Recent Submissions

  • The effects of replacing fish meal with barley protein concentrate on digestive enzyme activity and hepatic enzymes of Caspian salmon (Salmo trutta caspius)

    Zaretabar, A.; Oraji, H.; Yegane, S.; Keramat, A. (2020)
    The effects of replacing fish meal with barley protein concentrate (BPC) on digestive enzyme activity and hepatic enzymes of Caspian salmon (Salmo trutta caspius) in a 8 week study with a weight mean 16.53±1.1g with completely a randomized design with 5 treatments and 3 replications was used. Experimental diets consisted of control diet (without barley protein concentrate) and four diets containing levels of 25, 50, 75, 100% barley protein concentrate. At the end of the experiment, ALP, AST and ALT levels was significantly different in different experimental treatments (p <0.05). However, there was no significant difference in LDH between different treatments (p >0.05).In fish fed with experimental diets pepsin enzyme activity in experimental diets up to 75% replacement with control treatment there was no significant difference (p <0.05). The activity of Chymotrypsin and Aminopeptidase in different treatments showed a significant difference compared to control (p >0.05). In fish fed with experimental diets up to 50% replacement in trypsin and alkaline phosphatase activity compared to control treatment was no significant difference (p <0.05). The activity of amylase and lipase enzymes showed a significant difference between treatments with different levels of barley concentrate (p <0.05). digestive enzymes decreased at higher replacement levels, but in the middle levels of replacement, there was less effectsin pancreatic enzymes. It can, therefore, be concluded that BPC levels up to 50% of the diet are tolerable for the Caspian salmon, but levels exceeding this limit will probably result in an increase in anti-nutrients,­ a decrease in nutrient uptake, low diet palatability, and adverse effects on fish growth.
  • Biological aspects and growth Clupeonella cultriventris caspia on the coast of Iran in the last decade

    Janbaz, A.; Fazli, H.; Afraei Bandpei, M.A.; Razeghian, G.; Bagherzadeh, F.; Khedmati, K. (2020)
    The changes in biological structure and growth common kilka were investigation during 2008-2017 in the Iranian waters of the Caspian Sea. Kilka fishing ships discharged theirs catch in three ports : Babolsar, Amirabad and Anzali. The sample based on the length of 5 mm were classified class. Fork length ranged from 52.5 to 142.5 mm and mean (±SD) 101.9±10.5 and fish fork length 92.5-112.5 mm of the population have been dominant (81%)(n= 49759). The slight fluctuations in the average length with values ​​between 100 and 105 mm. During this period, fish of +3 and +4 years old have been dominant with frequency of 80-70%. The stability length and weighted mean of generation growth rate was indicative of relative stability and the average age of common kilka stability, the stability of the population are descendants entered and confirmed. The results showed that in the year 2008 the frequency of young fish 1-2 years was 15.2% of the catch, but gradually in the following years, the abundance of these fish in the hake decreased, so that in 2017, only 10% of the catches were allocated. Reducing overfishing and pressure on young fish stocks is an opportunity to rehabilitate stocks of this species.
  • Evaluation of SEYMAREH Dam Reservoir Water Quality by Bacterial Indices and relationship-with some Water physical and chemical parameters

    Houshmand, H.; Ahangarzadeh, M.; Dehghan Madiseh, S.; Seyed Mortezaei, S. (2020)
    Reservoirs are artificial lakes that have been created by humans for specific purposes. Water reservoirs has different uses which the most important are: municipal water supply, agricultural irrigation, aquaculture, power generation and etc. According to increasing of water demand the accurate study of water resources, determination of their pollutants, prevention, pollution control and optimal use of available water resources are required. Saymareh Dam is located about 40 km northwest of DARREH SHAHR in ILAM province. This dam was constructed with the aim of producing electric power, controlling and regulating of river floods. The aim of this study was to survey on the bacterial contamination of Seymareh Reservoir and its relationship to some water physical and chemical factors. According to the geographical and hydrological status of the reservoir, five stations (one station near the water entrance to the lake, 3 stations at the beginning of the lake, middle and near the crown, and one station after the reservoir) were sampled 8 months in 3 seasons of year for bacteriological, physical and chemical evaluation. Water quality standards for microbiological sampling were used. Then microbial tests including total bacterial count, total coliform count, fecal coliform and fecal streptococcus count were performed. In each station simultaneous measurements of some physical and chemical parameters of water (temperature, dissolved oxygen and pH) were also evaluated. The results showed that the highest total bacteria counted during sampling at station 5 (after reservoir) and the lowest rate at station 4 (before the reservoir's crown). Also the average of total and fecal coliform was the highest at station 5 in all sampling seasons and the lowest in station 2. The stations grouping in this three indices showed that the entrance and outlet stations of the reservoir (1 and 5) are in the same group and the stations located on the reservoir (2, 3 and 4) are in the other group that showed a significant difference (p<0.05).In the Pearson test, correlation between water temperature and pH changes with the number of total bacteria and fecal coliform was positive and with the total coliform was negative, while dissolved oxygen showed a negative correlation with three bacterial indexes. In comparison to the bacterial parameters with available aquaculture standards, the water of this reservoir is suitable for fish production in all seasons.
  • Effects of enriched food with selenium nanoparticles on breeding efficiency of female rainbow trout (Oncorhynchus mykiss)

