نشریه بهره برداری و پرورش آبزیان
سال پنجم شماره 2 (تابستان 1395)

The increasing demands for food and aquaculture besides the limited natural resources caused the changes of culture systems towards intensive and super-intensive culture in which water is more polluted and probability of developing diseases is higher compared to semi-intensive and open systems. Since application of antibiotics in aquaculture is prohibited under international laws, administration of food additives and immunity complements as a substitute for antibiotics has been studied in the past decade. Application of vaccines is also limited due to host specificity of pathogens as well as the high cost of vaccines. The review of literatures revealed that administration of probiotics, prebiotics, synbiotics, and herbal medicines has been the successful approaches for controlling pathogens. Among those approaches, herbal medicines are cheaper for treatment of aquatic organisms, protect the environment, and have fewer side effects compared to chemicals. This present manuscript reviews the effects of native medicinal plants and their derivate on the immune response of fish and crustaceans.

Probiotic bacteria play an important role in the development of optimal fish culture. This study was carried out to evaluate the effect of Bacillus subtilis probiotic isolated from common carp, on fatty acid composition of fish fillet with an average weight (54/56 ±1 g). Control group fish with common diet and experimental treatments with supplemented diets were fed in two levels of concentration 103 (treatment 1) and 106 (treatment 2) CFU/ ml (cells per ml). The experiment in a completely randomized design with three replications was carried out for 8 weeks. Feed rate was based on 2% of body weight and 2 times at a day. Determination of length and weight were carried out every 14 days. The results of the fatty acid profile showed no significant differences in the amounts of SFA, MUFA, Omega-3, Omega-6 among all with (P>0.05). PUFA and PUFA levels in treatments decreased significantly as compared the control and treatment 2. The
highest amounts of EPA and DHA, were observed in the treatment 1 and the control. The results of this study showed that probiotic bacillus can be affected on fatty acid composition of common carp.

This study was done to evaluate factor cost and profitability of cultured carps production in Golestan province . For data collection, a comprehensive questionnaire was provided including information from farms (fixed and variable costs) and farm's managers. 30farms were randomly selected. The collected information was analyzed using SPSS program. Result showed that with the average larvae stocking density of 1955 per hectares and produced carp of 2533 kg/ha, the average cost of fertilizer, food, energy, manpower, larvae and bank interest was calculated 4352/4, 2538/9, 2357/56, 1994/85, 1623/157 and 1269/45 respectively. The average profit, benefit-cost and rate of return of investment were 29000 Rials per kg, 6/2 and 50% respectively.

With increasing world population, food production industries such as aquaculture needs to be expanded very well. An innovative technology which is called biofloc technology (BFT) can follow the objectives of sustainable aquaculture by using zero-water exchange system. BFT is the eco-friendly aquaculture system that considered as an efficient alternative system since nutrients could be continuously recycled and reused as food for aquatic. This technology is basically dependent on adjustment of carbon/ nitrogen (C/N) ratio for development of microbial community and bioflocs which leads to microbes harvest excreted inorganic nitrogen and produce microbial proteins. These bioflocs improve water quality. Limited water exchange, minimizing the effluent, maintaining of water quality, food supply, reducing protein in food, growth improvement, biosecurity and production of organic products are the important of this technology that has greatly considered during these past two decades. In this review, introduction of biofloc technology will be discussed, that can be suggested as a strategy for enhancement and development of sustainable aquaculture in country and also as an appropriate way for beneficial use of water resources.

The development of large complexes aquaculture, including shrimp culture increases the risk of environmental pollution. The outgoing effluent control to reduce the pollution load is considered one of the vital. This research was conducted on shrimp farms in the northern of Gomishan city in Golestan province. For this project, the 2 stations, at water input and output lagoon, in the last 3 months during the breeding period (end of August, September and October in year 1394) by measuring some the physicochemical parameters including temperature, pH, EC, BOD, TSS, NO3, PO4 and NH4 samples were taken. Then Statistical analyses of experimental data were analyzed with SPSS 17 software and mean comparisons were assessed at 5% confidence level. According to the results of this study, it was observed that the values of pH, temperature, total suspended solids, BOD, nitrate, ammonium and phosphate ions at three points, entry site, which indicates a lack of impact of shrimp farming on these factors. The results showed that shrimp farms significantly increased the electrical conductivity and total dissolved solids in the water output compare with the site input. In general, due to the factors, Gomishan shrimp farming with this volume of production, is not a serious threat for Gomishan wetland and the Caspian Sea ecosystem, But if the area of shrimp rearing grows and the next phase start to work should be thought of solutions for wastewater treatment because it increases the likelihood of contamination of wetland so can create the serious risks for the environment.

Calcium is involved in the formation of the shell of bivalves. The shell is produced by the mantle. Despite the undeniable importance of mantle and calcium in the formation of the shell, in Iran no studies have clarified the structure of the mantle edge and detection of calcium in it. The present aimed to provide a detailed description of the structure of the mantle edge and identify the presence of calcium in the important species of Persian Gulf, Chlamys ruschenbergerii. The anterior and posterior segments and the center segment of the mantle edge of each valve were cut, and the tissue sections were stained with Harris Hematoxylin and Eosin. Alizarin red S and Von Kossa methods were used to detect calcium content in the mantle. The result showed that the mantle edge of Chlamys ruschenbergerii consists of outer, middle and inner fold. Each of the three folds has a different shape and size. It was observed the differences in the structure, height and the kind of epithelium in various area of the mantle edge. Calcium was not detected in the mantle of Chlamys ruschenbergerii.

The effect of diet containing astaxanthin on continuous quality fish rainbow trout for 8 weeks with synthetic astaxanthin concentrations of 100,60,40 mg per kg (mg / kg) were used for food. Trends and compare the quality of the samples, using chemical indicators, as well as color index L * a * b *)), in five separate time periods every 4 days (16,12,8,4,0) in typical refrigerator temperature were taken. The results showed that the highest levels of astaxanthin (100 mg) in the diet of rainbow trout compared with the amounts (40 mg) (60 mg) resulted in improved Meat quality status in terms of reducing the amount of PH, PV TBA and FFA in maximum storage time was due to the antioxidant properties of these compounds As the antioxidant and control groups were statistically significant (0/05> P) also can be colored based on the highest levels of astaxanthin for use in feed for the fish offered.