IJA Volume 55, Issue 1, 2003

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    Ammonia Nitrogen Excretion Rate - An Index For Evaluating Protein Quality Of Three Feed Fishes For The Black Sea Turbot
    (Israeli Journal of Aquaculture - BAMIGDEH, 2003) Yigit, Murat ; Koshio, Shunsuke ; Aral, Orhan ; Karaali, Burcu ; Karayücel, Sedat
    Total ammonia nitrogen excretion rates were measured in young Black Sea turbot (74.79 g avg wt) reared in brackish water (17 ppt salinity) at 11±0.3°C. Duplicate groups of turbot were fed a fixed quantity of teleosts, either anchovy (Engraulis encrasicolus), goby (Gobius sp.) or whiting (Merlangius merlangus). Feeds were offered to the turbot as wet feed. Cumulative ammonia-N excretion over a 6-hour period was significantly lower (p<0.05) in fish fed goby (3.64±0.27 mg- N/100 g fish) and whiting (3.83±0.13 mg-N/100 g fish) than that in fish fed anchovy (4.48±0.06 mg-N/100 g fish). The ammonia-N excretion rate in all groups peaked two hours after feeding, but the peak value in the group fed anchovy was significantly higher (p<0.05) than in the other two groups. No differences were observed among diets in samples taken 3, 4, 5 and 6 hours after feeding. Significantly lower excretion levels in the goby and whiting groups could be relat- ed to the protein quality of these species which may be higher than that of the anchovy for tur- bot nutrition.
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    Growth, Feed Utilization And Carcass Composition In Rainbow Trout Fed Diets With A Similar Digestible Energy Content And Different Carbohydrate Levels
    (Israeli Journal of Aquaculture - BAMIGDEH, 2003) Tekinay, Ahmet Adem ; Davies, Simon John ; Güner, Yusuf
    Three diets including 13.2%, 22% or 30.5% carbohydrates as extruded wheat meal were fed to rainbow trout, Oncorhynchus mykiss (initial weight 34.8 g), for twelve weeks to investigate their influence on growth, protein and energy utilization and carcass composition. Daily feeding rates were 1.76, 2.05 or 2.17 g feed per 100 g body weight for the three diets, respectively, so as to reach a daily allowance of about 35.5 kJ digestible energy per 100 g body weight. No significant differences (p>0.05) in final mean weight or specific growth rate were observed between the treatments. Feed efficiency was negatively correlated to the dietary carbohydrate level. Utilized digestible protein and energy per kg growth were 365, 348, 358 g and 15.4, 15.9, 17.0 MJ, respectively, for the three diets. Apparent net protein and energy utilization of the groups fed a medium or high carbohydrate level were higher than those of the low carbohydrate group. Analysis of fish carcasses at the end of the trial revealed no significant (p>0.05) variations attrib- utable to the carbohydrate level.
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    Natural Spawning And Rearing Of Mangrove Red Snapper, Lutjanus Agentimaculatus, Larvae In Captivity
    (Israeli Journal of Aquaculture - BAMIGDEH, 2003) Leu, Ming-Yih ; Chen, I-Hui ; Fang, Lee-Shing
    Mangrove red snapper (Lutjanus argentimaculatus, Forsskål) spawned naturally in captivity, without the use of hormones or other treatments, from May 21 to September 15, 1999. Each female laid an average 2,350,000 eggs. Larvae were reared in 4-ton circular fiberglass tanks. They were first fed S-type rotifers (Brachionus rotundiformis). Later, Artemia nauplii and cope- pods were added to the diet. They were weaned onto an artificial diet. Metamorphosis began at 18 days when the larvae reached 10.5 mm total length and was complete by day 30 when lar- vae were 17.2 mm. From day 26, large larvae (over 25 mm) cannibalized their smaller siblings. Abnormalities were observed in 4.9% of the individuals. At 50 days, the larvae rearing trial pro- duced juveniles of 49 mm average total length with a survival of 10.8-32.3%.
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    Effect Of Animal And Plant Protein Diets On Growth And Fecundity In Ornamental Fish, Betta Splendens (Regan)
    (Israeli Journal of Aquaculture - BAMIGDEH, 2003) James, Raja ; Sampath, Kunchitham
    The effects of different levels of animal and plant protein (10%, 15%, 25%, 35% and 45%) on growth and fecundity in Siamese fighting fish, Betta splendens, were tested over a period of 154 days. Fish fed 35% animal or plant protein had the highest mean body wet weight, growth rate, gonad weight and fecundity than any other tested level. Animal protein induced gonad develop- ment earlier than plant protein. Female B. splendens fed the 35% animal protein diet had a 79% higher gonad weight (87 mg wet weight) than those fed the diet with the same level of plant pro- tein (49 mg wet weight). Spawning trials showed that 35% animal or plant protein diets produced the highest number of eggs and the highest hatching rate compared to the other diets; hence, 35% animal or plant protein is considered the optimum level for B. splendens. Females fed the 35% animal protein diet laid 1044 eggs in three spawnings in contrast to 846 eggs produced by fish fed the 35% plant protein diet. The necessity of incorporating an optimum level of animal protein in the diet for maximum reproductive performance in B. splendens is discussed.
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    Prediction Of Carcass Quality Traits Of Common Carp By X-Ray Computerized Tomography
    (Israeli Journal of Aquaculture - BAMIGDEH, 2003) Hancz, C. ; Romvári, R. ; Petrási, Z. ; Horn, P.