    Falahat Naserabad, E.; Ziaei Nejad, S.; Ghaedi, A.; Seyedi, M.; Moradian, S.H. (2020)
    This research investigated the influence of selenium nanoparticles (SeNPs) on the reproductive performance of female rainbow trout (mykiss Oncorhynchus) broodstocks. A total of 120 female broodstock were selected from breeders of the Shahid Motahary Coldwater Fishes Genetic and Breeding Research Center. After adaptation, fish were divided into four treatments in three replicates. Fish were fed diets containing 0 (control) 0.5, 1 and 2 mg SeNPs per kg of diet for 60 days. Eggs quality parameters such as fecundity, fertilization rate, eyed egg rate, hatching, etc. were evaluated. The highest fertilization rate was observed in fish fed with 2 mg selenium (99.30%), which had a significant difference with control groups (p< 0.05) but did not show any significant difference (p>0.05) with fish fed 0.5 mg and 1 mg SeNPs. Broodstocks fed with 2 mg SeNPs had the highest absolute fecundity, which had a significant difference with groups fed 1 mg SeNPs (p <0.05), but did not show significant difference with other two treatments (p >0.05). ) The highest and the lowest relative fecundity were seen in group fed 2 mg SeNPs and 1 mg SeNPs, respectively. However, there was no significant difference in relative fecundity between treatments (p >0.05). The highest egg diameter was in fish fed 0.5 mg SeNPs. Egg diameter in the control group, fish fed 2 and 1 mg SeNPs, were 5.39, 5.39 and 5.40 mm, respectively). There was no significant difference for egg diameters among gruops (p> 0.05). The highest and the lowest mean total egg weight were in group fed 0.5 mg SeNPs and 1 mg SeNPs, respectively, and no significant differences were observed between treatments (P >0.05). The highest percentage of hatching was observed in groups fed 2 mg SeNPs, which had a significant difference with other treatments (p <0.05). The highest survival rate was observed in groups fed 2 mg SeNPs too, which showed no significant difference with other treatments (p >0.05). Increase in the survival rate associated with an increase in the concentration of SeNPs. In general, inclusion of SeNPs in diet, improve the quality and quantity of eggs and reproductive function (fertilization, eyed rate and hatching) in rainbow trout breeders.
  • Evaluation the effects of temperature, magnesium and iron on Arthrospira plantensis growth and biomass production

