فصلنامه شیلات
سال هفتاد و چهارم شماره 4 (زمستان 1400)

Southern Caspian Kutum, Rutilus frisii kutum (Kamensky, 1901) is an important economic species in north of Iran. This study was conducted in order to identifying QTLs associated with growth traits, body weight and total length, in Caspian Kutum (R. frisii kutum) using microsatellites from close species, Common Carp (cyprinus carpio). The eleven full-sibs family were produced by mating between eleven male and eleven female that were collected from Sefid Rood river. Sampling was accomplished from broodstock caudal fin. Three month after hatch the offspring were collected and stored in alcohol 96%. Altogether 75 offspring were sampled. Genomic DNA was isolated from broodstock and offspring according to the protocol. With applying four microsatellite markers (HLJ2225, HLJ3366, HLJ3988, and HLJ2316) related to growth traits, altogether 10 loci, 13 genotype, were selected for performing statistical analyses. Genotyping was accomplished using AlphaEaseFC software. Statistical analyses were performed by GenAlEx 6.1, Arlequin ver. 3.5.2 and Excel 2013 softwares. Investigating the number of alleles per locus, effective number of alleles per locus, expected heterozygosity, observed heterozygosity, fixation index, polymorphic information content, R and F statistics, Hardy-Weinberg equilibrium showed that these loci, HL1, HL2, HL3, HL4, HL5, HL6, HL7, HL8, HL9 and HL10, were suitable for applying in marker-assisted-selection (MAS) program for Caspian Kutum (R. frisii kutum). The heritability was calculated for each locus, for total length and total weight. Then based on linkage disequilibrium five heritable linkage group, LG1, LG2, LG3, LG4 and LG5, were constructed for total length in Caspian Kutum (R. frisii kutum). The LG4 with eight loci (nine genotype), including loci HL3, HL4, HL5, HL6, HL7, HL8, HL9 and HL10, was selected for family linkage group selection (LGS). The LG4 had a relatively average heritability ( = 0/432). Altogether, six family based on LG4 were selected to use in R. frisii kutum selective breeding program. This study showed that using microsatellite markers related to growth traits in close species to Caspian Kutum (R. frisii kutum) can aid to identifying QTLs associated with growth traits in Caspian Kutum, an important commercial species.

An experiment was conducted to study the effect of feeding the various starch sources on body weight gain, feed conversion ratio, hepatosomatic, viscerosomatic indexes and some blood biochemical parameters of rainbow trout (Oncorhynchus mykiss). Wheat flour, corn and starch by-product from production of wheat gluten used in the extruded fish feed and fed to three hundred fish (average weight 157 ± 1 g) for 60 days, where distributed in 12 fiberglass tanks (300-liter) as a completely randomized design. The results showed that various dietary sources of starch did not impact feed intake, specific growth rate, and feed conversion ratio of fish in the total period. The lowest viscerosomatic index and the highest carcass efficiency of fish were seen by feeding corn extruded feed (P<0.05). Feeding the wheat flour increased the serum concentration of aspartate aminotransferase (P<0.05); while, triglycerides, cholesterol, total protein, glucose, high-density lipoprotein, and low-density lipoprotein were not affected by the experimental diet. Overall, corn could be completely replaced with wheat flour, as the main starch source of extruded feed without any adverse effect on growth performance and blood biochemical parameters of rainbow trout; while more research is needed to apply the starch by-product from production of wheat gluten in the fish extruded diet.

Dinor River is one of the tributaries leading to Gamasiab River in Tigris river drainage and one of the habitat of Kermanshah stone loach (Sasanidus kermanshahensis). The river has been affected by human activities such as agriculture. In this study, a total of 168 specimens were collected from 21 stations of Dinor River for the study of Kermanshah stone loach’s habitat suability index. For this purpose, the river characteristics, including water velocity (m/s), water depth (cm), altitude (m), river width (m), bedrock index, and average bedrock diameter (cm) were recorded at each station. The habitat suitability index was examined according to the relationship between environmental variables and species abundance. The results showed that river width and water velocity are directly related and altitude, water depth, and bed index were inversely related to the abundance of S. kermanshahensis. The HSI index with a value of 0.497 showed that this river has moderate suitability for this species. Also, the results indicated that the selected habitat of S. kermanshahensis includes areas with high water velocity due to the need for adequate oxygen, sand-mud bed, high width, low altitude, and shallow depth. The findings can be used to manage and protect the reserves of this species, which is part of the country's natural heritage..

