نشریه علوم آبزی پروری پیشرفته
سال یکم شماره 3 (زمستان 1396)

A feeding trial was conducted to examine the effects of dietary supplementation of betaine (0.5, 1, 1.5, 2 & 2.5 % Betaine kg-1 diet) on growth, nutrient utilization, carcass compositions and haematological- biochemical parameters in beluga, Huso huso. 300 fish with average weight of 4.6 ± 0.61 g were fed to triplicate groups of experimental diets for 12wk. Significant higher weight gain, specific growth rate, protein efficiency ratio, condition factor and feed efficiency ratio were observed in fish fed diet supplemented with optimum levels of Betaine than that of fish of control dietary group. The best growth performance and nutrient utilization was observed in fish fed diets containing 1.5 -2 % Betaine kg-1 diet (p<0.05). liver enzymes (Alanine aminotransferase and Aspartate aminotransferase) in fish fed diet containing 1.5 and 2 % Betaine kg-1 diet were significantly higher than those of fish fed basal diet. Based on the results of this study, could say that increased levels of Betaine in the diets of juvenile beluga up to 1.5-2 % kg-1 diet, improved growth performance, feed utilization and haematological- biochemical parameters.

This study was conducted in 2015 to identifying problem and limitations of sustainable development of warm‐water fish farming in Rasht. The method of descriptive research was survey research. The Statistical population of fish farmers was 1022 around the Rasht and Sangar basin. The samples were determined by using of Bartlett minimum sample size table (n=175) Which were conducted with random sampling. The comments of fisheries scientist were gathered by questionnaire forms. For looking for research tool's steady state,20 questionnaire forms were completed out of the samples, and the Coronbach's alpha coefficient were obtained ( 0.86).The problems were categorized by for section  of Economic, Social, management and  Education-promotion. The most important of economic problems of Warm water fish farming were high bank profits, the high cost of ingredient for aquaculture (food, fertilizer, fingerling, fuel, energy, high water charges ,…) which ranked first to third ,respectively. The low consumption per capita of farmed fish and poor operation of warm water fish farming union were the most important social problems. The lack of farmed fish expert, lack of communication between research centers and fish farms and low rate of production per unit area were the most important management and policy issue . The insufficient training courses, unavailability of the internet and scientific journal for fish farmers and low education levels of fish farmers were the most important technical problems of education and promoting. In this study revision protectionist policy, removing barriers of production, practical training course to improve the technical skills of fish farmers, low-interest loans, to solve problems related to the high cost of factors, promoting of fish consumption and to create necessary infrastructures for processing and storage of fish were proposed

In the last years, an invasive species, the oriental river prawn (Macrobrachium nipponense), has adapted in Anzali wetland (Iran), and it is a treated for this wetland. Current study demonstrated the preventive strategy for capture of the M. nipponense shrimp as a valuable nutrition and fatty acids components. Samplings were done with electroshock instrument seasonally at three habitats of Anzali wetland. Results showed that there was not significant different between total fatty acids and MUFA fatty acids at three habitats (p<0.05). But there was significant different between C20:4n6, C20:5n3 and C22:4n6. The range of AI and TI indexes was between 1.4 to 2.02 and 0.42 to 0.50 respectively at three habitats. The amounts of current data, n-3/n-6 and EPA/DHA ratios were lower than the maximum amount of reported data by U.K health department. So we can suggest that this species is as a health food for human.According to the preventive strategy for control of M. nipponense population, the fishery of this species is useful as a nutritional food, economic and rural development.

This project implemented in Aquaculture institute to goal of brood stock making bio-normative determination of crayfish (Astacus leptodactylus) in captivity condition in 2007-2009. For this purpose, 500 wild brooders caught from Aras Dam Lake and handled to Sefidroud Fisheries Research Station. After hatching of eggs, juveniles of crayfish reared in two earthen ponds. The juveniles reached to more than 15 g weight in the end of first year. Then young crayfish in three treatments inclusive 3, 5 and 7 animals per m2  with 1:1 sex ratio introduced to 9 ponds 150 m3 and fed with especial diet (35 % protein,  13 % fat and 4000 kcal/kg energy). Every treatment had 3 replicates. In period of rearing conducted biometry, physical-chemical factors measurement and gonadal histology. The end of second year, more than 50 percent of crayfish reached to maturation stage. The results showed that mean survival of animals was 86.87 and 90.44 percent in the end of second and third rearing year, respectively. The highest and lowest brooders number with pelepod eggs resulted in first treatment (58.91 percent) and third treatment (53.47 percent), respectively. Maximum juvenile crayfish produced in third treatment with 18.5 percent. Also, eggs and pelepod juveniles produced 58.73 and 15.56 percent in first and 54.35 and 14.52 percent in second year, respectively. Finally, average size of crayfish measured 90.48 g in weight as maximum and  minimum size was 206 and 48 g. Mean length of animals was 13.7 cm the end of the trial.

Sturgeon fishes are the most important species in the world base on caviar production and biodiversity. In order to promoting quantity and quality production of Acipenser persicus larvae in proliferation and propagation centers of sturgeon fishes and to survey possibility release larvae to the Caspian Sea directly at stock enhancement procedure, artemia naupli as live food enriched with an commercial emulsion ICES30/4 and ovarian sturgeon oil accomplish with 10, 20 and 30 percent of vitamin C during 12 and 24 h enrichment period and fed to sturgeon larvae for 20 days. Results showed the best quantity and quality 700 mg WW larvae  were obtain when they fed with ICES30/4, 20 % vitamin C during 24h enrichment and this treatment implemented the best survival rate when they exposed to salinity stress 120 ppt during 120 h.

