Iranian Scientific Fisheries Journal
Year:2020 | Volume:29 | Issue:1 |Papers Count:20

Determining the relationship between biotic and abiotic factors and their effects on water quality and eutrophication plays important roles in managing and optimizing the efficiency of dams. Therefore, in the present article, the above relations with emphasis on the results of one-way and multivariate statistical analysis were investigated in Sanandaj Azad dam. Monthly Sampling was carried out in 5 stations in 2015-2016. All environmental parameters (Water temp., Secchi disk, Turbidity, pH, DO, DO%, BOD5, COD, EC, NO3-, PO43-, Chl-a) and microbs (Total counts, Total coliform, Fecal coliform and Fecal Streptococcus) were analyzed based on standard methods. (According to the results, low numbers (less than 0. 1 CFU / 100 ml), of streptococcus and fecal coliform in all samples were a good sighn of fine water quality in terms of non-contamination with fecal (resistant and old) and (fresh) microbes. In the step wise linear regression test, the coefficient effect of trophic state, based on chlorophyll-a and transparency depth on the total trophic index was obtained more than the nutrients trophic index. According to the principal component analysis (PCA), the trophic state index and chlorophyll-a concentration (in the first component) were the most important factors on quality of the water. While the water quality index and its parameters (inorganic phosphorus, BOD5 and coliform) were included in the second component. Among the environmental parameters affecting the quality of water, the percentage of saturated dissolved oxygen and then BOD5 were in the first priority. As a conclusion, according to the the trophic state index, this dam is suitable for the development of rough fish (cyprinidae). In other words, according to the WQI index, the Azad Dam is suitable for farming of salmonids fish, but based on trophic stae index, condition is not very favorable.

In order to make more use of non-oil exports potential of Iran, factors affecting the export of fishery products were identified by searching in library resources as well as interviewing with experts. After designing the questionnaire, its validity was confirmed by the exporters and experts. After completing the questionnaire, the data was analyzed by 35 statistical samples using Garrett ranking technique. The most important factors affecting the export of fishery products include improving international trade relations, reforming domestic customs laws and regulations, reducing production cost and inflation, increasing standards of production and processing, the possibility of attracting foreign investment, observing regulations and standards destination's quality and health, effective presence and special promotions in global markets, identifying and providing information on target export markets, and government support and oversight, respectively. Thus, the government, with its strong support from the fish exports sector, can attract international investment, improve international relations, and reduce inflation and production cost. Also, the field of reforming customs regulations, adequate knowledge and presence in export markets and regulations will also help to improve and increase exports.

This research was conducted to evaluate the effect of ecological factors on diversity and density of phytoplankton in Caspian Sea. Sampling was carried out from 5 stations included of Ramsar, Nowshar, Noor, Fereydunkenar and Miankaleh (Amirabad) regions (surface, 3 and 5 m depths) from 2016 to 2017. The totals of 56 species belong to 5 phyla of algae division were identified which maximum density and biomass were observed in Skletonema costatum, Thalassionema nitzschioides, Nitzschia acicularis, Pseudonitzschia seriata and Melosira moniliformis. Density and biomass of phytoplankton showed that the mean of biomass was 12. 3± 2. 7×106 cell/m3 and 35. 6± 7. 7 mg/m3, respectively, with the highest average density in winter (19. 1± 4. 4 ind. m-3). The highest and lowest Shannon index was 1. 97 and 1. 84 in different seasons respectively. Silica, temperature and inorganic nitrogen play an important role in density of algae especially diatoma, cyanophyta and pyrrophyta. The recent study showed that a high N: P ratio in winter and characteristics along with a suitable strategy for Chlorophyta species are important and desirable reasons for increasing their populations.