Nowadays, due to the significant increase in the number of referrals of sick fish to aquatic animal specialists and clinics and the consequent increase in their contact with fish, the importance of the need to obtain the necessary knowledge and accurate and comprehensive information on how to prevent zoonosis disease's transmission from fish to human, is understood increasingly not only for aquatic professionals but also for all people involved in the field of aquaculture. One of the most well-known zoonose diseases among fish and humans, which is transmitted to humans through direct contact, is a disease caused by the invasion of mycobacteria called fish mycobacteriosis or tuberculosis. Mycobacteria are a group of aerobic, non-motile bacilli that are acid-alcohol resistant and grow slowly. They can cause prominent granulomatous nodules and extensive losses in fish. Exposure of human skin abrasions to sources contaminated with Mycobacteria can lead to the formation of different types of tuberculosis in humans. The clinical manifestation of this disease is often in the form of not so painful nodules with skin ulcers and scars in humans. A variety of methods such as culture, PCR, and preparation of histopathological sections can be used to identify and diagnose Mycobacteriosis. This study provided comprehensive information on the introduction, clinical signs, necropsy symptoms, pathological symptoms, transmission, diagnosis, control, treatment, and health considerations associated with fish Mycobacteriosis.

Biotic indices for water quality monitoring are useful tools for assessing the health of rivers and lakes. The aim of this study was to compare biotic indices using benthic macroinvertebrate to evaluate the water quality of Mubarakabad River, Minudasht, Golestan Province. Macroinvertebrate samples were collected seasonally from 4 stations in three replications using a Surber sampler with a coverage area (900 cm2) in 2020. A total of 2828 specimens of macroinvertebrate identified and classified into 8 orders and 12 families, of which Diptera with 4 families was the most diverse group of macroinvertebrate and the highest frequency belonged to Chironomidae (46.99%) and then Baetidae (22.52%). Spring with 39% had the highest and winter with 12% had the lowest frequency. The highest distribution of macroinvertebrate was obtained in station 4 (33%) and the lowest in station 1 (19%). The studied indicators were: 1) EPT (percent of Ephemeroptera, Plecoptera and Trichoptera); 2) BMWP (Biological Monitoring Work Party System); 3) ASPT (Average Score per Taxon); 4) HFBI (Hilsenhoff Family Biotic Index); and 5) the Shannon-Wiener and Simpson index. According to the cluster analysis of macroinvertebrate distribution among the stations, it showed two separate groups. The results of biotic indices showed that the Hilsenhof, BMWP and ASPT are suitable for assessing the water quality of the Mubarakabad River. Finally, water quality was assessed as good condition for the upstream station and poor condition for the downstream station. The results of a combination of biotic indices showed that stations located in rural and agricultural areas are more polluted than upstream stations and control and management of pollutant sources is necessary to protect the study area.   .

Macrobenthos are known as biological indicators of their living environments and can be used as index of water pollution in different water resources. Achiroud River located in Gillan province and its macrofauna has not been studied yet. So, in the present study, the macrofauna of the Achiroud River in the winter 2015 and spring 2016 was examined. Sampling was performed in two seasons of winter 2015 and spring 2016. Five stations were selected based on geographical characteristics of the river and each station using GPS system. Sampling was quadratic and seasonal. The Hilsenhoff index was determined based on the presence of benthos at each station. The water pollution was determined using the Hilsenhoff index in each station in spring and winter. The macrobenthos classified into 3 classes, 12 families and 14 species and identified. The most frequency was related to insects and the lowest frequency belonged to Malacostraca. The highest frequency in the winter belongs to the Gammaridae (Gammarus sp.) and in the spring belonged to the two families Gammaridae and Heptageniidae (Gammarus sp. and Ecdyonurus venosus). Species of Gammarus sp. and Ecdyonurus venosus were present at the most stations in two seasons. The highest value of Hillsenhof index was (5.22) observed in winter and the lowest value of this index was related to spring (0.71). According to the HFBI bio-index, water quality in stations 3 and 5 was excellent, in stations 4 was very good and in station 2 was intermediate.

