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This study was conducted to determine growth parameters, catch and fishing effort trends and stock assessment of mullets in the Iranian coastal waters of Caspian Sea in the years 2015-2016 and 2016-2017. According to the result, the numbers of beach seines were 123 and 120 and their fishing efforts were observed 43588 and 42230 beach seining, respectively. The total catches (including illegal fishing) were also obtained 1542 mt and 2505 mt during 2015-2016 and 2016-2017, respectively. The mean (± SD) of fork length were observed 33.4±5.24 and 33.3±5.72 cm and for total weight were 395.8±142.8 and 395.5±264.52 g in 2015-2016 and 2016-2017, respectively. The frequency of immature individuals were observed 14.2 and 15.7 percent during two sampling period, respectively. The range of age was from 2 to 11 year and fish with 4 to 6 years comprised up to 75.4 and 70 percent, respectively. In fork length – weight relationship a and b were calculated 0.029 and 2.690 for 2015- 2016 and 0.0207 and 2.7914 for 2016-2017, respectively. The Growth parameters of golden gray mullet were K=0.16/yr, L∞ = 64.3 cm, t0 = -0.26/yr. The total and naturaly mortality, Z and M, were calculated 0.81 and 0.35, respectively. Based on catch-at-age data, in the years 2015-2016 and 2016-2017, the total biomass, from the biomass-based cohort analysis were estimated 8170 mt and 7960 mt for golden gray mullet, respectively. In the years 2015-2016 and 2016-2017, the instantanuse fishing mortality F, were 0.25 and 0.46 year-1 and explotation ratio were 0.46 and 0.57, respectively. Iranian Fisheries Science Research Institute Published

This study focused on identification phytoplankton, zooplankton, benthos, fishes and relationship between biotic and abiotic parameters at three stations in the Kan river during 2014. This study identified 19 phytoplankton taxa. The findings showed, the diatoms abundance were dominated in the river. The chlorophytes abundance were recorded the lowest abundance in this study. The nutrients and water temperature were the significant abiotic parameters to increase cyanophytes and chlorophytes abundance in the Kan river. This study identified 26 zooplankton taxa. The Rotatoria and Protozoa abundance were dominated in the Kan river. Based on CCA, there was no correlation between abundance zooplankton and abiotic parameters. The biodiversity index of plankton was between 1.8 and 2 and the lake situation is located in the mesotrophic category. The study of the Kan river fishes showed, only one endemic fish species Capoeta bohsei. The length (between 38 and 270 mm, average 144±86 mm) and weight (between 1.1 and 356 g, average 108.8±146.7 g) of the C. bohsei were varied during the study period. The 19 benthos taxa were identified. The Ephemeroptera was most abundant in the benthos groups. The classification of river based on biology indicator and environmental parameters confimed that water quality is located in the moderate category. Iranian Fisheries Science Research Institute Published

This study focused on identification phytoplankton, zooplankton, benthos, fishes and relationship between biotic and abiotic parameters at three stations in the Kan river during 2014. This study identified 19 phytoplankton taxa. The findings showed, the diatoms abundance were dominated in the river. The chlorophytes abundance were recorded the lowest abundance in this study. The nutrients and water temperature were the significant abiotic parameters to increase cyanophytes and chlorophytes abundance in the Kan river. This study identified 26 zooplankton taxa. The Rotatoria and Protozoa abundance were dominated in the Kan river. Based on CCA, there was no correlation between abundance zooplankton and abiotic parameters. The biodiversity index of plankton was between 1.8 and 2 and the lake situation is located in the mesotrophic category. The study of the Kan river fishes showed, only one endemic fish species Capoeta bohsei. The length (between 38 and 270 mm, average 144±86 mm) and weight (between 1.1 and 356 g, average 108.8±146.7 g) of the C. bohsei were varied during the study period. The 19 benthos taxa were identified. The Ephemeroptera was most abundant in the benthos groups. The classification of river based on biology indicator and environmental parameters confimed that water quality is located in the moderate category.

