نشریه علوم آبزی پروری ایران
سال یازدهم شماره 1 (بهار و تابستان 1402)

In the present study, the morphological variation and some biological parameters (growth pattern and condition factor) of 46 specimens of Chondrostoma regium collected from the Gamasiab, Dinevar, Qarasu and Zab rivers were analyzed. A total of 22 morphometric and 6 meristic characteristics were measured and counted, respectively. To investigate the morphological variations between studied populations, morphometric and meristic characteristics were analysed using One-way analysis of variance, Kruskal-Wallis, Principal Component Analysis (PCA), and Canonical Variates Analysis (CVA). The results showed that 16 morphometric and 5 meristic characteristics had significant differences (P<0.05). CVA analysis of morphometric traits showed that the populations had a high overlap and only the Zab River was separated from others, also in those meristic, Zab populations were separated from each other. Based on the results, C. regium showed significant morphological differences in meristic and morphometric discriminability characteristics. The growth pattern was isometric for Gamasiab, Dinevarr, and Qarasu populations but positive allometric for the Zab population. The condition factor was determined between 0.97 (Zab) and 1.06 (Dinevar), and there were no significant differences found between the studied rivers.

There are numerous studies about the positive effects of rosemary on growth performance, digestive enzyme activity, antioxidant and immune systems, and disease resistance in different fish species. On the other hand, the efficacy of γ-irradiation to enhance the biological activities of rosemary has been demonstrated. Therefore, this study aimed to evaluate the potential of rosemary in three forms (crude powder, alcoholic extract, and irradiated alcoholic extract) on rainbow trout (Oncorhynchus mykiss) serum antioxidant system, liver-related enzyme activities, some metabolites and digestive enzyme activities. After synthesizing the alcoholic extract of rosemary, γ-irradiation was performed at 30 kGy with a Cobalt-60 gamma irradiator. In the in vivo trial, fish specimens (~225.36 g) were randomly distributed into four groups with three replicates. After the seven-day adaptation period, fish were fed with the control diet or the treatment diets (crude powder= T1, alcoholic extract= T2, or irradiated alcoholic extract = T3) for 50 days. The results showed that the highest serum glucose level was seen in the control group (118.43±4.16 mg dl-1) whereas the lowest level was noted in the T3 group (41.25±1.59 mg dl-1). In parallel, triglyceride levels decreased in the T2 and T3 groups compared with the control group. Digestive enzyme activities also improved in all treated groups, especially in the T2 and T3 groups, compared to the control group. Liver-related enzyme activities also decreased following the administration of the T3 group. Serum antioxidant enzyme activities also increased in T2 and T3 groups compared with the control group with the highest SOD and CAT activities shown in the T3 group. In conclusion, the present study showed that 50-day dietary administration of rosemary alcoholic extract, especially in the irradiated form, could enhance some serum metabolites, antioxidant enzyme activities, liver-related enzyme activities as well as digestive enzyme activities in rainbow trout.

The present study was performed to investigate the effect of replacing fish meal with sunflower meal in the diet and its effect on the growth performance and biochemical compositions of Rutilus frisii fingerlings. For this purpose, 240 specimens with an average weight of 1.14±0.8 g and an average total length of 5.03±0.3 cm in 12 tubs with a density of 20 in each and in four different treatments of 0 (control), 25, 50, and 75% sunflower meal with food ration formulated with the same percentage of protein, fat and energy levels were tested for eight weeks. In the parameters of food conversion factor, protein efficiency rate, growth factor, weight gain, length increase, average daily growth, survival percentage, final length, initial and final weight, no significant differences were observed (P>0.05), but in terms of mean status coefficient, a significant difference was observed (P<0.05). Also, the analysis of fish carcass analysis parameters showed that there was no significant difference between the treatments in terms of carcass moisture percentage (P>0.05), but in terms of ash percentage, protein percentage and carcass fat percentage, there was a significant difference was observed (P<0.05). The results showed that different levels of replacing sunflower meal with fish meal have no negative effect on the growth performance of R. Frisii. Therefore, to reduce the cost of feed production and economic efficiency of the studied fish breeding, up to 25% of sunflower meal can be replaced with fish meal in the diet composition.

