نشریه علوم آبزی پروری ایران
سال هفتم شماره 2 (پاییز و زمستان 1398)

This study was carried out to evaluate the effects of different levels of dietary curcumin on growth performance and biochemical parameters of Oscar (Astronotus ocellatus). A total number of 150 fish with initial average weight of 5.19±0.01 g and average total length of 6.32±0.06 cm were randomly distributed into 5 treatments. Fish were fed with diet containing different levels of curcumin, including control group without curcumin (C0), 5 (C5), 10 (C10), 15 (C15) and 20 (C20) g curcumin kg-1 diet for 56 days. Growth indices were measured every 2 weeks interval. Significant differences were observed in the fourth week. The results showed that highest final body weight, final length, weight gain, body weight gain, daily growth rate, specific growth rate and the lowest FCR were observed in C5 treatment compared to those fed the control diet (P<0.05). There were no significant differences in condition factor between control and other treatments (P>0.05). The lowest plasma glucose and cholesterol levels were measured in C15 and the lowest triglyceride level was found in C5 treatment (P<0.05). There was no mortality during the trial. The results showed that using curcumin can cause effective results in the growth performance and some biochemical parameters in Oscar fish.

Drying due to shelf-life extend, easy transportation, and increase in lipids extraction and other bioactive compounds yield is a vital step in harvesting of algae biomass. In the present study, the effect of four drying methods, including sun drying, oven drying, freeze drying and spray drying methods on some nutritional composition and pigments of a marine microalga Isochrysis galbana was investigated. Proximate compositions (moisture, crude protein, crude lipid, ash) and pigments (chlorophylls and carotenoid) of the dried algae were determined. The results indicated that dietary protein and lipid were the most abundant components of the microalgae. No significant differences was found in the content of Chl-a among all dried samples (P>0.05). Freeze-dried samples had the highest content of total protein (62.33±0.56%), Chl-b (0.167±0.02µg/ml) and carotenoid (0. 153±0.01µg/ml) compared to others (P<0.05). However, spray-dried and sun-dried algae had the highest values of crude lipid (15.41±0.25%) and ash (17.51±0.14%), respectively (P<0.05). It can be concluded that some of the nutritional composition of microalga I. galbana is significantly affected by different drying methods and freeze drying can be suggested as an efficient method to maintain the algae with relatively lower negative effect on the nutritional composition in the dried condition.

This experiment was conducted to evaluate some of the hematological (RBC, WBC, MCV, MCH, MCHC, Hb, PCV) and serum biochemical factors (TSP, GLU, COR, AST,ALT and ALP) of 2 to 3 year’s old Great Sturgeon during the yearlong period (autumn 2015 to summer 2016) at the Sturgeon Institute, Shahid Marjani in different seasons. For this purpose, after the seasonal blood sampling a total of 15 great sturgeon specimens were apparentlyhealthy after bleeding in the caudal vein hematological and serum biochemical indices was determined by standard protocols. Based on the results, seasonal variations were observed in WBCS, PCV, Hb, MCV, MCH, MCHC values, activity of AST, ALP enzymes and glucose and cortisol levels (P<0.05). But, there were no any significant differences between RBCs number’s, TSP levels and ALT values (P>0.05). Based on the results and according to the stable of all environmental conditions, except for temperature, couldbe claimed that temperature changes can be very important as a key factor in determining of hematological and biochemical indices of Huso huso in the different season that were complementary to the changes in water quality parameters indicating that environmental changes affects the blood chemistry of Huso huso. Overally, the hematological and biochemical values of the present study can be used as reference for monitoring of physiological and health status of Huso huso from Sturgeon Institute, Shahid Marjani and other center of the fishing and processing sturgeon fishes.

In this research, recreational value of fish farming activity has been investigated using a conditional valuation method in one of the villages of Qaemshahr city. The objectives of this study are to estimate the recreational value of this activity and to examine the effects of socioeconomic variables on the willingness to pay visitors. To measure the willingness to pay, the Logit model is used and based on the maximum right-of-way method, the characteristics of this model, such as the final effect and weight traction, were estimated. The final effects of the change are also calculated in each of the variables included in the model using the final effect factor. The data used in this study was the distribution of 110 questionnaires whose validity and reliability were confirmed. The results showed that the variables such as age, educational level, number of household members, people's income and household income of the visitors had a significant effect on the willingness to pay. Also, the study showed that the maximum willingness to pay for fish is 1191.2 Taman. Maximum willingness to pay is indicative of the potential capacity of these two activities in the field of agro-tourism, which requires serious attention.