Aeromonas hydrophila bacterium causes septicemia in saline and fresh water fishes. One of the most important problems in the field of health management in some fish farming centers is controlling the bacterial septicemia syndrome caused by this bacterium. The purpose of this study was to find a way to control and eliminate the bacteria using bacteriophage to increase the survival rate of rainbow trout, infected with Aeromonas hydrophila bacteria. 360 rainbow trout with 15± 2 gr weight were selected among 15 groups with 3 replicates during 2018-19. They were contaminated with a concentration of 10-4 and 10-8 Aeromonas hydrophila (prepared from stock containing 1. 5× 108 CFU / mL, both intraperitoneally and immersed in water. Then they were exposed to 10-3 PFU/ mL AHɸ 3 bacteriophage isolated from rainbow trout farming pools of Kerman province. Temperature, pH, Oxygen, Salinity was controlled for all treatments. There was a significant difference between the control group and the treatments in both cases (intraperitoneal injection and immersion) (P ≤ 0. 05). The results indicated that the highest effect of bacteriophage on survival rate and reduction of rainbow trout losses was observed when the concentration of 10-8 bacteria and 10-3 PFU/ mL bacteriophage AHɸ 3 were immersed. The data were analyzed using SPSS 21 software and Duncan statistical test. Suitable and applied to increase the survival rate of rainbow trout against disease bacteria is the use of bacteriophages. This study emphasizes the need for further research into the use of phage therapies in the aquatic environment as an antimicrobial strategy that presents various aspects from an environmental and health perspective.

This research was conducted to study the phenotypic plasticity of the body shape in Carassius gibelio inhabiting lentic and lotic water bodies using geometric morphometric technique. For this purpose, a total of 119 specimens were collected from Sefid River (n=30), Alagol Lake (n=37), Khoda-Afarin dam Lake (n=21) and Mashkil River (n=31). To extracting body shape data in geometric morphometric method, the left side of specimens were photographed and 15 defined landmark-points were digitized on 2D images using TpsDig2 software. Data after general procratus analysis was analyzed using PCA, CVA, MANOVA and cluster analysis. The results showed a significant differences in the body shape between studied populations (p<0. 001). Based on the results, populations of the Alagol and Khoda-Afarin dam lakes had deeper body and smaller head, and those of Sefid River had deeper body, but similar to the Mashkil population had larger head. In addition, Alagol and Khoda-Afarin dam lakes populations were placed together in same clad and those of the Sefid and Mashkil rivers in another clade, indicating the separation of populations inhabiting lentic and lotic habitats. The results also showed that the body shape of C. gibelio changes based on type of type of habitat.

Direct mitochondrial DNA (mtDNA) control region sequencing analysis was used to investigate population genetic structure of Persian sturgeon (Acipenser persicus) in the Caspian Sea. A total of 45 specimens were collected from different locations of the Caspian Sea. mtDNA control region was amplified using PCR. Direct sequencing was performed according to a standard method. The results showed that 12 haplotypes were observed among 45 samples in the method. The highest numbers of haplotypes were observed in the Sefidrud River in which 3 haplotypes A, B and E among them were specific for the river and were not observed in the other locations. The average haplotype diversity (h) and nucleotide diversity (π ) were 0. 795± 0. 037 and 0. 0062± 0. 0046, for control region sequencing, respectively. The results of Fst based on kimura-2 parameters method and analysis of molecular variance (AMOVA) demonstrated that most variations occurred among the samples, and between samples of the Sefidrud and Russia and Azerbaijan are statistically significant (P<0. 0001). Therefore, three distinct populations including Sefidrud, Russia and Azerbaijan were identified. As mtDNA control region is a highly variable segment, it may be used as a potential marker for identifying populations and for determining their management and conservation units, leading to the useful application of molecular markers in investigating conservation genetics of the Persian sturgeon.

Biodiesel methyl ester or ethyl ester is a natural oil that is very similar to diesel and can be used as an alternative fuel for diesel engines. Micro-algae are able to produce and store high amounts of lipids. In this research, the production of biodiesel fuel from microalgae was investigated in a biofilm and some of its physical and chemical properties were determined. this study, a mixture of microalgae cultured from stagnant water was compared in a photobioreactor at two light intensities of 8000 and 16000 lux and the amount of biomass produced. The biomass produced under the light intensity of 8000 lux after isolation and drying was subjected to a direct trans-esterification process and biodiesel was produced. Analysis of biodiesel constituents of fatty acids was determined using GC / MS. Some biodiesel characteristics, such as density, cloudy point, spin point, and freezing point, were also studied. The light intensity of 8000 lux was superior to the magnitude of doubling of cells, specific growth rate and biomass production compared to 16000 lux light intensity, and was used to produce microalgae biomass. The results of GC / MS showed that biodiesel resulting from transesterification of lipid micro-algae contained 50. 31% saturated fatty acid and 49. 69% unsaturated fatty acid. Pallic acid saturated fatty acids (C16: 0) with 39. 16%, acetatanic acid (C18: 0), 65. 6%, arachidic acid (0. 72% C20: 0%), margaric acid (0. 17% C17: 0%) and acids The unsaturated linoleic fat (C18: 2) with 27. 47%, acidulic acid (C18: 1) with 20. 04 and palmitoleic acid (C16: 1) formed 25. 2% biodiesel. The produced biodiesel was 0. 853 g / cm3 and the cloud was cloudy and its dropping point was 3-and 10 ° C. The results of the study showed that the microalgae culture in the photobiovert can be minimized by minimizing the cost and time. Also, fatty acid profiles and biodiesel physical properties indicated that the micro-algae biodiesel was of high quality and direct steady-state exchange could be a good option for producing biodiesel, as compared to other methods.