In this study, the effect of different levels of microplastics and copper, alone and in combination, on the number of total hemocytes and different hemocytes in freshwater crayfish (Astacus leptodactylus) was conducted. For this purpose, 378 crayfish with an average length of 10.64±0.76 cm and a weight of 41.12±5.15 grams were divided into 27 aquaria. The exposure period was 28 days, the number of total hemocytes and different hemocytes were checked at the end of the experiment, and hemolymph samples were taken from the crayfish. The results showed that the number of hyalinocytes in the samples exposed to 1 mg/L polyethylene microplastic and 1 mg/L copper sulfate treatment was less than in the control group. The number of granulocytes increased in the treatment of 1 mg/L of polyethylene microplastic and 1 mg/L of microplastic combined with 0.5 mg/L of copper sulfate compared to the control group, and for semi-granulocyte cells, 1 mg/L of fine plastic combined with 0.5 mg/L of copper sulfate significantly decreased and the treatment with 1 mg/L of copper sulfate also had a significant increase compared to the control group (P<0.05). Also, the number of total hemocytes in the treatments of 0.5 mg/L of microplastic combined with 1 mg/L of copper sulfate and the treatment of 1 mg/L of microplastic combined with 1 mg/L of copper sulfate decreased significantly compared to the control treatment (P<0.05), finally it can be concluded that polyethylene microplastic and copper metal alone and together can be among the polluting and damaging factors to the immune system in freshwater crayfish.

This study was conducted to evaluate the effect of different concentrations of selenium nanoparticles on the hematological, serum biochemical indices, and antioxidant system of Nile tilapia (Oreochromis niloticus). Fish with an average weight of 31.1±1.0 g were distributed in 12 fiberglass tanks and were fed for 56 days with different concentrations of selenium nanoparticles including 0, T1 (0.5), T2 (1) and T3 (2 mg/kg of selenium nanoparticles). The highest number of red blood cells, hemoglobin and hematocrit were observed in T2 and T3, which statistically showed a significant difference with other treatments, especially the control treatment (P<0.05). The results showed a significant difference in the total protein and globulin levels of fish fed with a diet containing 1 and 2 mg/kg of selenium nanoparticles. In this study, the addition of 2 mg/kg of nano selenium to the diet lead to a significant decrease in glucose, cholesterol, and triglyceride levels, and the lowest values of these parameters were observed in the group fed with 2 mg/kg of nano selenium, which is significantly different from others. The activity level of liver enzymes including ALT and AST was the highest level in the control treatment and those lowest were observed in the 2 mg/kg nano selenium treatment (P<0.05). There was a significant difference in the amounts of catalase and superoxide dismutase enzymes among fish fed with 1 and 2 mg/kg of selenium nanoparticles compare to the treatment of 0.5 mg/kg of selenium nanoparticles (P<0.05). In conclusion, the effect of different concentrations of selenium nanoparticles, especially in the concentration of 2 mg/kg, had positive effects on the hematological, biochemical indices, and antioxidant system of Nile tilapia and this nanoparticle can be a suitable agent for improving available food quality in aquaculture.

The aim of this study was to evaluate the effect of Aloysia citrodora extract on the growth parameters and liver enzyme activities of Nile tilapia (Oreochromis niloticus). Two-hundred-forty fry with an initial weight of 10.53±0.23g were for the experiments. During 8 weeks experimental period, 4 treatments including treatment 1 (commercial diet or control treatment), treatment 2 (a diet containing 2.5g A. citrodora extract/kg diet), treatment 3 (a diet containing 5g A. citrodora extract/kg diet), and treatment 4 (diet containing 7.5g A. citrodora extract/kg diet) were used. Based on the results, the highest final weight, weight gain, specific growth rate, and condition factor were observed in treatment 4. Moreover, no significant differences in AST, ALT, and ALP were found between treatments. The results of the study showed that a diet containing 7.5g A. citrodora extract/kg diet could increase growth performance in O. niloticus without negative effects on their liver.

Cosmetic products with marine-derived ingredients instead of synthetic ingredients are indeed particularly attractive to consumers, and that is why the demand for these products has increased in the last decade. However, natural resources, including marine resources, are limited and should not be overexploited because their regeneration involves the passage of many years. One of the solutions for natural resource depletion is to recover their discards and by-products. Therefore, this issue has led to the use of marine discards and by-products produced in the fishing industry as a sustainable source for extracting high-value ingredients that are used in the cosmetic industry. These ingredients such as collagen, chitin, natural calcium phosphates, astaxanthin, and phycobiliproteins could be utilized as antioxidants, anti-photoaging, anti-wrinkle, anti-acne, and anti-inflammation in cosmetic formulations. As a result, in this study, according to the importance of the subject, the potential of marine discards and by-products to extract effective cosmeceuticals was discussed.