    Jarayan, R.; Fatemi, M.R.; Mashinchian Moradi, A. (2020)
    This study was conducted to investigate the effects of temperature (24 and 30 ˚C), magnesium and iron removal on Arthrospira plantensis growth and biomass in vitro For this purpose two culture media have been used: Zarrouk and Jourdan culture medium. Removal of magnesium and iron were performed in six treatments and two controls with three replications. Temperature experiments were performed in two treatments with three replications for two mentioned media. Optical density of samples was measured daily by a spectrophotometer at 560 nm. In addition, biomass was measured in g/L at two stages (in 7 and 14 days). pH was measured daily. The results showed that in Zarrouk culture medium (control), mg free treatment and mg-fe free treatment have the highest biomass in day 7 (0.88 g/L). In day 7, among all treatments (mg free, fe free, mg-fe free), only mg free treatment showed statistically significant with standard culture medium (Zarrouk), (p<0.05). In day 14, the mg free treatment showed the highest biomass (0.95 g/L), but there was not significant difference between treatments (mg free, fe free, mg-fe free) and standard culture medium (Zarrouk), (p<0.05). In Jourdan culture medium, control and fe free treatment have the highest biomass (0.7 g/L) in day 7; and fe free treatment has the highest biomass (1.27 g/L) in day 14; but there was not significant difference between treatments (mg free, fe free, mg-fe free) and standard culture medium (Jourdan), (p<0.05). Regarding to temperature effects, in Zarrouk and Jourdan media, the highest growth observed at 24˚C and 30˚C, with 2.74 and 2.14 g/L respectively. There was significant difference between treatments (24 and 30˚C), (p<0.05). results indicated A. plantensis can be cultivated in large scale by removing magnesium and iron from medium by this way, we could reduce the culturing cost of A. plantensis.
  • Evaluation of the effect of different levels of Pontogammarus maeoticus extract on growth indices, carcass composition and mucosal safety of Rutilus kutum, Kamenskii, 1901

    Rufchaei, R.; Nasri Tajen, M.; Salavatian, M.; Jamili, Shahla; Hematkar, F.; Ghorbani, S. (2020)
    In this study, the effect of diets containing different levels of Pontogammarus maeoticus extract as natural nutrient attractant was investigated on growth indices, chemical composition and mucosal Immunity of Rutilus kutum. For this purpose, fish with an average weight of 0.35±0.067 were stored in 100L fiberglass tanks containing 30 liters water with a density of 20 fish per tank for eight weeks. To perform this study, Gammaridae extracts were mixed with distilled water in three concentrations: 1:25 (25%), 1:50 (50%), 1:75 (75%) and two percent of each dilution was added to manual meals before each feeding. This experiment was performed as four triplicated treatments. Larvae were fed four times a day. At the end of the culture, growth indices such as: mean body weight gain, specific growth factor, food conversion ratio, survival, chemical analysis of carcasses and some mucosal immune parameters including; lysozyme, immunoglobulin, alkaline phosphatase and protease were studied. The results showed that although growth factor and carcass analysis were improved in all treatments (25%), this increase was not significant compared to the control (p>0.05). All Mucus immune factors significantly increased in all treatments compare to control (p<0.05). The result of this study showed that the Gammaridae extract had no significant effect on the improvement of growth performance, but increased the immunity of Rutilus frisii in culture conditions.
  • Study of behavior, priorities and barriers of shrimp consumers in Iran

    Reyhanipoul, S.; Alishahi, A.; Adeli, A.; Nargesian, A.; Ojaq, S.M. (2020)
    Planning to increase the per capita consumption of shrimp in the country, like any other food, will not be possible without an examination of consumer's behavior and the recognition of their needs, interest and tastes. The purpose of this study was also, to assess the priorities of shrimp consumers and their barriers to consumption in the country. The statistical population of the study was the whole country that was selected by random sampling of 10 cities and completed 1000 questionnaires corresponding to the population of the mentioned cities. Questionnaire data were transferred to the SPSS 20 software and ranking of desired factors were determined by Friedman test. The results showed that the three first priorities of consumers were quality, packaging and experimental records. Other priorities were positive and negative beliefs, supplying and processing model, price, availability, convenience of cooking, consumer income, and time-consuming, respectively. In term of the quality, packaging, positive and negative beliefs and processing model, the first priority of consumption society was smell, brands name, tissue contamination and fried shrimp (packaging), respectively. The study of barriers to consumption of this product in the country showed that the prices (expensive) of shrimp, its smell, and disproportion of shrimp prices with people's incomes were the first three barriers to buying and consuming shrimp in Iran, respectively. In this research, per capita consumption was calculated 98.5 and 487 grams for the statistical population and consumption society respectively. According to the results, in order to increase the per capita consumption, this industry's managers should concentrate their activities on quality and packaging indicators and final price of product.
  • The effect of media type on ammonia levels and growth performance of guppy (Poecilia reticulata) in recirculating systems