Sea cucumber is one of the most important ecological and economic species in Persian Gulf and Oman Sea. Sequencing was used to study the genetic diversity and population structure of Holothuria leucospilota in the north of the Persian Gulf and Oman Sea. For this purpose, 58 samples were captured from Bushehr, Bandar abbas and Chabahar. DNA from muscle tissue was extracted using Ammonium Acetate method. Polymerase Chain Reaction (PCR) was conducted on the targeted DNAs and DNA sequencing was carried out. The mean of haplotype diversity was high (0.78), 0.81 Chabahar, 0.8 Bandar abbas and 0.74 Bushehr. The lowest genetic differences were observed between Bandar abbas and Bushehr and the highest between Chabahar and Bushehr. The highest genetic distance was observed between Chabahar and Bushehr (0.08) and the lowest betwee Chabahar and Bushehr (0.03). The esult showed different population of H. leucospilota which should be considered in management of this economically important species.

Despite a high levels of global fishing and the related processing industrie, little efforts have been made to recycle waste products of these factories. If these biological compounds be properly processed, they can reduce the environmental pollution resulted due to such a wastes, and their valuable protein content can be recycled. Therefore the present study was conducted to obtain an economically valuable enzyme i.e. acinidine enzyme from Kiwi fruit. In addition, Rainbow trout waste was considered as a potential source of hydrolysable protein. Based on the results, the specific enzyme activity of the 1 kg of kiwi fruit was estimated as 36.8 mg/u. As a result of protein source hydrolysis by applying the actinidine enzyme, the rate of nitrogen recovery and the degree of rainbow trout hydrolysis were recorded as 31.77 and 21%, respectively. Furtheremoe, the results showed that the percentage of crude protein and ash content increas, however, the crude fat percentage decreases. Based on the results of the amino acid profile analysis, these hydrolysates can be provide the proteins of human and Rainbow trout. The results indicated that the actinidine enzyme can be used as a protease enzyme to extract protein from Rainbow trout wastes in the food industry.

The use of macro algaes in various industries has led researchers to a great deal of enthusiasm for spacious studies on anti-fungal, anti-bacterial, anti-viral, and anti-cancer properties. The present study was accomplished to determine the anti-bacterial and anti-oxidant activity of alginate and fucoidan extracted from brown algae (S. boveanum) collected from the Persian Gulf coast. In this study, the antioxidant activity, iron chelating agent, DPPH and superoxide free radical inhibitory activity showed that alginates and fucoidan extracted from these algae showed high antioxidant activity. Anti-bacterial activity against seven pathogenic and non-pathogenic bacterial species showed that, Y. ruckeri was resistant to alginate and fucoidan. According to the results of this study, brown algae extract from S. boveanum can be used as anti-bacterial and anti-oxidant composition in food, pharmaceutical and cosmetic industries to increase the durability and prevent the oxidation of nutrients.

In order to investigate the effects increasing of total hardness in water on rainbow trout (Oncorhynchus mykiss) and lettuce plant (Lactuca sativa) growth indices in an aquaponics system, 90 rainbow trout fishes and 260 seedlings of lettuce were randomly introduced into 9 experimental unites. Treatments were affected by increasing the total hardness (calcium chloride) concentration of 0, 100 and 200 mg per liter of water (total 140 mg of total water hardness) for 60 days. Growth indices of fish did not show significant differences (P≥0.05) among treatments, but survival rate showed a significant difference between treatments (P<0.05).  Plant growth indices such as leaf length, leaf width, plant fresh weight, plant dry weight, root fresh weight and root dry weight showed significant differences between treatments (P<0.05). The results of blood biochemical indices showed that increasing the total hardness in water, treatment with 100 mg of calcium chloride per liter of water, showed the highest concentration of calcium of the plasma as 11.36±0.25 mg/dl, showing a significant differences compared to other treatments. Other blood indices such as hematocrit (Hct), mean corpuscular volume )MCV(, hemoglobin (HGB), red blood cell count (RBC), mean corpuscular hemoglobin (MCH) and concentration of red blood cells (MCHC) were not significantly different (P≥0.05) between treatments. The results indicated that adding 100 mg L-1 of total hardness to water (meaning 240 ppm to water), have a positive effect on the biological conditions of the plant and fish in an aquaponic culture of rainbow trout and lettuce.