The biodiversity of fish in the rivers is affected by various environmental factors. Occasionally, the severity of these environmental impacts is such that it leads to undesirable habitats for fish species and reduces biodiversity. The present study aimed to determine the most important environmental factors affecting the biodiversity of fish in the Zarineh River. For this purpose, in September 2018, seven stations were selected for fish sampling along the Zarineh River. Fish sampling from each station was carried out at 30 m with 3 replications (90 m in total) along the river according to the one-way method using an electrofishing device. In addition, environmental factors including water temperature, velocity, discharge, depth and altitude/elevation above sea level were also recorded at all stations. In total, 404 specimens were caught from the Zarineh River that belonged to 11 species. In this study, diversity indices including shannon– wiener, margalef, simpson, species richness, dominance and evenness were determined using Biodiversity Pro and PAST softwares. Canonical Correspondence Analysis was used to determine the environmental factors affecting the biodiversity and fish species. Based on the results, temperature, altitude/elevation above sea level, and water velocity were identified as environmental factors affecting the biodiversity of fish in the Zarineh River, respectively. In addition, depth, velocity and discharge were also identified as the most effective environmental factors on the abundance of fish species.

The aim of the present study was to evaluate alpha lipoic acid (ALA) supplementation as an antioxidant source. In this experiment, rainbow trout with average weight of 22. 16 ± 0. 02 g were studied in four treatments with three replications for eight weeks. Experimental diets included control (non-supplemented commercial diet), 500 mg/ kg ALA, 1000mg/ kg ALA and diets containing 1500 mg/ kg ALA. After eight weeks, growth parameters, fish muscle composition, levels of glutathione-Stransferase (GST), glutathione (GSH) and catalase (CAT) activity were measured in muscle, liver and intestine. The results of growth factors showed that percentage of weight gain, length increase and specific growth rate were significantly (p<0. 05) different between treatments and highest in 500 and 1000 mg/ kg ALA. Results of rainbow trout carcass fed with ALA showed a significant difference in protein and dry matter (p<0. 05), and treatment containing 1500 ALA concentration showed the highest carcass protein and dry matter. In addition, the effect of different concentrations of alpha lipoic acid on the activity of GST, GSH and CAT enzymes in muscle, liver and intestinal tissues was significant (p<0. 05). In muscle, CAT increased with increasing ALA concentration. Also, the highest and lowest amounts of GSH and GST were observed at 1000 and control concentrations, respectively. In the intestinal and liver tissues, the activity of GSH, GST and CAT enzymes was higher in treatments containing ALA. Considering the results of growth, increase of carcass protein and improvement of antioxidant enzymes activity by ALA, it is recommended to use this supplement at a concentration of 1000 mg/ kg.