    Mohammadrezaei, D. (2020)
    Removing ammonia in recirculating systems is necessary to increase efficiency and reducing ammonia toxicity. So, the select appropriate type of media to reduce is very important. In this study, four different materials (bio-Ball, wood flake, seashell, and natural pumice) as media and guppies as fish sample were used for 40 days. The results showed that the level of ammonia decreased in all media, but this reducing was higher in wood flake than other treatments. Also, the growth indices showed that the fish in the aquarium with wood flake and seashell had a better performance than other media. Accordingly, it can be concluded that due to the better performance of wood flake to reduce ammonia and make more optimal environmental conditions than other media, it can be an appropriate media for bio-filters.
  • Effects of using different C/N ratios in biofloc system on growth performance, feeding and water quality indices of common carp (Cyprinus carpio) culture

    Minabi, K.; Sourinejad, I.; Alizadeh, M.; Rajabzadeh, E. (2020)
    Effects of using various ratios of C:N in biofloc system on growth performance, feeding indices and culture water quality of common carp with mean weight of 14.17±0.36 g were investigated during 90 days in experimental treatments including control (no extra carbon source) and four treatments with different C:N ratios of 11, 15, 19 and 23 each with 3 replicates. The increase in C:N ratio had a significant effect on growth and feeding indices of cultured common carp in treatments (p<0.05). The highest final weight and weight gain, the lowest FCR and the highest SGR were observed in C:N ratio of 19. No significant difference was observed in survival rate among different treatments indicating that the culture condition was suitable for common carp in this biofloc system. Hepatosomatic and visceral indices did not show significant differences between treatments with different C:N ratios (p> 0.05). Water quality indices including DO, pH, TDS, EC, TSS, FV, TAN, nirtite and nitrate showed significant differences in biofloc system with different C:N ratios (p<0.05). The mean values of FV and TSS in biofloc system increased with increasing C:N ratio. The variation pattern of the mean TAN and nitrite were the same as each other and reverse to the trend of TSS and FV showed a decreasing trend with increasing C:N ratio. These trends indicate the significant removal of nitrogenous compounds by bioflocs. In conclusion, using C:N ratio of 19 with molasses as carbon source in biofloc system could be recommended to improve water quality, growth and feeding performance of cultured common carp.
  • Growth performance, body chemical compsitions and digestive enzymes in grey mullet, Mugil cephalus Linnaeus 1758, fed with different levels of Saccharomyces cerevisiae yeast

    Akbary, P. (2020)
    Probiotics, as a live microbial dietary supplement, play an important role in the growth and activity of the host digestive enzymes by balancing the gut microbial population.The present study was conducted with 4 treatments and 3 replications including diets containing 1×106, 3×106 and 5 ×106 (cell/ g feed) and control (basal diet without yeast) to evaluate the effect of different levels of dietary supplementation of Saccharomyces cerevisiae on growth performance, body biochemical composition and digestive enzymes activities of grey mullet, Mugil cephalus. The fish (5.56±0.65 g) were randomly allocated into 12 fiberglass tanks at a density of 20 individuals per tank with three replicates for each treatment and fed with the experimental diets for 60 days. The results indicated that the diet at 5×106 yeast cells/ g( significantly improved weight gain (240.36±13.57%), final weight (919.28±1.55), protein efficiency (10.01± 0.56%) and survival (94.40±13.57%) compared to the control and treatment 2 (p<0.05). Also, the highest activity of amylase (199.50±17.70 U/mg protein) and protease (362.50±13.52 U/mg protein) were observed in 5×106 yeast cells/ g diet (P<0.05). This study shows that the use of S. cerevisiae 3×106 and 5 ×106 yeast cell/ g feed can have positive effects on growth performance, feed utilization, body chemical composition and digestive enzymes activities of M. cephalus.
  • Immunohistochemical and ultrastructural study of the effect of different salinities on gill chloride cells of Cyprinus Carpio

