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The effect of nonylphenol on vitellogenin and zona pellucida 3.1 expressions in the liver, spleen, gill and muscle tissues of the juvenile Persian sturgeon were investigated. The fish were initially injected per kilogram of their body weights with 100mg nonylphenol, 5mg 17 beta estradiol, and 2ml peanut oil carrier agent (respectively, for the main treatment, positive and negative controls), and had the extracted RNA of their tissues converted into cDNA. Afterwards, RT-PCR reaction for each tissue sample was done separately. Results showed vitellogenin gene was expressed only in the liver, but zona pellucid 3.1 gene was expressed in the liver as well as the spleen of the fish exposed to nonylphenol and 17 beta estradiol. No vitellogenin gene in the spleen, gill and muscle was expressed; no gene for zona pellucida 3.1 was either observed in the gill and muscle. The expression rate of vitellogenin gene was 9.95±2.48 for the treatment with 17 beta estradiol and 2.85 ± 0.35 with nonylphenol; the expression rate of zona pellucida 3.1 was 9/98 ± 2/51 for exposed treatment with 17 beta estradiol and 3.37±0.35 for the treatment with nonylphenol. In conclusion, considering the meaningful effect of nonylphenol on vitellogenin and zona pellucid 3.1 expression in liver and spleen, it could be used for detection of xenoestrogen biomarker in the Persian sturgeon.

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The aim of the present study was to evaluate the effects of enriched Artemia with fish and soybean oils supplemented with vitamin E on growth performance, stress resistance, antioxidant enzymes activity and lipid peroxidation of Persian sturgeon (Acipenser persicus) larvae. Five experimental diets including non-enriched  Artemia (control diet), Artemia enriched with soybean oil supplemented with 15 or 30% vitamin E (S15 and S30 diets) and fish oil supplemented with 15 or 30% vitamin E (F15 and F30 diets) were used. The larvae were fed to apparent satiation for 17 days. The results indicated that fish fed enriched Artemia had no significant differences compared with control group in terms of growth and survival, but increase in vitamin E levels from 15 to 30 % improved growth performance and resistance to salinity stress. Vitamin E content in fish fed S15 and S30 diets was significantly higher compared with the other treatments. Antioxidant enzymes activity in fish fed non-enriched Artemia, F15 and F30 diets were higher. The highest TBA value was observed in fish fed non-enriched Artemia. The results demonstrated that the addition of vitamin E to the fish and soybean oils for Artemia enrichment could reduce oxidation of oils and beneficial for the health and quality of larvae. In conclusion, enrichment of Artemia with soybean oil supplemented with 30 % vitamin E (S30 diet) is recommended for feeding Persian sturgeon larvae.

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The effects of starvation periods on physiological response of the juvenile Persian sturgeon, Acipencer persicus, was assessed through such stress factors as glucose, cortisol and hepatic enzymes for a period of 8 weeks. For this purpose, in a randomly designed experiment, five groups of fish (108.04 ± 0.28 gr) in 3 replicates were starved for a period of 0 (control), 1, 2, 3 and 4 weeks and fed them to satiation after their starvation lags. Blood plasma glucose and cortisol during starvation periods did not significantly change (p>0.05). This indicates high performance of this specific in maintenance of blood glucose during starvation and recovery of glucose level after feeding. However, plasma hepatic enzymes level in fasting treatments increased (p<0.05), but reached the control level after 4 weeks of feeding. Considering the role of liver enzymes in gluconeogenesis and taking into consideration the constant plasma glucose and cortisol during periods of food deprivation, it seems that liver enzymes in the Persian sturgeon during food deprivation play a key role in stabilizing blood glucose. Considering the role of liver enzymes in gluconeogenesis, and taking into consideration the constant plasma glucose and cortisol during periods of food deprivation, In this study, it seems that liver enzymes in the Persian sturgeon during food deprivation play a key role in stabilizing blood glucose.

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In this study, effects of freezing and two thawing methods on food quality of Persian sturgeon fillets (Acipenser persicus) were evaluated. Fresh Persian sturgeon fillets kept frozen at -20ºC up to 4 months, and then thawed by two different thawing methods (in a microwave oven and in a refrigerator at 4ºC). Freezing- thawing increased fat and decreased protein, moisture and ash contents. Thawing in microwave resulted in less decrease in moisture content compared to refrigerator thawing and caused an increase in protein content. Protein solubility decreased after freezing- thawing but it was significant only in few pHs (in both thawing methods). 4 months frozen storage and then defrosting resulted in a decrease in –SH group content. The microbial count increased after freezing and thawing (p<0.05), however the increase was less after microwave thawing. Both thawing methods showed higher L^* and b^* values and smaller a^* value compared to control sample (P<0.05).  

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Effects of sodium salt solutions on physicochemical and sensory characteristics of refrigerated Persian sturgeon (Acipenser persicus) fillets during 12 days of storage were investigated. Fillets were dipped in solutions (2.5% w/v) of sodium acetate (SA), sodium lactate (SL), sodium citrate (SC) and distilled water (as control) for 10 minutes and then packaged. An assessment of TBARS, FFA, pH, heme iron and sensory attributes (flavor, color and odor) was carried out on 0,3,6,9 and 12 days past the storage time. Results indicated that TBARS values of each sample increased with the storage time (P< 0.05). Control showed the highest values of TBARS while sodium acetate sample had the significantly (P< 0.05) lowest figures among the treatments (1.04 for SA versus 2.34 for control). Lipid hydrolysis assessment revealed that the sodium salt treated samples, especially sodium acetate, acquired the lower FFA amounts (P< 0.05) as compared with control. No significant differences (P> 0.05) were observed among the pH values of the treatments. Heme iron assessment showed that the samples treated with sodium acetate contained more heme iron as compared with control. Sensory assessment revealed more desirable scores for the sodium acetate treated group as compared with others samples. The order for the sodium salt treated effects was: SA> SC> SL. As a consequence, sodium salts, in particular sodium acetate, might be considered as effective tools in preventing the quality degradation of the fillets, resulting in an extension of their shelf life.

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The changes of total calcium content of Persian sturgeon, Acipenser persicus follicles were investigated during different stages of germinal vesicle migration. Total calcium content increased during maturation and ripening of the oocytes i.e. migration of nucleus toward the animal pole. According to data, the total calcium of follicles with Polarization Index (PI: the ratio of the distance of the germinal vesicle from the animal pole over the animal-vegetal oocyte diameter×100) less than 5.2 (group I) were significantly higher than those in groups with 5.7< PI< 8.1 (group II) and PI> 9.4 (group III). Also, there were no significant differences observed in total calcium content of follicles with PI> 9.4 (group III) and follicles retained for 20 days in body cavity with PI> 10.5 (group IV). As well, there was a significant negative relationship observed between PI values and total calcium content of follicles. It is concluded that calcium is accumulated during the final oocyte maturation in Persian sturgeon.