This study was conducted to determine growth parameters, catch and fishing effort trends, stock assessment and Acceptable Biological Catch (ABC) of bony fishes in the Iranian coastal waters of Caspian Sea in the years 2013-2014 and 2014-2015. According to the result, the numbers of beach seines were 124 and 120 and their fishing efforts were observed 44688 and 46299 beach seining, respectively. The total catches (including illegal fishing) were also obtained 17144.3 mt and 16733.2 mt during 2013-2014 and 2014-2015, respectively. The highest proportion of catch was belonged to kutum and golden grey mullet (94.4% and 89.5%, respectively) in two fishing seasons mentioned above. Growth parameters of kutum were estimated as K=0.19/yr, L_∞ = 61.3 cm, t0 = -0.99/yr. The Growth parameters were K=0.18/yr, L_∞ = 61.1 cm, t0 = -0.14/yr for golden gray mullet and were K=0.14/yr, L_∞ = 70.8 cm, t0 = 0/yr for common carp. Based on catch-at-age data, in the years 2013-2014 and 2014-2015, the total biomass, from the biomass-based cohort analysis were estimated 46900 mt and 41000 mt for kutum and 11550 mt and 12670 mt for golden grey mullet, respectively. The reference points of F0.1 and F35% were 0.41/yr and 0.34/yr for kutum and 0.36/yr and 0.33/yr for golden grey mullet, respectively. According to catch of species/groups, three main groups can be divided easily. The one–way ANOSIM catch similarity test indicated that coverage rates of different years were homologous and similar, but the coverage rates of different months, regions and periods were not similar. Also, there were significant differences in community composition of fishes in catch of beach seines among three times; three durations; three regions and seasons (in all cases MRPP, p

Caspian trout (Salmo trutta caspius ) is one of the migratory fish species which lives and feeds in the Caspian Sea .This species distributed in south and western of the Caspian Sea . In order to rehabilitation of the Caspian trout in western area, the operation of the project started from the beginning of the fishing season of the 20112012. Specimens of the Caspian trout obtained from beach seine cooperatives and have been transferred to the fish farm in Asalem region .Totally, 44 specimens of the Caspian trout has been caught in two month period .Most of the fishes was from Kargan roud river . The mean length and weight of the brood fishes were 67.7 cm and 3122.7 g respectively .As at present Shilat uses just the broods of the Tonekaboon region for restocking of this species ,we recommend to use the broods of the western region separately for rehabilitation of the stocks of this region .

Experiments were conducted to evaluate the effects of different dietary levels of protein (%30,%35,%40,%45) , fat (%8,%12,%16,%20) and total energy (3500,4000,4500,5000 kcal/kg ) on growth of fingerling Roach (Rutilus rutilus caspicus knipowitschi ) in four treatments with triplicates. The crude protein of experiment, fish averaged 2.60 gr stoking density of 25 fish/tank in a during of 57 days, the crude fat of experiment, averaged 5.30 gr stoking density of 15 fish/tank in a during of 67 days and the gross energy of experiment, averaged 5.30 gr stoking density of 25 fish/tank in a during of 57 days which reared into 100L-fiber glass tanks. At the end of each experiments, growth average parameters, such as weight gain(%), specific growth rate, food conversion ratio, condition factor and survival (%) were not significantly different among all treatments (P>0/05) but protein efficiency ratio showed in fish fed of %30 and %35 protein at levels significantly different with another treatments (P

This study was conducted to determine growth parameters, catch and fishing effort trends, stock assessment and Acceptable Biological Catch (ABC) of bony fishes in the Iranian coastal waters of Caspian Sea in the years 2013-2014 and 2014-2015. According to the result, the numbers of beach seines were 124 and 120 and their fishing efforts were observed 44688 and 46299 beach seining, respectively. The total catches (including illegal fishing) were also obtained 17144.3 mt and 16733.2 mt during 2013-2014 and 2014-2015, respectively. The highest proportion of catch was belonged to kutum and golden grey mullet (94.4% and 89.5%, respectively) in two fishing seasons mentioned above. Growth parameters of kutum were estimated as K=0.19/yr, L_∞ =61.3 cm, t0=-0.99/yr. The Growth parameters were K=0.18/yr, L_∞= 61.1 cm, t0= -0.14/yr for golden gray mullet and were K=0.14/yr, L_∞= 70.8 cm, t0= 0/yr for common carp. Based on catch-at-age data, in the years 2013-2014 and 2014-2015, the total biomass, from the biomass-based cohort analysis were estimated 46900 mt and 41000 mt for kutum and 11550 mt and 12670 mt for golden grey mullet, respectively. The reference points of F0.1 and F35% were 0.41/yr and 0.34/yr for kutum and 0.36/yr and 0.33/yr for golden grey mullet, respectively. According to catch of species/groups, three main groups can be divided easily. The one–way ANOSIM catch similarity test indicated that coverage rates of different years were homologous and similar, but the coverage rates of different months, regions and periods were not similar. Also, there were significant differences in community composition of fishes in catch of beach seines among three times; three durations; three regions and seasons (in all cases MRPP, p