Phytobiotics are plant derivatives derived from leaves, roots, tubers or fruit plants, solid, dry or essential oils to improve nutrition for livestock and poultry farming. These plant derivatives are well-practiced in aquaculture, such as: stimulating food intake, increasing growth, increasing digestive tract discharges, increasing immunity, anti-coccidiosis and parasitic activity. Existing materials are from bioactive chemical groups such as alkaloids, phenols, flavonoids, terpenes and polysaccharides. Various methods are used to extract these effective ingredients. The choice of these methods in terms of plant species, solvent type, use or non-use of heat requires different techniques. In this paper, while reviewing the use of phytobiotics in aquaculture, the introduction of classical and modern techniques in this regard has been considered. Reports indicate that methods Modern due to the reduction of organic and synthetic chemicals and, saving time, efficiency and better quality of the extractive material are of interest to researchers. And given the need to take advantage of these valuable biomass in aquaculture, familiarity with these techniques in the future will be the key to achieving sustainable aquaculture.

Majority of rearing costs are created by food and this topic indicated the importance of feeding management in aquaculture. The aim of the present study was to review the feed deprivation and feed restriction on growth performance and physiologic fuels of sturgeons. Reorganization of metabolic operation is an important strategy to consume energy reserves when food availability is limited. Decreasing in metabolic rate resulted in body mass reduced that is common response to feed deprivation and feed restriction periods. Liver plays an important role compared to viscera and muscles for supplying energy in maintaining basic metabolism. Body reserves of sturgeons mobilized glycogen, lipid and protein, respectively for providing energy. Liver glycogen constitutes first energy reserves in sturgeons and this way supplied the requirement glucose for tissues and cells. As respects glucose have a vital role in body, plasma glucose level controlled by glycogenolysis and gluconeogenesis of non-carbohydrate precursor. Energy reserves levels were fluctuated with species physiology, size, intensity and duration of feed deprivation and feed restriction. Long history of sturgeons led to more resistance against unfavorable conditions and these indicated metabolic adjustment ability during short or long-term starvation. It is required to determine appropriate feeding schedule according to species, fish status, water temperature and rearing condition due to prolonged rearing period, high costs of food and final maturation of sturgeon particular at winter season. The purpose of these strategies are to accesses maximize growth without negative impacts on physiological performance of sturgeons, economizes food costs and helps to improve water quality in controlled conditions.

Hygienic care is essential to regarding the development of activity of rainbow trout reproduction centers in our country and in order to achieve more production . Therefore, hygiene management can be considered as the main pillar of rainbow trout economic production. So it is necessary that considerations of health and prevention policies to be implemented very carefully. Egg disinfection to achieve survival rates in trout hatchery is one of the most important pillars of hygiene management. During egg incubation in order to minimize of Fungal, bacteria, parasites and viruses contamination are widely disinfected by various types of disinfectants. Considering the growing importance of this industry in our country and the need to understand the types of used disinfectants , This article describes the common types of chemical disinfectants in rainbow trout hatchery and makes it easy for the former to use the best disinfectant material in the reproduction center, according to the conditions.

Fish protein concentrate production of silver carp meat was obtained by drying (60 ° C) in three steps using solvent(Isopropyl alcohol) and the concentrate have 93% protein, which according to aquatic protein sources have a high nutritional value and are used to enrich other food products. The present study, given that the current noodle production is from the source of carbohydrates and is lacking in terms of lysine and threonine amino acids, this gives the opportunity to be used to enrich and enhance its nutritional quality. In this research, 5-15% of fish protein concentrate ratios were used for enriched nodal, and samples were prepared in 3 replicates and stored at ambient temperature for 3 months and matured sensory evaluation were performed and compared with control (without) concentrate. Finally, statistical analysis of data using Spss version 17 was used to compare the data of the treatments with Duncan test. According to the results of sensory tests, after the statistical tests, the data were determined. In terms of taste and shelf-life of the treatment, Created with 5% protein concentrate, is better evaluated than other treatments, in the first assessment, in the overall assessment of fish protein concentrate enriched treatment with 5% better than other samples, there was a significant difference (P<0.05)

European catfish Silurus glanis L.,1758, belonging to family Siluridae andorder Siluriformes, which are found in water bodies of north of Iran and one of their distribution points is Anzali lagoon. Totally 196 specimens from Oct. to Sep. were study for age, body size, Testis weight, liver weight in Anzali lagoon. In this study reproduction cycle, type, season and optimum temperature of spawning period was studied by Gonado-Somatic Index (GSI), Hepato-Somatic Index (HSI)and Condition Factor (CF). The maximum mean of Gonado-Somatic Index (GSI) reach to 7.82 ± 3.04 (%) in May and June, then GSI value started to decrease from July to September in the end of spawning period. From second stages of maturation GSI Value significantly increased and showed maximum amount in the 5th stages of maturity, then decreased in the 6th stages. Result of this study shows that development of sexual maturity of testis reached maximum values in April and May and in this period water temperature was 19.33 - 22.73 ºС. Variations in GSI values show that reproduction has annual cycle which begins in September and ends in June of next year. The rate of HSI had fluctuation, during the study period .The maximum value (1.95±0.22%) of it’s was in November and the minimum HSI (0.79 ± 0.12%) in July. The Condition Factor also changed during reproduction cycle and it was maximum in September (0.7±0.18%) and minimum in June. Concerning these investigation Silurus glanis is has a Prolonged Reproduction period extending from the April to half of June.