One of the most useful methods of increasing resistance through impact on the aquatic immune system is trying to boost the immune system through various ways such as vaccination and the use of immune enhancers such as immune stimulants, probiotics and glucan compounds etc. Modern fish farming systems are common. The use of immunostimulants in gnotobiotic system is one of the new methods to prevent and control the aquatic diseases by realizing the mechanisms involved in hostmicrobe interactions. This study was designed to investigate the effect of zymosan immunostimulant on Artemia fransiscana growth and resistance to Vibrio campbellii and Vibrio proteolyticus infections in a gnotobiotic system. Artemia nauplii were fed with killed LVS3, about 10. 5×109 cells per falcon tube per day (control). Zymosan was added in an amount of 30. 6 mcg per falcon tube daily in experimental treatments. On the third day, V. campbellii and V. proteolyitus pathogens were added at 5 ×10 6 cell /ml. On the sixth day of the experiment, zymosan increased the percentage of daily survival against V. campbellii (54. 49± 1. 53) compared with control (31. 72± 9. 87), relative percentage of survival (80± 0. 08) compared with control (47± 0. 17) and total biomass production (21. 17± 0. 18) compared with control (9. 04± 4. 46) (p<0. 05). Although zymosan increased the percentage of daily survival, the relative percentage of survival and total biomass production against V. proteolyticus compared with the control, but the differences were not significant (p>0. 05). Zymosan also had positive impact on the individual length of challenged artemia with V. campbellii and V. proteolyticus, however that was not significant compared with the control (p>0. 05). In conclusion, the results revealed that the zymosan as an immunostimulant could increase the artemia resistance against vibrio infections in gnotobiotic environment.

Recently use of Acidifier (group of organic acids) increased in aquaculture. The purpose of this study was to evaluate the effects of acidifier (sodium diformate and citric acide) on growth performance, nutrition indices, immune and hematological parameters of the juvenile Oncorhynchus mykiss. A total of 630 juvenile Oncorhynchus mykiss (16. 55± 0. 72) randomly divided into seven experimental treatments (Three replicates each). All groups fed with experimental diet for 60 days. Bioassay conducted in first day and after sixty days and then growth parameters were investigated. Eexperimental diets were contain 0. 2, 0. 4 and 0. 6% sodium diformate (NDF) and 0. 2, 0. 4 and 0. 6%, combination of NDF and citric acid with equal ratio. Diet control was without acidifier. Results showed that almost all growth and hematological parameters were increased in fed groups with 0. 2% supplemented food with NDF and citric acid compare to the control group. The best FCR showed in the groups fed with 0. 2% (P<0. 05). Although haematological parameters of fish in groups fed by 0. 2, 0. 4 and 0. 6%, NDF and citric acid changed significantly after 60 days of feeding with experimental, no changed were observed in WBC value among the groups (P>0. 05). The results show that the immunological parameters including, total serum protein, immunoglobulin and bactericidal activity serum were affected significantly at Acidifier (p<0. 05) while Lysozyme activity serum and albumin was not affected (P>0. 05). The results of this study indicated that 0. 2%, NDF and citric acid in the diet could be a useful food supplement and can be used to improve the growth parameters and immunity system in juvenile Oncorhynchus mykiss.

To investigate the effect of red spicy pepper on growth, blood parameters and immune responses of rainbow trout, 240 fingerlings (mean weight 15. 69± 0. 33 g) were randomly distributed into 12 tanks (20 individuals per tank) and they were fed with 0, 1, 3, and 5% red chili pepper (Capsicum annuum) powder in their diet (each with three replicates) for 45 days. The results of growth indices showed that the highest level of body weight gain and specific growth rate were observed in 5% treatment compared to the other treatments (P<0. 05). The lowest value of the feed conversion ratio was observed in treatments fed 3% and 5% red pepper. In addition, no significant differences were observed in the condition factor among the treatments (P<0. 05). The highest survival rate was observed in 3% and 5% pepper treatments and this index was not significantly different between the treatment 1 and control (P<0. 05). The highest number of red blood cells was observed in 3 and 5% treatments (P<0. 05). The highest percentage of hematocrit was observed in 5% pepper treatment (P<0. 05). The highest white blood cell was related to the fish fed with red pepper-supplemented diets compared to the control group. The highest percentage of lymphocytes was observed in 5% pepper treatment. The highest levels of lysozyme activity, C3, and IgM were observed in 5% pepper treatment, which was significantly different from other treatments (P<0. 05). Also, C4 level significantly increased in the pepper-fed treatments (P<0. 05). Overall, supplementing rainbow trout diet with 5% spicy red pepper powder improved growth performance, nutrition efficiency and immune system of rainbow trout fry.

As one of the sub-sectors of agriculture and natural resources, Iranian fisheries has a significant contribution in the economy of the country. Recently, planning and investment in the fisheries sector have been difficult duo to the sharp fluctuations in price of products. This paper aims at determine and choosing the most appropriate fishery product price prediction model using autoregressive integrated moving average, time-delayed artificial neural network and combined pattern of the two above-mentioned methods. The data used in this research is related to the wholesale price of two products of the fishery (Seer fish and Black Pomfret fish), from April 2001 to September 2018. It was found that the ARIMA model showed a weak performance in predicting the price of both products in comparison with the artificial neural network method. And also, the hybrid method was more effective in forecasting the price of products than the other two methods. In conclusion, it is necessary to use nonlinear methods to forecast the prices of fishery products. Also, hybrid model can be used in longterm planning due to improved performance prediction with increasing forecast horizon.