The main objective of this study was to optimize the environmental conditions for maximum growth of Dunaliella salina algae. In this study, effective environmental parameters in algae growth, such as temperature in two levels of 18± °C and 28±2 °C, pH in three levels of 7.0, 7.5, and 8.0 and salinity seven levels of 0.5, 1.0, 1.5, 2.0, 2.5, 3, and 4 molar NaCl in a 30-day culture period were investigated. The dark: light cycle and the constant light intensity were considered 24:0 and 130 130 molPAR. m-2.s-1, respectively. Results depicted that an increase in temperature affecting specific growth rate and a decrease in cell’s population doubling time. The highest specific growth rate and the shortest cell’s doubling time were observed under the condition of pH = 7. Furthermore, the highest specific growth rate was obtained in the salinity of 1.5 molar (0.59 per day) while the lowest specific growth rate in the salinity of 4molar (0.04 per day). The shortest (approximately 1.5 day) and longest (from 10 to 19 days) cell’s doubling time were recorded in salinities of 1.5 and 4molar, respectively, such that by increasing salinity from 0.5 to 1.5 molar, doubling time decreased while by increasing salinity from 1.5 to 4 molar, the doubling time showed a decrease trend. The algae cell concentration increased by an increase in temperature. There were significant differences among cell concentrations in various pH levels. pHs higher and lower than 7.5 led to a decrease in cell concentration. Therefore, in most samples, the maximum cell concentration was observed at pH of 7.5. An increase in temperature when pH was 7.5 let cell concentration to reach its maximum amount faster. By increasing salinity from 0.5 to 1.5 molar, cell concentration increased. In comparison, an adverse effect was observed when salinity increased from 2 to 4 molar. Cell concentration in 1.5 molar salinity condition ranged from  to  and in 4 molar salinity, cell concentration varied from  to . Based on the results of this study, the optimum environmental condition for growth of Dunaliella salina recorded under the salinity = 1.5 molar, temperature = 28±2 °C, and pH = 7.5. Condition of 1and 2 molar salinities with the aforementioned temperature and pH, is suggested as the further option for production of this algae.

With the increase in production, consumption and processing centers of rainbow trout, the optimal use of the generated waste is very important. One of the ways to convert these wastes into high value-added products is to produce biosilage. The aim of this study was to investigate some of the chemical and microbial properties of biosilage produced from rainbow trout wastes as a suitable product for use in the livestock, poultry and fish feed industry. The results showed that the product has 52.27% protein and 8.3% fat. PV and TVB-N for biosilage were measured to be 2.61 meq/kg and 44.0 mg/100g, respectively. Logarithm total viable bacteria, coliforms, Fecal coliforms, Escherichia coli and mold and yeast count in the product were reported 8.78, 3.72, 1.18, zero and 3.23 per gram, respectively. The concentrations of manganese, copper, iron and zinc were 10.6, 13.7, 251.3 and 118.7 mg/kg, respectively in the produced silage. According to the results of the present study and comparison of these findings with other studies, it can be claimed that the biosilage produced in the present study is almost equivalent to other consumables for feeding livestock, poultry and fish in terms of indicators and characteristics and this product can be used as a suitable alternative to other common products used in the food industry.

Optimal aquaculture requires various criteria, among which the choice of food with the necessary potential is of particular importance. The aim of this study was to determine the effect of different levels of Spirulina platensis algae powder in shrimp diet on growth indices and survival percentage of Palaemon elegans shrimp larvae during a four week- culture period. The mean initial weight and length of post larvae were 0.0132 (g) and 6.88 (mm). Four diets consisting of the spirulina algae powder were prepared and substituted at 3, 5, 8 and 10 percent in a base shrimp diet as treatments and a control diet was without spirulina algae powder. Growth indices in the control treatment (without algae) had the lowest rate and was significantly different from treatments of 5, 3, 8 and 10 percent of spirulina algae (P<0/05). There was a significant difference between control and treatment fed with pure algae only in increasing total biomass (P<0/05). There was no significant difference between the group fed with pure algae and 3 percent treatment in the final length and increase of length (P<0/05), but the differences were significant in other growth indices with other treatments (P<0/05). The best growth indices were observed when shrimps were fed by 5 percent algae powder (P<0/05). in comparison between treatments of 3, 8 and 10 percent algae powder, the only significant difference observed in the final length, and an increase in length was detected in treatments 3 and 10 percent algae powder (P<0/05). Also, the survival rate in control treatment was significantly lower than other treatments (P<0/05). In general, based on the results of this study, the diet containing the 5 percent of spirulina algae powder showed the best results in the growth and survival of P. elegans shrimp post larvae.

