نشریه بهره برداری و پرورش آبزیان
سال چهارم شماره 2 (تابستان 1394)

This study compared the effects of different levels of dietary fat on growth performance, liver enzymes and blood biochemical of juvenile Siberian sturgeon (Acipenser Bearii) was designed for 12 weeks. For this reason 135 fish (15.6 ± 0.33g; mean ± SD) at nine 500 liter fiberglass tanks, each one containing 15 fish. Three experimental diets with the same protein (42 %) and 3 fat levels 10, 15 and 20 percent (as low, optimum and high level) was formulated. During the breeding period, fish fed manually three times a day to the extent of satiety. At the end of the growth period, the results indicated that the fish fed with diets containing 15% fat, had significantly higher weight gain (WG) and specific growth rate (SGR) in comparison with fish fed with a 20% fat treatments (P

The correlation between serum steroid hormones, testosterone (T), 17β-estradiol (E2), and progesterone (P) and weight of female fishes, biological characteristics of gonad (e.g. fertilization rate, fluid egg rate, gonadosomatic index , polarization index and oocyte diameter) in 10 female of the migratory population of Sterlet (Acipenser ruthenus) and 5 female of the migratory population of Siberian sturgeon (Acipenser baeri) in Spring of the 2012 were determined. In Sterlet, significant negative correlations were observed between 17-β estradiol and polarization index (P

The present study was designed to evaluate blood factors in the Flower horn fishes that were fed with different levels of hydrolyzed cow skin. 216 fishes with average weight and length, respectively, 0.95 ± 0.2 (g) and 3.7 ± 0.2 (cm) During the 100-days period of experiment were fed. Results showed that in the treatments fed diets containing 40% hydrolyzed cow skin, number of RBC with mean (2.5 ± 0.33) ×106 , percent of Htc (25 ±1.72) and hemoglobin (8.5 ±1.66) grams per deciliter, was increased compared to controls (p0.05). The highest values of MCV factor with average (1.04 ±0.32) was related to treatment %100 (p

The sterlet (Acipenser ruthenus) is one of the species of the exotic sturgeon (Acipenseridae) family in Iran. This important species produces caviar every year at the lowest cost and in the shortest time. The objective of this research was to assess the effect of Digestarom, as a nutritional supplement, on the growth indices and safety factors of synthetically-cultured baby sterlets (Acipenser ruthenus). This research was conducted in autumn 2013 on synthetically-cultured baby sterlets in a fisheries laboratory of the Islamic Azad University of Rasht. The research plan was designed randomly with three treatment groups and one control group. The supplement under study was added to the basic diet of the samples in the following three dosages: 1, 1.5, and 2 gr/kg. A total of 72 juvenile sterlets with an average weight of 88.60 1.35 were divided into 6-member groups and were put in twelve 100-liter tubs. The samples were fed for 60 days manually based on 3% of their body weight. At the end of the aquiculture period, the study of some of the growth parameters of the samples revealed that the 1.5 gr dosing of Digestarom (as a nutritional supplement) had a considerable effect and the results obtained from this dosing were significant different than the results of the control group. However, in the examination of safety factors it was found that the total immunoglobulin level, lysozyme (2 and 1.5 gr), and IgM only increased considerably with 2-gr dosing of the supplement as compared to the control group samples. Therefore, research results indicated that the growth and safety parameters were satisfactory with the 1.5 and 2 gr/kg dosages of the aforementioned nutritional supplement.

Whit the extension of nanotechnology and materials engeneering, various nanoparticles are produced that have new characteristics but the toxic effects of them is still unknown in most of materials. Nowadays metal oxide nanoparticales are widely used in indusery and other fields. This study was conducted goldfish with the average weigh of 3±0.5 gr and owerag length of 7±0.5 cm nd four cares of zinc nanooxide (0, 5, 20, 50 mg/lit) was done on them repeated for three times for 14 days. The sampling on the fish of each repeat was done on days 1, 3, 7 and 14. The results of gill analysis showed mucos, loss secendary lamella, la,ellar fusion, Epithelial lifting, Hyperplasi, aneurism and degeneration of secondary lamella. The overall result of this study showed that increasing the amount of nano-zinc oxide and duration of exposure also increases the amount of damage.