    Basir, Z.; Peyghan, R. (2020)
    120 specimens of common carp were treated in salt water with 4ppt, 8ppt, 12ppt treatments and freshwater with three replications for 2 weeks. For histomorphology study in the end of the period thickness of 4μ to 6μ were prepared. Also samples were collected for immunohistochemical and ultrastructural studies. Results showed that at the filament position, the highest and lowest number of chloride cells belonged to 8 ppt salinity and control treatment, respectively. Also at this position, the largest size of the cells belonged to the salinity of 12 ppt and the smallest size belonging to 4 ppt. At the lamellar site, the highest number of chloride cells belonged to 4 ppt salinity and the lowest number belonged to the control treatment without changing in the size. In immunohistochemical studies for Na⁺/K⁺-ATPase localization, it was found that chloride cells were high in filament epithelium and few in the lamellar epithelium in different salinities. These cells were present with intense immunofluorescence in the apex, base, and between inter lamellar filament. According to the electron microscopy studies, the membrane of the chloride cells of the gill of common carp showed that different apical morphologies as the deep hole, shallow basin and wavy convex. In general, range of tolerance and adaptation of common carp is high to salinity changes due to rapid changes in chloride cells in the direction of entering and leaving water and electrolytes. So that, this species was able to adapt to the changes in environmental different salinity and to survive.
  • Survey of some metal elements (Cu, Zn, Ni, Pb) accumulation in muscle, liver, kidney and gill of Schizocypris altidorsalis in Chahnimeh reservoirs of Sistan

    Mirnia, N.; Mirdar Harijani, J.; Gharaei, A.; Rigi, M. (2020)
    This research aims to study is the pattern of metal elements accumulation including copper, zinc, nickel and lead in the muscle, gills, liver and kidney of Schizocypris altidorsalis, in Chahnimeh reservoirs of Sistan. For this purpose, 40 samples were collected randomly from the population in winter and spring (20 samples each season). In the next phase of the research, muscle, gill, liver and kidney tissues of the samples were cut out for further study. Then, the concentrations of heavy metals were measured using atomic absorption. The samples were already prepared and treated by nitric acid of high concentration. The results of the study showed that concentrations of copper, zinc and nickel in muscle tissue in winter season were 43.01±1.39, 143.08±0.63, 8.01±0.53 and 1.13±0.18 µgr.gr-1 dry weight, respectively. Also these results in spring were 42.90±1.50, 141.04±3.02, 7.07±1.56 and 4.32±0.22 µgr.gr-1 dry weight respectively. Totally, the highest amount of copper and zinc elements in the liver tissue and lead and nickel elements were measured in gill tissue. Finally, the results of the current research showed that the concentrations of these metals in muscle tissues are higher than limits set by FAO and WHO standards. But, the concentration of nickel was lower than FDA standard.
  • Effect of probiotic Lactococcus lactis (PTCC 1403) and chitin on blood and serum biochemical parameters and intestine bacteria of Common carp (Cyprinus carpio)

    Barghaman, H.; Yeganeh, S.; Keramat Amirkolaie, A. (2020)
    The aim of the current study was to evaluate the effect of dietary Lactococcus lactis subsp. lactis and chitin on blood and serum biochemical parameters and intestine bacteria of common carp. To do the experiment, 360 juvenile carp with mean initial weight of 12±1.5 g were randomly distributed in the fiberglass tanks designed based on different levels of chitin 0, 1 and 2% and probiotic 0 and 2% (1 ×107CFU/g) in diet and the experiment lasted for eight weeks. The experimental treatments were including control (treatment 1), probiotic 2% (treatment 2), chitin 1% (treatment 3), chitin 2% (treatment 4), probiotic 2% + chitin 1% (treatment 5) and probiotic 2% + chitin 1% (treatment 6). On the end of the experiment, blood parameters including red blood cell (RBC), Mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), mean corpuscular hemoglobin concentration (MCHC), hemoglobin (Hb), hematocrit (HCT), white blood cell (WBC), lymphocyte, eosinophil and monocyte, serum biochemical parameters including total protein, albumin, glucose, cholesterol, triglyceride and intestinal bacterial colony were determined. The results showed that RBC, MCV, MCH, MCHC, Hb, HCT, thrombocyte, monocyte had no significant difference among treatments (p>0.05), But, maximum level of WBC in treatments 5 and 3 (18.03±1.66, 16.86±1.49 103 mm3, respectively), lymphocyte in treatments 5 and 2 (70.40±4.58, 65.00±2.65, respectively) and eosinophil in treatments 3 and 6 (2.67±1.16, 1.67±0.58, respectively) were observed. Biochemical parameters showed no significant difference among experimental treatments and control, but, there were significant difference among the diets containing probiotic and chitin or/and a mixture of probiotic and chitin (p<0.05). The intestinal bacterial colony in all treatments except treatment 6 was more than the control (p<0.05). The maximum bacterial colony count was observed in treatment 4 (653.33±25.17 CFU/g). In conclusion, it seems the addition 2% probiotic, 1% chitin and a mixture of them can improve white blood cells and intestinal bacterial colony in common carp.
  • Effect of dietary enrichment of Padina algae (Padina astraulis Hauck) on serum immune indices of Common carp Cyprinus carpio in exposure to zinc oxide nanoparticle