    X-ray computerized tomography (CT) and chemical analysis were used to determine the fat and protein contents in the fillet of table-sized mirror carps. Serial CT scans were taken along the body from the operculum to the beginning of the caudal fin. After scanning, the anesthetized fish were immediately processed; slaughter value and fillet yield were determined before taking sam- ples for chemical analysis. Independent variables of prediction equations were produced from the CT density values, which ranged from -90 to 160 on the Hounsfield scale. Based on the data derived from the CT scanning, areas (cm2) of muscle and fat tissue were identified. Fat deposi- tion was highest in the dorsal fin region. The muscle area varied according to the body shape and seems to be inadequate for predicting the slaughter value of common carp. The fat and pro- tein contents of the fillet, when predicted from scanning only the dorsal region, were as accurate as when predicted from scanning the whole body and were R2 = 0.88 and 0.86, respectively.
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    Supplementation Of An Isolated Fish Gut Bacterium, Bacillus Circulans, In Formulated Diets For Rohu, Labeo Rohita, Fingerlings
    (Israeli Journal of Aquaculture - BAMIGDEH, 2003) Ghosh, Koushik ; Sen, Sukanta Kumar ; Ray, Arun Kumar
    An extracellular protease producing bacteria Bacillus circulans (Lr 1.1) was isolated from the gut of rohu, Labeo rohita, fingerlings, and used as a supplement in five diets for rohu fingerlings. The effect of the supplement on the growth performance and feed utilization efficiency of the rohu was evaluated. Rohu fingerlings (avg wt 0.83±0.02 g) were fed diets supplemented with 1.5 x 104 (diet D2), 1.5 x 105 (diet D3), 1.5 x 106 (diet D4), 1.5 x 107 (diet D5) or 1.5 x 108 (diet D6) B. circulans cells per 100 g feed for 60 days at 3% of the body weight in triplicate treatments. The control diet (diet D1) was not supplemented with the bacteria. Diet D3 resulted in signifi- cantly better growth, a lower feed conversion ratio and a higher protein efficiency ratio than the other experimental diets. Intestinal α-amylase activity did not differ significantly beyond the low- est inclusion level (diet D2), whereas protease activity increased significantly with diets D2 and D3. Apparent dry matter and protein digestibility did not significantly correlate. However, lipid digestibility decreased with the increasing level of B. circulans.
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    Growth And Yield Of Asian Catfish Clarias Macrocephalus (Gunther) Fed Different Growth-Out Diets
    (Israeli Journal of Aquaculture - BAMIGDEH, 2003) Coniza, Eliseo B. ; Catacutan, Mae R. ; Tan-Fermin, Josefa D.
    Juveniles of the Asian catfish Clarias macrocephalus (3.6±0.17 g; 78.0±0.09 mm) were fed one of four diets: a laboratory-formulated diet of 18.9% (Diet 1) or 34.2% (Diet 2) protein, a com- mercial feed pellet of 28.9% protein (Diet 3) or a diet of 80% blanched chicken entrails and 20% rice bran (31.7% protein; Diet 4). After 120 days of culture, catfish fed Diet 2 grew significantly better (p<0.05) than the other groups, reaching 108.9 g and 232.8 mm (daily weight gain 0.88 g; specific growth rate 2.9%), with a condition factor of 0.86 and production of 18.2 kg per 25 m2 pen. Feed conversion with Diets 2 and 3 (2.5 and 2.3, respectively) was better than with Diets 1 and 4 (3.4 and 5.0). Survival (68-81%) did not differ significantly among treatments (p>0.05). Catfish fed Diet 2 had the highest apparent lipid retention (131.7%). The protein efficiency ratio was lowest (1.3) in Diet 2, but did not differ significantly from Diets 1 and 3. Catfish fed Diet 4 were fatty and had a lower crude protein content. Results suggest that C. macrocephalus fed 34.2% crude protein have a significantly higher weight and total yield. Further, a taste test showed that odor, flavor and appearance did not differ amongst the diets.
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    Epidemilogical Description Of A New Viral Disease Afflicting Cultured Cyprinus Carpio In Israel
    (Israeli Journal of Aquaculture - BAMIGDEH, 2003) Perelberg, Ayana ; Smirnov, Margarita ; Hutoran, Marina ; Diamant, Ariel ; Bejerano, Yitzhak ; Kotler, Moshe
    Since spring 1998, a new disease causing high mortality has afflicted cultured ornamental and common carps (Cyprinus carpio) in Israel. The clinical signs of the disease are fatigue, gasping movements in shallow water, gill necrosis, sunken eyes, pale patches on the skin and increased mucus secretion. The disease was experimentally transmitted to koi and common carp of vari- ous ages by injection with affected tissue filtrates, cohabitation trials and exposure to the isolat- edviralagent.Immersionofhealthyfishintankscontaining2.7x104 plaqueformingunits(PFU) per l or intraperitoneal injection (0.2 ml) of a viral inoculum of 1000 PFU/ml were sufficient to induce the terminal disease in over 80% of the fish. Here we report that the disease is restrict- ed to C. carpio, that young fish of 2.5 g and 6 g are more sensitive to the virus than adults (230 g) and that the virus remains active in the water for at least four hours.