نشریه علوم آبزی پروری پیشرفته
سال سوم شماره 3 (پاییز و زمستان 1398)

By increasing the world population, agriculture development as a trustee of human food suppliers has more importance, so the extension plays a serious role as the link between research and the field. Aquaculture is the knowledge-, technology- and skill-demanding business that requires extension services for capacity development of human resources. The producers’ training in increasing raw products productivity and marketing are some of the key roles in promoting fishery products. Preparing paste and smoked products, different kinds of fillet and packaging which help in maintaining the quality and easy to use of fish are some of the main processing methods for improving fishery product marketing. This study aims to introduce silver carp’ value-added product including high-quality fillet, smoked fillet, fish ball, and fish burger in Ahvaz city, and then assessing the people’s feedback to these products. The results of completed questionnaires indicated that more than 70% and 50% of responders were satisfied of pastry product (fish ball and fish burger) and silver carp hot smoked fillet, respectively. Moreover, the most satisfaction (60%) among raw products belonged to silver carp minced toward fillets. The results of this study anticipate the bright future for the processing industry in Khuzestan province. Also, the importance of extension is highlighted in the opening up of products to different classes of people.

This study was carried out in 27 study stations in Shijan, Siakishim, Abkenar, Hendekhaleh and Rogaha(River outlets), during conducting research hydrology and hydrobiology and preparing Atlas of plankton in the Anzali wetland during the years (1376)1997 from (1393)2014. Sampling was done by (P.V.C) tube, The samples were fixed with 4% formalin and then transferred to the laboratory and after quantitative and qualitative studies with inverted microscope were taken picture them by Nikon Labophot microscop. For phytoplankton (1 liter of water sampels) were Collected alive with (p.v.c) tube (lenth , 2 m) and transfer to laboratory. samples were analyzed under a invert Microscope and then separate with Pasteur pipette and photography from different side by Nikon Labophot microscop. In total, 39 genus and 87 species were identified in the Bacillariophyta. This phylum includes a Class called Bacillariophyceae and 2 important order called Centrales and Penales, commonly referred to as "Golden- Brown Algae". The most abundant Genus of Bacillariophyta are Synedra ulna, Cyclotella meneghiniana, Navicula cuspidata, Diatoma vulgare, and Nitzchia acicularis. The members of this category are mostly Psychrophilic in autumn and winter, it is dominated by a large variety, but in warm and temperate seasons, especially in the most of the Anzali wetlands are located in the siakishem and mainoutlets, but most of their distribution are in the Abkenar area.

Feeding Frequency can affect various commercially important features such as increased biomass, growth and decreased ratio of foods, increased body weight, increased relative size, and improved tissue composition. Experiments were carried out in 100-liter fiberglass tanks containing 25 grams of 1.2 gram Rutilus kutum with a density of 0.5 g / L. The fish were divided into four treatments including 1, 2, 3, and 4 of Feeding Frequency. Each treatment was repeated 3 times. According to the Tukey test, there was a significant statistical difference between 2 treatment with 3 and 4 treatments, and also treatment 1 Feeding Frequency (P<0.05), considering food conversion rate (FCR), special growth rate (SGR), and weight gain (WG). The results showed that the maximum and minimum amount of weight gain has occurred in treatment3 (mean= 99.09±10.93) .and 1 (mean= 47.12±10.53), respectively. The minimum of the special growth rate (0.64±0.12) was observed treatment 1 and the maximum of that (1.15±0.09) was measured in treatment3. The minimum average of FCR (2.42±0.23) was referred to as treatment3 and the maximum of that (4.76 ±1.03) was referred to as thetreatment1 Feeding Frequency. Overall results showed that feeding three a day, the most appropriate method for growth Rutilus kutum,Fingerling

Eurasian perch (Perca fluviatilis) is one of the endemic species of Iran which has wide global distribution and its wild populations are found in northern Iran, Caspian Sea basin. This species has high nutritional and commercial values, but unfortunately, harvesting pressure and habitats destructions led to drastic decline of its natural stocks in recent years. Already, restocking of this fish has received less attention. One of the main barriers on this way is lack of sufficient information in different aspects of biology and supply of Eurasian perch seed. According to high importance of in-captured propagation and also larviculture biotechniques for success in stock rehabilitation and aquaculture of Eurasian perch, the current study follows the aim of review on methods for propagation and rearing of this valuable species.

