was to describe its embryonic development in detail. Eggs and sperm were obtained from artificially stimulated spawning. Fertilized eggs were incubated in ten 2000-ml aquaria filled with aerated dechlorinated tap water and maintained at a constant 18°C, the optimal temperature for embryonic development of barbel. The eggs swelled to a maximum of 18% during the first hour after fertilization. There were eight distinct stages of embryonic development: two blastomeres, eight blastomeres, small-celled blastula, embryo body formation, body segmentation, formation of brain and eye germs, change of yolk sac shape, and first movement of the embryo. Sur- vival during development was over 81% and during hatching 74%. Of the newly hatched larvae, 88% were normal, 7% were dead, and only 5% had morphological abnormalities, the most common of which were yolk sac mal- formations, spinal cord curvatures, and heart edema.
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    Marine Secondary Metabolites (MSM) from Macro Algae Enhance Bacterial Clearance in Hemolymph of Penaeus monodon
    (Israeli Journal of Aquaculture - BAMIGDEH, 2009) Lipton, A.P. ; Pramitha, V.S.
    Marine secondary metabolites (MSM) from macro algae were incorporated into four experimental feeds for juvenile shrimp (Penaeus monodon) as follows: 1.0% Hypnea musciformis extract (diet 1); 0.1% H. musciformis ex- tract (diet 2); 1.0% H. musciformis extract with 500 mg Ulva fasciata extract and 50 mg of the antibiotic levamisole (diet 3); 1.0% H. musciformis with 500 mg U. fasciata per kg body weight (diet 4). Diet 3 enhanced bacterial clearance to 99.69% in the hemolymph of shrimp challenged with Vibrio alginolyticus and Vibrio fischeri, significantly higher than clearance rates in all other treatments and the unmedicated control. Results suggest that feed containing MSM is a good alternative to application of antibiotics in control- ling bacterial diseases in shrimp.
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    Partial Substitution of Fishmeal by Meat and Bone Meal, Soybean Meal, and Squid Concentrate in Feeds for the Prawn, Artemesia longinaris: Effect on Digestive Proteinases
    (Israeli Journal of Aquaculture - BAMIGDEH, 2009) Gimenez, Analia Veronica Fernandez ; Diaz, Ana Cristina ; Velurtas, Susana Maria ; Fenucci, Jorge L.
    The effect of alternative protein sources on proteinase activity in the midgut gland of Artemesia longinaris was studied. Three isoproteic feeds were compared: a basal diet containing 48% fishmeal and 17% soybean meal (diet 1), the basal diet containing meat and bone meal as partial replace- ment of the fishmeal (diet 2), the basal diet containing additional soybean meal and a squid protein concentrate as partial replacement of the fishmeal (diet 3). Midgut gland extracts from the three treatments and wild prawns (control) were assayed to quantify proteinase activity. Specific inhibitors were used to identify proteinase classes by SDS-PAGE. Specific proteolytic activity was highest in the wild prawns and in prawns fed diet 2. Trypsin ac-tivity was higher in prawns fed the diets (1.9-2.6 absorbance/min/mg) than in wild prawns (0.6 absorbance/min/mg). Chymotrypsin activity was high- est in prawns fed diet 2. Proteinase activity in samples on azocasein was inhibited by soybean trypsin inhibitor and Nα-p-tosyl-L-lysine chloromethyl ketone. Electrophoresis revealed at least six different bands with zones having caseinolytic activity in prawns fed the diets as compared to wild prawns, including four trypsins (16.6, 18.2, 21.9, and 25.1 kDa) and one chymotrypsin (53.7 kDa). Our findings indicate that proteolytic activity in A. longinaris adapts to the quality of the dietary protein and that fishmeal can partially be replaced by additional soybean meal in combination with squid protein concentrate.
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    In vitro Antibacterial Activity of Herbal Medicines and Combinations of Herbal Medicines and Antibiotics against Edwardsiella tarda
    (Israeli Journal of Aquaculture - BAMIGDEH, 2009) Bai, D.Q. ; RLi, R. ; Xing, K.Z. ; Guo, Y.J. ; Chen, C.X. ; Qiao, X.T. ; Mao, H.T. ; Zhu, G.X.
    The antibacterial activity of five medicinal herbs, alone and together with other herbs or one of six antibiotics, against Edwardsiella tarda was determined by World Health Organization-International Collaborative Study (WHO-ICS) agar dilution protocol. Minimal inhibitory concentrations (MIC) of the herbs were significantly lower (≤4 mg/ml) in treatments using the combinations Rhizoma coptidis+Radix scutellariae, Galla chinensis+Radix et Rhizoma rhei, Galla chinensis+Radix scutellariae, and Radix et Rhizoma rhei+Radix scutellariae than in treatments using Rhizoma coptidis, Radix et Rhizoma rhei, or Flos lonicerae (≥32 mg/ml). Almost all the combination treatments were more effective than treatment by a single herb. Combinations containing herbal medicines and regular antibiotics resulted in varying results: antibacterial effects increased with some combinations and decreased with others. Galla chinensis is suitable for use with most antibiotics, while streptomycin sulfate is suitable for use with many herbal medicines.