Sturgeons in the Caspian Sea due to its unique characteristics in terms of economic and social in Caspian countries have a high economic value at the national and even international levels. Persian sturgeon (Acipenser persicus) is considered one of the most valuable Caspian Sea fishes in terms of restocking, caviar and meat production. Nowadays, the possibility of Persian sturgeon Proliferation is gone due to various possible reasons. One of the most effective methods of artificial reproduction is using the LHRH-A hormone plant. In this review, this study aimed to investigate the proliferation of immature Persian sturgeon using LHRH-A hormone plant was done by Research Center of freshwater fish stocks, Shahid Marjani fish Reproduction and breeding center, in 2008. In this study there was three treatments; T1: 10 µg/kg body weight, T2: 15 µg/kg body weight, T3: 20 µg/kg body weight and a control group: T4: 0 µg/kg body weight. Artificial propagation was done in accordance with the present method in sturgeon Reproduction and breeding center. This study was performed based on a randomized complete block design with three replicates for each treatment. One-way ANOVA was used for fertilization and hatching rates by using SPSS software. Duncan and Dunnett 3 tests were used for comparison of different treatments. The results showed that there was a significant difference between the percentage of fertilization and hatching rate of control and T2, T3. Fertilization increased as hormone does increased to 15 µg/kg body weight but it decreased from 15 to 20 µg/kg body weight but this reduction was not significant. Also there was a positive linear correlation between hatchability and hormone increase to 15 µg/kg. In conclusion, we can state unequivocally that the plant hormone, LHRH-A to the value used in this project has positive effects on Persian sturgeon sexual improving.

This study Investigated of antibacterial and antioxidant activity of garlic and lemon extract (1.5 %) on the quality and shelf life of fillet, vacuum-packaged Rainbow trout (Oncorhynchus mykiss) during refrigerated storage. were studied by monitoring the microbiological (totalviable count, psycrotrophic), chemical (TBA), pH and sensory changes for a Period of 20 days in (0, 5, 10, 15 and 20). Effect of garlic and lemon extract significantly (p≤0/05) delayed lipid oxidation, psycrotrophic bacteria and total viable count of treated samples. According to sensory and microbial analysis garlic and lemon samples in compare with the control samples were acceptable for eat to end of storage.

By-product of fisheries processing plants applicable protein. In this study effect of papain (plant origin), Trypsin, Pepsin (animal), Alkalaz, Prvtamks, Flavrzaym (microbial), and temperatures of 30, 60, 90, 120, 150, and 180 minutes on the hydrolysis of rainbow trout waste were examined. The recovered peptone in the media as a source of bacteria Lactobacillus plantarum and Aeromonas hydrophila was evaluated in the present study. Effects of enzyme and time and their interactions on degree of hydrolysis and peptone yield was significantly different. The protein content and degree of protein hydrolysis increased by 90 minute and then decreased from 90 to 120 minute, and henceforth was almost constant by 180 minute. The results showed that the protein content and the degree of protein hydrolysis using Alkalaz was better than the other enzymes. Bacteria showed better growth rate in media containing peptone as compared with TSB and MRS as commercial media (control).

Rivers and streams are one of the most important water resources. Rivers water quality depends on various conditions such as hydrological, physicochemical and biological processes.Water resources have significant impact on social, economical and political developments. The Zyarat Watershed which is the main source of surface water to supply water for city of Gorgan and surrounding areas has been confronted with potable water quality deterioration problem in the recent years, therefore its management and water quality control has specific importance .In order to, Samples were taken from 10 hydrometery stations (in Spring and Summer 2012) along the Zyarat Stream. At each sampling DO, pH, BOD5, NH3, NO3, PO4, TS, Water temperature, turbidity and Fecalcoli quality was measured. The data were analyzed by NSFWQI quality index. The result showed that the best situation was related to first station in Khordad month and the worst situation was related to 5 station in Ordibehesht month. As for present results quality condition of Zyarat Straem was unsuitable and the decision making process for reducing the pollutant of the Zyarat watershed can be facilitated by taking into consideration the results of this research given the time/budget constraints.