This study was carried out about 15 months to determine suitable locations for the development of aquaculture across the Gamasiab river of Hamedan province in 2007 - 2008. Physicochemical parameters and macro benthic invertebrates fauna 15 and 13 stations respectively every 45 days and seasonally fish identify in 8 stations were performed according standard methods. The average water temperature was 12.8±3.7 oC, minimum and maximum dissoled oxygen were 2.6 and 12.5 mg/lit respectively during the study. The pH range was between 7.5-8.8 , the minimum and maximum Ec was 250 and 750 µmos/cm in Mehr and Tir. The transparency range was recorded about 1-103 F.T.U. The uder factors such as amount of suspended materials: 0.01-0.1 mg/l, amount of BOD5: 0.05-6.2 mg/l and COD: 30 (minimum) and 70.57 (maximum) were recorded. The total solids material (T.S.S) were less than 1 mg/lit. Totally 37 groups of bentic organisms were identified which 11 groups of them were appertained to pollution sensitive orders containing Ephemeroptera, Trichoptera and Plecoptera. During fish population studied 21 species belonging 5 family were identified. Based on obtained results of biological, ecological, economic and social parameters, 10 sites in 7 areas were suitable identified for fish rearing and 12 aquaculture programs (10 plan for fish rearing and 2 plan for increasing fish production of (Oncorhynchus mykiss). The minimum and maximum production capacity in mentioned places was estimated about 1675 and 3850 tons respectively.

Caspian trout (Salmo trutta caspius ) is one of the migratory fish species which lives and feeds in the Caspian Sea .This species distributed in south and western of the Caspian Sea . In order to rehabilitation of the Caspian trout in western area, the operation of the project started from the beginning of the fishing season of the 20112012. Specimens of the Caspian trout obtained from beach seine cooperatives and have been transferred to the fish farm in Asalem region .Totally, 44 specimens of the Caspian trout has been caught in two month period .Most of the fishes was from Kargan roud river . The mean length and weight of the brood fishes were 67.7 cm and 3122.7 g respectively .As at present Shilat uses just the broods of the Tonekaboon region for restocking of this species ,we recommend to use the broods of the western region separately for rehabilitation of the stocks of this region . Iranian Fisheries Science Research Institute Published

This study was carried out about 15 months to determine suitable locations for the development of aquaculture across the Gamasiab river of Hamedan province in 2007 - 2008. Physicochemical parameters and macro benthic invertebrates fauna15 and 13 staitions respectively every 45 days and seasonally fish identify in 8 stations were performed according standard methods. The average water temperature was 12.8±3.7 oC, minimum and maximum dissoled oxygen were 2.6 and 12.5 mg/lit respectively during the study. The pH range was between 7.5-8.8 , the minimum and maximum Ec was 250 and 750 µmos/cm in Mehr and Tir.The transparency range was recorded about 1-103 F.T.U. The uder factors such as amount of suspended materials: 0.01-0.1 mg/l, amount of BOD5: 0.05-6.2 mg/l and COD: 30 (minimum) and 70.57 (maximum) were recirded. The total solids material (T.S.S) were less than 1 mg/lit. Totally 37 groups of bentic organisms were identified which 11 groups of them were appertained to pollutionsensitive orders containing Ephemeroptera, Trichoptera and Plecoptera. During fish population studied 21 species belonging 5 family were identified. Based on obtained results of biological, ecological, economic and social parameters, 10 sites in 7 areas were suitable identified for fish rearing and 12 aquaculture programs (10 plan for fish rearing and 2 plan for increasing fish production of (Onchorhynchus mikiss).The minimum and maximum production capacity in mentioned places was stimated about 1675 and 3850 tons respectively. Iranian Fisheries Science Research Institute Published