    Ghani, S.; Maddah, S.; Hedayati, A.; Kakavand, F.; Iri, A.; Sanchooli, H.; Sheikhveisi, R. (2020)
    The use of immune stimulants such as algae has a key role in enhancing of immunity. On the other hand, the presence of nanoparticles affects the physiological status of fish and reduces their immune function. Therefore, the purpose of this study was to investigate the effect of enrichment of diet with algae on carp serum immune parameters in exposure to zinc oxide. 250 common carp were divided in four groups for 42 days, algae-free (treatment 1, control), food containing 0.5% algae (treatment 2), food containing 1% algae (treatment 3) and food containing 2% algae (treatment 4), then 50% of acute concentration of zinc oxide nanoparticles (1.5 mg/l) was added to each of the groups over a period of fourteen days. The results of this study showed that in general, experimental treatments had a significant effect on serum protein, immunoglobulin and serum albumin levels (P<0.05), but there was no significant effect on serum glucose (P>0.05). Also, experimental treatments had a significant effect on ASA, ALP and ALT levels (P<0.05). The significantly increased rate of these indices was due to treatments fed with algae. Also, these indices increased significantly in treatment of zinc oxide and also in zinc with algae group. Experimental treatments did not had a significant effect on blood glucose level (P>0.05). It can be concluded that Padina algae may partially improve the reducing effect of nano-oxide on serum total protein and immunoglobulin levels, which requires further research in this regard.
  • Updated checklist and geographical distribution of fishes in Kohgiluyeh and Boyer-Ahmad Province

    Fatemi, Y.; Amoei, M.; Mousavi Sabet, S.H. (2020)
    The present study aimed to investigate the biodiversity and distribution of fishes in Kohgiluyeh and Boyer-Ahmad Province, and providing an updated checklist of fishes in this province. Samplings were done in the Bashar, Zohreh, Semmeh and Maroun rivers drainages troughout this province during 2017-2018. Overal, 27 specices belonging to 18 genera and 4 families were identified, including ten endemic, fourteen native and three exotic species. From these, 9 more species are listed for the province comparing the previous checklist. Also, ichthyodiversity hotspots in the province were introduced, ichthyodiversity threats were investigated and some protection solutions are suggested.
  • Extraction and purification of Trypsin from intestine of Caspian kutum (Rutilus frisii Kutum) and Calculation of its Kinetic parameters and Half Life

    Hasebi, Z.; Motamedzadegan, A.; Madani, R.; Zamani, A. (2020)
    In recent decades, recovery and identification of digestive enzymes from fish has attracted much attention and new applications for these enzymes have been defined in some industries, such as the food and detergent industries. One of these recovered enzymes is Trypsin, which in this study was extracted and purified from the intestine of Caspian kutum using a three-step extraction method with 50 mM Tris-HCl buffer (containing 10 mM CaCl2 pH 7.5), 60% ammonium sulfate precipitation and Sephadex G-75 gel chromatography. The Result was an enzyme with 52% yield and a purity of 25.78-fold. The kinetic parameters of Vmax and Km for BAPNA substrate were calculated using the Michaelis-Menten equation and were 2.9958 µmol/mg.min and 0.5350 mM respectively and Kcat was 6.2568 S-1. The kutum Trypsin’s half-life was also calculated as 58.72 min for BAPNA substrate using the conversion of the enzyme activity graph (in minutes) to natural logarithmic graph and determining its slope. The results showed that it is easy and economical to extract and purify Trypsin from intestine of Caspian kutum and it is kinetically more effective than commercial Trypsin. It is suitable for use in the food industries, fish processing industry, culture media production as well as application in biotechnology research.
  • Antifouling activity of sea cucumber (Stichopus herrmanni) extracts in laboratory and its performance in resin epoxy coats in the sea environment