Bacterial infections are one of the most important threats in the aquaculture. One of the most prevalent infectious diseases in rainbow troutfarms in recent years is Streptococcus in many countries. In recent years, the aromatic plants and their extracts have attracted a lot of attention. This study aimed to evaluate the effect of bacterial infection caused by strain of Streptococcus iniaie on the immune system of fish and the use of the extract of Artemisia sieberi to reduce the devastative effect of this bacterial infection on the immune system of Oncorhynchus mykiss. Reducing levels of the plasma peroxidase, IgM, total complement, lysozyme in fish exposed to bacteria showed the toxic effects of this bacteria on the immune system of fish. However, there was no significant change in the fish fed the extract of Artemisia sieberi and exposed to bacterial infection (P<0.05) compared to control group. This suggests the reinforcement and protective effect of the extract of Artemisia sieberi on the immune system of O. mykiss.

This study aimed to investigate the protective effect of molasses pre-treatment on serum immunity indices of Cyprinus carpio exposed to iron nanoparticles. A total of 250 fish with an average weight of 25±0.62 were divided into four treatments, including without molasses (treatment 1), diet containing 0.5% molasses (treatment 2), diet containing 1% molasses (treatment 3) and diet containing 2% molasses (treatment 4). After 42 days, three fish were taken from each replicate and presented as "no nanoparticles" in the results. Then fish were exposed to 50% of the lethal concentration of iron nanoparticles (96h LC50) for 14 days. After 14 days, three blood samples were taken from each replicate and presented as "nanoparticles" in the results. Blood samples were taken and serum was isolated to measure serum biochemical parameters, including hepatic enzymes (ALT, AST, ALP), glucose, total protein, immunoglobulin, albumin. The molasses treatments had a significant effect on serum immune parameters (P<0.05). With increasing molasses concentration, levels of the serum total protein, immunoglobulin, albumin and glucose were significantly increased. In the treatment of nano iron and nano-iron with molasses, the amount of these indices significantly increased. AST and ALP levels significantly decreased by molasses-fed treatments, but significantly increased in nano-iron treatment in this treatment. In the treatment of nano-iron with molasses, the amount of this index decreased, but it increased significantly in comparison to the molasses group, which means that the molasses alone reduced the index, but in combination with nano-iron, it did not increase the effect of nano-iron, neutralize or even improve it. In the combination of nano-iron and molasses, the amount of ALP and AST indices significantly decreased, that means molasses in combination with nano-iron could improve the nano-iron supplementation, but in the remaining indices, molasses could not neutralize increase effect of nano-iron.

Topmouth gudgeon (Pseudorasbora parva) is considered as an exotic fish for inland waters of Iran. This study was carried out to investigate some reproduction characteristics of this species in some reservoirs of warmwater fish farms in Gonbad-e-Kavous, Iran.A total of 554 fish samples were collected between March and August 2017 using beach seine, and fixed into 10% formalin. The sex ratio was unbalanced in favoure of females, additionally there was a monthly variation in sex ration. Based on GSI results, reproductive season of this species was April-May, the highest GSI was observed in April. The absolute fecundity ranged between 365 and 1262, and the relative one 104 to 625 egg/g. The absolute fecundity had significant positive relationship with fish size (length, weight and age), while relative fecundity showed a negative correlation with fish size (length, weight and age). Egg diameter ranges 0.37 to 0.93 mm, with an average of 0.71-0.74 mm in different reservoirs.

This study was conducted to evaluate and compare the effect of Ergosan particle (Alginic acid) and Alginic acid nanoparticles produced by gamma radiation and ultrasonic wave method in the diet, with the dose of 5 mg/kg. In this research, growth, survival and response to stress were studied in rainbow trout for a period of 8 weeks. The Ergosan immunity-stimulating particles were converted to Alginic acid nanoparticles (Ergosan) by gamma radiation and ultrasonic waves methods. Alginic acid nanoparticles produced by ultrasonic waves had diameter of 70 nm and those produced by gamma radiation had a diameter of 20 nm. The fish with an average weight of 125±9 gr were kept in 300-liter tanks with a storage density of 40 fish in each tank in 4 treatment and 3 replication. The fish were fed ad libitum twice a day. The results showed significant differences in indices under consideration including growth, final weight, weight gain and FCR (P<0.05). There was not any significant difference between treatments in survival rate (P>0.05). The stress test at the end of the treatment period showed that the mean cortisol levels significantly increases, but gamma and ultra-treatments had the lowest response to stress which was significantly lower than control groups (P<0.05). There was no significant difference in glucose levels before and after stress (P>0.05). The results showed that adding nano stimulating Alginic acid produced by gamma radiation to rainbow trout diet, has significant effects on growth and response to stress. It appears that in cultural conditions and weight range mentioned in this study, nano stimulating Alginic acid could be useful for the fish.