This research was carried out over a period of 60 days in the summer and autumn of 2005 in the Caspian Sea Aquaculture Research Station (Inland Water Aquaculture Research Center). Fingerlings of Rutilus frisii kutum weighting one gram were transferred to fiberglass 100 liter tanks each stocked with 35 fish. The fish were divided into five groups and treated with five treatments and three replicates including, fresh water, 4ppt, 6ppt, 8ppt, and 10ppt salinity by completely randomized design. We found that different salinities did not affect the mortality rate of the fish. Comparison of food conversion ratio (FCR), special growth rate (SGR) and weight gain (WG) between control and other treatments revealed a significant difference (p£0.05). We also found that the 4ppt treatment differed meaningfully with 8ppt and 10ppt treatments in terms of FCR, SGR and WG (p£0.05) and the same was true between 6ppt and 8ppt and 10ppt treatments for the FCR, SGR and WG. The results showed that the maximum and minimum weight gain were related to 10ppt treatment (mean 58.9±2.71) and control (mean 39.1±4.73) respectively. The minimum special growth rate (0.549±0.057) was referred to the control treatment and the maximum (0.772±0.028) was seen in 10ppt salinity. The minimum average FCR (3.93±0.122) was seen in 10ppt salinity and the maximum (5.6±0.601) was observed in the control treatment. According to the results, it is suggested that the optimal salinity for fingerlings with mean weight 1gr is 8ppt and 10ppt.

Caspian sand goby, Neogobius jluviatilis pallasi belongs to Gobiidae family. Because of their abundance in Caspian Sea, they have important role in the sea food chain in this area. This study was conducted from October 2005 to September 2006 in southwest coasts of the Caspian Sea in Guilan province. Samples were collected monthly from four stations (Astara, Anzali, Chamkhaleh and Chaboksar coasts) from coastal areas to waters 15meters deep using bottom trawl. Result of differential function analyses on corrected morphometric statistic showed three functions 51.3%, 28.4% and 20.3%, respectively, and sum of differentiative function percentage was 80% which proved difference among groups. The functions showed that samples in Astara station were completely different from other regions while they were similar to Anzali station only in some sampling points. Chamkhaleh and Astara stations were the same but Chaboksar station was a separated group. Analysis of differential functions for studied characteristics included on average 86.3% of the population with most of it belonging to Astara station (93.3%) and Anzali (90%). The minimum amount belonged to Chamkhaleh with 79.3%. The results showed that Neogobiusjluviatilis pallasi probably has three different populations in Astara, Anzali, Chamkhaleh and Chaboksar populations.

Three experiments carried out to determine optimize level of crude protein, lipid and gross energy requirements of Kutum fish (Rutilus frissi kutum) fingerling. A completly randomized design consisted of 4 treatments with triplicates which those was used with four experimental dietary crude protein levels (35, 40. 45 and 50% CP), Four crude lipid levels (8, 12, 16 and 20%) and four gross energy levels (4250, 4500, 4750 and 5000 k cal/kg of diet) being tested separately. Kutum fish fingerling averaging 1067 ± 98 mg,,2378 ± 185 mg, and 1067 ± 143 mg respectively and stocked with density of 20 fish at volum 80 liters. Fish fed with 3% of wet body weight at three times, 9 am, 12 am and 4 pm. The following performance parameters were evaluated final weight, weight gain, feed intake, feed conversion ratio, specific growth rate, protein effieciency ratio and condition factor. Fish fed diets 40% CP, 20% CL and 4500 K Cal/kg Gross energy could meet the nutritional requierments of kutum fish fingerling. Iranian Fisheries Science Research Institute Published

Three experiments carried out to determine optimize level of crude protein, lipid and gross energy requirements of Kutum fish (Rutilus frissi kutum) fingerling. A completly randomized design consisted of 4 treatments with triplicates which those was used with four experimental dietary crude protein levels (35, 40. 45 and 50% CP), Four crude lipid levels (8, 12, 16 and 20%) and four gross energy levels (4250, 4500, 4750 and 5000 k cal/kg of diet) being tested separately. Kutum fish fingerling averaging 1067 ± 98 mg,,2378 ± 185 mg, and 1067 ± 143 mg respectively and stocked with density of 20 fish at volum 80 liters. Fish fed with 3% of wet body weight at three times, 9 am, 12 am and 4 pm. The following performance parameters were evaluated final weight, weight gain, feed intake, feed conversion ratio, specific growth rate, protein effieciency ratio and condition factor. Fish fed diets 40% CP, 20% CL and 4500 K Cal/kg Gross energy could meet the nutritional requierments of kutum fish fingerling.