Pike (Esox lucius) is a native species in Anzali wetland and because of its flesh it has been interested to people for a long time. This study was done to compare the rate of accumulation and concentration of pollutants, heavy metals such as lead and chromium in edible muscle tissue of pike at three stations (West, Central, and East) of Anzali wetland. In this study, fishes were randomly caught in the number of 10 from each station in standard weights by gill nets. After removal of the tissue samples, for chemical digestion true mixed acid digestion (HNO3 / HCLO4) was performed on samples. Heavy metal concentrations were measured using flame atomic absorption spectrophotometer. The results showed that the average concentration of lead metal in the Catfish were 0.52, 0.45 and 0.49 μg/g dry weight and the average concentration of chromium metal in the Catfish 0.08, 0.14 and 0.09 μg/g dry weight were observed for West, Center and East of Wetland, respectively. In this study, concentrations of lead and chromium in edible muscle tissue pike did not show significant difference between stations (P>0.05). The lead and chromium standards in American Food and Drug Administration (FDA), World Health Organization (WHO) were compared. The results showed that compared with the standard WHO= 0.5 toxicity of lead in samples of West wetland was observed more than permissible limit that this could be a warning of a threat to the health of these fish in vulnerable groups of society.

The aim of this study was to investigate the effects and antioxidant levels of green tea extract on sensory quality of minced silver carp during refrigerated storage at 4 ° C. Minced meat was packed with 0, 800 and 1000ppm concentrations of aqueous extract of green tea and stored at refrigerator temperature.Minced meat was packed with 0, 800 and 1000ppm concentrations of aqueous extract of green tea and stored at refrigerator temperature.Evaluators measured sensory evaluation indices (odor, taste, texture, and total utility) on days 0, 4, 8, 12 and 16. Results of sensory evaluation showed significant increase in sensory properties of minced silver carp during storage. According to the results of this study, minced meat treated with 1000 ppm extract was consumable compared to other treatments up to the end of storage period and improved the sensory characteristics and overall acceptability of the samples.

Microbial contaminants entering the aquatic environments can endanger the health of swimmers, sailors, tourists, fishermen, fish cage culture personnel, as well as the production and quality of aquatic food. In the present study, some bacterial contamination characteristics of Hassanlu Reservoir Lake were investigated for fish cage culture monthly at different sites (stations 1, 2 and 3: the south shore of the lake / the villages adjacent to Hasanlu; station 4: the dam’s exit; stations 5, 6 and 7: the north shore of the lake / the Mahabad-Urmia road; station 8: the middle of the lake where cage culture of rainbow trout were installed; and station 9: the mouth of the Godar River) during April 2017 to March 2018. The results showed an increase in total and fecal coliforms as well as E. coli contamination in seasons with higher temperature. The amount of microbial load in the upstream station – station 9- (river inlets) and also the station 1 (rural area) were greater than the middle and crown stations of the Hasanlu reservoir lake. The microbial indices of Hassanlou lake indicated that if other biological and non-biological factors are in the range of bio-economic life of cultured fish, it would be suitable for fisheries exploitation such as catching and culturing of narrow-clawed crayfish (Astacus leptodactylus), however, caution should be exercised about culturing of edible oysters and aquatic life and cage culture. Therefore, it is suggested that management and monitoring programs be adopted with the cooperation of all relevant agencies to prevent or reduce the entry of various pollutants into these water bodies so that in the future the potential of Hasanlu Lake to develop other aquaculture production, and to reduce fishing pressure in water bodies as well as to help sustainable production and job creation in the region.