In the present study, the effects of different levels of dietary antioxidant supplements on growth performance and biochemical indices in rainbow trout (Oncorhynchus mykiss) fingerlings were investigated. For this aim, nine experimental diets were formulated and supplemented with different combinations of three antioxidants including vitamin E (VE) at levels of 0, 100 and 150 mg kg-1 diet), coenzyme Q10 (CoQ10) at levels of 0, 10 and 20 mg kg-1 diet and selenium forms (mineral, organic and nano-selenium (Nano-Se)) at levels of 0, 0.3 and 0.5 mg kg-1 diet. The fish were randomly divided into these diets with stocking density of 25 per replicate and fed for 56 days. Based on the results, a relative increase was observed in the growth indices of fish fed with the treatment containing 0.5 mg Nano-Se + 100 mg VE. The highest of glucose content was obtained in supplemented treatment with 0.5 mg Nano-Se + 100 mg VE. For cholesterol and triglyceride, the highest values were reported in fish fed with treatments containing 0.5 mg mineral Se + 150 mg VE + 20 mg CoQ10 and 0.5 mg Nano-Se + 100 mg VE, respectively. Similarly, the highest values ​​of HDL and VLDL indices were observed fish fed with 0.5 mg Nano-Se + 100 mg VE. In contrast, the control treatment showed the highest LDL value. The results of this study revealed that supplemented diet with Nano-Se at level of 0.5 mg and VE at level of 100 mg can be effective in improving the growth and blood biochemical indices of rainbow trout.

The effects of cadmium and calcium carbonate concentration were investigated at different temperatures on the morphological characteristics of freshwater crabs Potamon persicum (Pretzmann, 1962) using traditional morphometrics methods, 60 samples of random sampling in the west of Mazandaran and Karaj Rivers in the Central Alborz, Iran. The crabs were exposed to zero cadmium and 205 mg/l calcium carbonate as a control treatment and 4.5 and 9 mg/l cadmium concentrations and 302.5 and 400 mg/l carbonate calcium hardnesses at 18, 24, and 30 ° C temperatures for 6-weeks as experimental treatments. We studied the effects of water physicochemical parameters on serum biochemical properties in the hemolymph of the crabs including ALT and ALP enzymes and morphometric ratios between CW/CHL, CW/CHD, and CW/MBDWt in males and CW/MBDWt in both males and females. The results showed that increasing the two factors of temperature and cadmium alone had a significant positive effect on increasing the amount of ALT hemolymph enzyme in the studied crabs (P <0.05).In this study, the interaction of cadmium and calcium carbonate on the serum level of ALT enzyme hemolymph in crabs was significant and the negative effects of cadmium on ALT enzyme decreased with increasing calcium carbonate hardness (P<0.01). However, studied physicochemical factors had no significant effects on the serum level of ALP (P> 0.05). However, the interaction of calcium carbonate with cadmium on the serum level of ALP enzyme was significant and with increasing both variables, the amount of ALP enzyme in crab hemolymph increased (P <0.05). The present study also showed that the interaction of all three variables on CW/CHD and CW/CHL ratio of male crabs was not significant (P> 0.05), but the interaction of all three variables on CW/MBDWt of male and female crabs was significant at a 95% confidence level (P <0.05). According to the values ​​obtained in finding the optimal points of the studied variables on the maximum morphological ratios and the optimal level of ALP and ALT enzymes, recommend using high rates of desirability (80-95%) with temperature 18-20°C, Calcium carbonate hardness about 240-311 mg/l, And the absence of cadmium in the aqueous medium.

For several years, microalgae have been known to promise sustainable and cost-effectiveFor several years, microalgae have been known to promise sustainable and cost-effective production of food, fuel and chemicals. Many algal species produce lipids as triacylglycerols with fatty acid compounds similar to vegetable oils (TAGs). Therefore, microalgae are a good choice for the sustainable production of natural edible oils. In this study, the effect of mixotroph culture and nitrogen shock on dry weight, fat content and profile of fatty acids of Chlorella vulgaris were investigated. In this study, BBM culture medium used at temperature 25°C to grow microalgae. Cell count indices, nitrate, pH, dry weight, fat weight, fat percentage and profile of fatty acids were measured. The results showed that mixotroph culture and nitrogen shock are significant on biomass and fat content (p <0.05). Based on the results, it was determined that for dry weight, the glucose mixotroph with 100% nitrate in BBM medium 916.66 ± 35.11 mg/l, for the amount of fat in mixotrophic culture, glucose with 25% nitrate in BBM culture medium 49.61 ± 0.36 mg/l and for linolenic acid (omega 3) autotrophic culture with 100% nitrate 19.72 ± 0.1% had the highest production values. In conclusion, nitrogen shock reduces cell biomass and increases microalgae oil, as well as decreases omega-3 fatty acids.