Dunaliella salina microalgae is a unique eukaryotic microorganism that has a high range of tolerance against environmental fluctuations including salinity, temperature, and light. The aim of this study was to determine the growth factors and content of fatty acids in D. salina under salinity and ultraviolet conditions. The experiments were conducted at three different salinities (150, 200 and 250 ppt) under UVB and UVC irradiations in 3 replicates. Algae growth rate and total algae biomass were measured by counting the number of cells every alternate day for 11 days by hemacytometer. The fatty acids profile was measured by gas chromatography and the amount of total fat using a soxhlet device. The growth rate of algae in most of the treatments under high salinity stress, UVB and UVC irradiation was significantly lower compared to the control group (P≤0.05). The highest cell counts were detected in the control one (2.4 million cells/ml) and UVB-150 treatment (1.98 million cells/ml) on day 7. But despite the higher cell count in the control group, the highest fresh wet weight of algae was obtained in the UVC-200 ppt/salinity group. Substantial differences were detected in the fatty acids profile between the treatments (P≤0.05). Algae cultured under UVB-200 contained the highest PUFA-n3 (20.05%) and the sum of PUFA (32.05%), while the highest PUFA-n6 (13.96%) was found in the UVC-150 group. Algae cultured at 250 ppt salinity without UV irradiation had the highest level (52.75%) of saturated fatty acids (SFA). It was concluded that UV irradiations and high salinity suppresses the growth but improves the synthesis of polyunsaturated fatty acids.

Babylonia spirata is one of the important commercial oyster species in the world. The ecological basis of the habitats of this mollusk in the coastal waters and in the areas of the continental plateau is a significant help to fishermen and operators. Therefore, to identify the ecological characteristics of the Babylon Sea snail habitat in the northern waters of the Oman Sea, water sampling was done to determine temperature, pH, salinity, dissolved oxygen, nutrients, turbidity, and sediment, the total organic matter and the type of substrate, Babylon species to determine CPUE was done monthly from September 2021 to May 2022. The results showed that the average water temperature during the study period was 27.79°C in Konarak, 26.99 in Pezam, and 28.5 in Pasabandar and Bris. The average salinity in Kanarak, Pozem, Bris, and Pasbandar stations were 39.33, 26.99, 39.25, and 39.25 g/L, turbidity 5.48, 2.5, 7.25 and 7.25 FTU, acidity 8.25, 8.22, 8.18 and 8.18, DO 6.6, 7.06, 6.97 and 6.97 mg/l, nitrate 1.35, 1.16, 1.11 and 1.11 mg/l, nitrite 0.04, 0.02, 0.055 and 0.055 mg/l, ammonia 0.05, 0.19, 0.01 and 0.01 mg/liter,  phosphate 0.37, 0.23, 0.25 and 0.25mg/liter, and the organic matter 0.64, 0.52, 1.67 and 1.67%, respectively. The results revealed that nutrients play an important role in the density of Babylon in this region. With the increase of nutrients, the density of Babylon increases with a sharp peak and reached the maximum in October and November, and after that, with the decrease of food, the density decreases. Based on multiple linear regression analysis, the nitrite was highly related to the amount of catch per unit effort of the Babylon Sea snail.

Most of the plastic materials used for food packaging are non-biodegradable, resulting in more environmental pollution. Hence, this study was designed and conducted to measure the effect of toxicity of the PSNPs while transferring from the diet to the body of the fish (food concentrations = 0, 0.1, 10, and 100 mg/kg) on juvenile rainbow trout (Oncorhynchus mykiss) in a 28-day chronic treatment and the control group (food concentration= 0mg/kg) after the 7-day adaptation period, in three repetitions (15 juvenile trout were included in each repetition per concentration). In addition, changes in two genetic biomarkers of the immune system and stress in the expression profile of the liver and spleen tissues indicated that following the increase in the concentration of PSNPs, the tumor necrosis factor-alpha (TNF-α) and expression level of heat shock protein 70 (HSP70) in both liver and spleen tissues significantly increased with the increase of mRNA transcription (P<0.05). Based on the obtained results, the release of NPsPS was confirmed for health and safety at the cellular-molecular level in the aquatic sample under study, and it is likely that if this nanomaterial is released in the aquatic environment, it will induce adverse environmental effects.