    Darya, M.; Sajjadi, M.; Yousefzadi, M.; Sourinejad, I.; Zarei, M. (2020)
    Development of natural and environmentally friendly antifouling agents is a suitable alternative to solve the global marine fouling problem. In the current study, antibacterial, anti-micro algal, anti-barnacle and antifouling activity of non-polar, semi-polar and polar extracts from three parts of the sea cucumber, Stichopus herrmanni, body (i.e. body wall, digestive tract and respiratory tree) were studied. The inhibitory activity assay of n-hexan, ethyl acetate and methanol extracts were evaluated against five bacterial strains, two microalgae species and barnacle larvae. In order to investigate the antifouling performance, the extracts were added to a resin epoxy coats and exposed in the sea water for the duration of three months. Based on Results, the ethyl acetate extract of the body wall with the lowest MIC against S. aureus (0.500 mg/ml) and I. galbana (0.125 mg/ml), and the lowest LC50 against barnacle larvae (0.061 mg/ml), showed the best inhibitory activity. After three months treatment, the coated panels containing 4% extract of ethyl acetate from body wall had the lowest final weight (189.67 ± 5.51 g) and lowest fouling cover percentage (74.76%) among all the panels (P<0.05). Regarding the high antifouling activity of ethyl acetate extract from the body wall of the sea cucumber S. herrmanni, it is recommended as a potential natural alternative for the antifouling coats.
  • Effect of different dietary carbohydrate source on growth performance, body indices and activity of digestive enzyme (amylase) of Pangasiandon hypopthalmus

    Asemani, M.; Hafezieh, M.; Sepahdari, A.; Dadgar, S. (2020)
    In the present study, the effect of seven dietary carbohydrate sources on growth performance, feed utilization and amylase activity of Pangasiandon hypopthalmus was evaluated for 12 weeks. Fish subjected to diets containing raw dextrin and potato starch showed a significantly (p< 0.05) higher growth rate than those fish consuming other experimental diets, except wheat starch diet. Furthermore, fish fed with wheat and corn starch showed significantly higher (p<0.05) Interaperitoneal fat value than that of fish fed with potato, Alfa and waxy maize starch. Moreover, fish fed with wheat starch had significantly higher (p<0.05) amylase activity than that of those subjected to other experimental diets, except corn and waxy maize diets. Overall, this study showed that the raw forms of dextrin starch and potato were suitable dietary carbohydrate sources for further scientific studies on the carbohydrate utilisation of P. hypophthalmus.
  • Study on risk factors in rainbow trout breeding and rearing farms based on water environmental parameters in the Haraz River

    Nasrollahzadeh Saravi, H.; Ghiasi, M.; Safari, R.; Makhlough, A.; Nasrollahtabar, A.; Mohammadzadeh, V.; Monemi, A. (2020)
    This study was carried out to determine the water environmental parameters as risk factors for rainbow trout breeding and rearing farms in the Haraz River. 84 water samples were collected at 6 stations during seven months in 2017-2018. Water samples were analyzed by standard titration and spectrophotometry. Results showed that the range of water temperature (4.0-17.0◦C), weather temperature (5.0-28.0◦C), dissolved oxygen (7.36-14.24 mg/l), BOD5 (0.20-20.80 mg/l), COD (3.50-41.40 mg/l), electro-conductivity (345-650 µS/cm), turbidity (2-81 NTU), TSS (0.01-0.72 g/l), pH (6.98-8.15), TP/P (0.01-0.15 mg/l), PO43- (0.01-0.20 mg/l), NH4+ (0.02-0.31 mg/l), NH3 (0.14-4.36 µg/l), NO2- (0.01-0.21 mg/l), fecal coliform (9-30000 CFU/100ml) and water quality index (48.5-98.5) were changed. The results of the stepwise regression analysis indicated that the risk factors of water quality in the Haraz River were fecal coliform, phosphate, turbidity, and BOD5 parameters, and fecal coliform had a higher coefficient factor (beta coefficient) than other parameters (p<0.05). As a result, according to the average water index of stations (less than 55), water of the Haraz River is contaminated and critical to breeding and rearing trout, but it has acceptable microbial count for fish farming and wildlife. In addition to seasonal conditions such as environmental conditions and rainfall, the way of pound managing has been effective in maintaining water quality.

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