Apparent digestibility of dry matter, crude protein, crude lipid and gross energy for fish meal (kilka fish meal, mixture fish meal, batch fish meal and south fish meal), some of the animal sources (poultry by product, meat and bone meal, blood meal cow), plant sources with high protein (wheat gluten and corn gluten) and plant sources with low protein (wheat meal, corn meal, canola meal, prepared soybean meal and soy bean meal) in juvenile Huso huso (160. 42 ± 23. 35 g) were investigated. Experimental diets were formulated based on 70% of the content of the reference diet and adding 30% of the ingridient test. One percent of chromium oxide was added as an indirect marker to all diets. Fish were reared in fiberglass tanks (500 L-1) for 8 weeks and fed satiation two times daily. Collction of settlement faecal were carrird out half or one hour after feeding via siphon deposited on the tank floor. Reslts indicated that Kilka fish meal had the highest protein digestibility (94%), but significant differences in the digestibility of batch, South and Combined fish meal (93 to 89%) with wheat gluten and corn (94 to 89%), prepared soybean meal and soybean meal (87% to 82%) and poultry by product (81%) were not found (P>0. 05). The highest lipid digestibility was found in batch fish meal (92%), followed by kilka fish meal (91%), south fish meal (90%), combined fish meal (89%) and poultry by product (83%) (P <0. 05). Current study showed that prepared plant sources have digestibility such as fish meal, although poultry by product and soy bean meal can be considered as a possible alternative to fish meal for the formulation of commercial diet in Huso huso juvenile.

In this study, specific weight and length growth and survival rates of Swordtail fish (Xiphophorus helleri) and Guppy (Poecilia reticulata) larvae using three feeding treatments including Daphnia pulex+O. africanum, D. pulex+O. africanum+Canola oil and D. pulex+Oscillatoria africanum+Fish oil were investigated. The results showed that the mean (± SE) specific growth rate of Guppy fish larvae were 6. 11± 0. 9, 5. 84± 1. 4 and 5. 6± 1. 2 g and for Swordtail fish larvae were 2. 3± 0. 4, 4. 14± 1. 7 and 4. 5± 0. 8 g, respectively. Also, the specific length growth rates of Guppy fish larvae were 1. 2± 0. 35, 1. 4± 0. 25 and 1. 1± 0. 3 cm and for Swordtail fish larvae were 1. 8± 0. 3, 2. 4± 0. 45 and 2. 6± 0. 6 cm, respectively. The survival rate (%) of Swordtail fish larvae were 35. 33, 41. 11 and 46. 62% while for Guppy fish larvae were 46. 12, 81. 41 and 94. 63%, respectively.

In the present study, the rise assessment of heavy metals includes copper(Cu), iron(Fe), cadmium(Cd), sternum(Sn), arsenic(As) and mercury(Hg) for the consumers of Indian white shrimp caught from different coasts of Chabahar was evaluated. In 2017, 180 shrimp specimens were caught from the coasts of Konarak, Beris and Gwadar (Chabahar Province). In the laboratory, the samples had dried, digested and subsequently the metals concentration was measured using spectrophotometer. The estimated daily intake of metals to the body of the consumers and the target hazard quotient were done based on the method, developed by the World Health Organization. Among different metals, iron had the highest concentration with 2. 72 μ g/g, while the lowest accumulation of metals was recorded for mercury with 0. 01 μ g/g. The ranking order of metals accumulation in the muscle of shrimp was as Fe, Cu, Sn, As, Pb, Cd, Hg. The highest amount of daily intake (μ g metal/kg person/ day) was observed for arsenic (0. 20) while the lowest was for Tin(sn) (0. 0006). Target hazard quotient (THQ) and total target hazard quotient (TTHQ) for all metals were lower than 1. The results showed there is not any health risk for the consumers of Indian white shrimp due to accumulation of copper, iron, cadmium, stannum, arsenic and mercury in the shrimp.