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A month after movement of 1800 pieces of L. vannamei (average weight of 16g) from culture ponds in Heleh region to concrete ponds of Bandargah hatchery (Bushehr province) some shrimps showed symptoms such as decrease in growth rate, loss of appetite, dark pigmentation of cuticle and presence of black foci on it, redness of uropods and white, irregular and circular spots on the eye with 2-5mm diameters. For detection of etiological agent samples were taken for PCR, bacteriological and histo-pathological tests. Nested PCR test using IQ2000 kits for detection of major shrimp viral pathogens (IHHNV, WSSV, YHV and TSV) were conducted and all results were negative. In histo-pathological tests, lesions in eyes were liquefactive necrosis of cone cells and cone crystals with infiltration of hemocyte and formation of micro abscess in the diapteric region of eye. In bacteriological tests, a gram negative pleomorphic bacterium of the genus Aeromonas was isolated. However, it seems that this bacterium is the secondary agent and for detection of the primary agent more research is needed. *Corresponding author

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Fermented sausage is a favorite kind of meat-product that has allocated great proportions of meat consumption in the world. For the first time in Iran in this study the production of Fermented sausage from minced meat of common carp was assessed by means of lactic acid bacteria at different incubating temperatures as 15, 25, and 35°C. To prepare the fish sausage, common carp mince was grounded and mixed with NaCl (3%), glucose (3%) and lactic acid bacteria at 5 log CFU/g and afterward were incubated for 48 h. During the incubation of fish sausage, microbiological tests, moisture and protein content, and TVB-N were measured. According to the results, the higher temperature of 35°C stimulated the rapid growth of lactic acid bacteria, resulting in a rapid decline in pH, and consequently suppressed the growth of pseudomonas, Micrococcaceae and Enterobacteriacea.

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The effect of probiotic Pediococcus acidilactici on growth performance, blood and some serum parameters on Caspian salmon (Salmo trutta caspius) was studied. An experiment was designed with five treatments each with three replicates. Two hundred and seventy Caspian salmons average (±SD) initial weight of 6.9 ± 0.1 g were assigned to fifteen experimental tanks. The experimental period was eight weeks. At the end of this period, the growth parameters were measured. In addition, after 8 weeks feeding on experimental diets, hematological parameters and metabolic products (cholesterol, glucose and total protein) were measured. Results showed that feed conversion in five treatments (0.4 g probiotic) significantly was lower than control group. Specific growth rate, final weight and weight gain in treatments (0.2 g) compared with the control group significantly increased. Use of probiotics in the diet, showed no significant differences in hemoglobin, hematocrit and mean cell hemoglobin concentration (MCHC). The mean cellular hemoglobin concentration (MCH) and mean corpuscular volume (MCV) were significantly increased in five treatments (0.4 g) compared with the control group, but significantly decreased red blood cell counts (RBC) in five treatments. White blood cells also increased the amount of probiotics 0.2 g. The results of this study indicated that 0.2 g/kg Pediococcus acidilactici probiotics in the diet could be a useful food supplement and should be used to improve the growth parameters in Caspian salmon.

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This study investigated the ontogeny of some digestive enzyme and explored the effects of photoperiod on stomach (pepsin) and intestine enzyme activity (alkaline phosphatase and N-amino peptidase) in rainbow trout (Oncorhynchus mykiss) larvae juvenile. About 3600 larval rainbow trout in first feeding (18 days after hatching) with an average initial weight 119±0.009 mg were distributed in plastic tanks in four treatments (300 larvae in each replicate). Four light treatments consisting of 14 to 10 h, 10 to 14 h, 4 to 20 h and 24 to 0 h (light: dark), were compared in triplicates for 6 weeks.. Finally, a random sampling from larvae was undertaken on days 1, 3, 5, 8, 10, 15, 20, 25, 30, 39 and 44 days after the onset of first feeding. According to the results, the digestive enzymes activity in fish larvae and juveniles had a similar change trend with age at all photoperiods. In addition, at the end of experiment, the specific activity of pepsin and N-amino peptidase were the highest in 24h Light treatment, but there was no significant difference in specific activities of alkaline phosphatase (p>0.05). The results demonstrated that growth and digestive enzymes activity of rainbow trout larvae and juvenile are improved by applying of longer photoperiod in rearing conditions.

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With regard to increasing the fish meal price, utilization of hygienic and analyzed poultry by product meal as an alternative protein source in diets for Huso huso within growth period were investigated. Six test diets isonitrogenous and isocaleric (contain 42% protein and 20 Mj kg-1 energy) were prepared. Fish meal was substituted by poultry by product at 20% (PBM20), 40% (PBM40), 60% (PBM60), 80% (PBM80) and 100% (PBM100) in base diet, respectively. A total of 180 Huso huso with average (±SD) weight of 107.89±5.9gr were stocked in 18 fiberglass tanks (Voloum:2000 lit,Temperature:20±2C0) and fed satiation to 18 weeks. No significant differences were detected between final weight (FW),weight gain (WG) and specific growth rate of fish fed (PBM0), (PBM20), (PBM40), (PBM60) and (PBM80) respectively. The Highest protein belonged to fish fed PBM20 (%16.97±0.36) with significant difference with PBM40 (% 15.41 ± 0.67), respectively. Body lipid fish fed PBM80 and PBM100 (%6.63±0.016) (%7.49±0.17) were significantly lower than other treatments. The Synchronic hepatosomatic index increased with increasing poultry by product in diets and highest rate were found in fish fed PBM 100 , but except PBM20, visceral index in fish fed other treatments was same. The result showed that up to 80% fish meal could be replaced by poultry by product with no adverse effect on growth and feed conversion ratio for Huso huso within growth period.

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This study was conducted to investigate the effects of periods of starvation and refeeding on some hematological, serum parameters and whole body proximate composition in Caspian salmon (Salmo trutta caspius). 240 samples of the Caspian salmon with an average weight of 13.73 ± 0.63 g were kept in 300 liter polyethylene tanks. Samples were fed twice a day with Rainbow trout commercial feed to the point of satiation. This experiment lasted for 10 weeks with control (without starvation) and 3 starvation treatments including 2, 4 and 6 weeks of starvation followed by 4 weeks of refeeding with 3 replicates. During rearing period, the average of water temperature, pH and dissolved oxygen were 14.15±0.27 ° C, 8.44±0.17 and 6.34±0.24 mgl^-1, respectively. At the end of starvation period, the results of blood parameters showed that starvation significantly increased red blood cells and hematocrit in treatment with 2 weeks of starvation (0.893±0.58 × 10⁶/mm³) and 6 weeks of starvation (42.33±3.21 %, P<0.05), respectively. At the end of trial, the highest value of white blood cells belonged to 6 weeks starvation treatment (14.2±0.12 × 10³/mm³) while the lowest (10±0.60 × 10³/mm³) was observed in the control. Results of the biochemical serum parameters indicated the lowest amount of total protein (1.71±0.88 mg/dl) and glucose (41.35±1.44 mg/dl) were obtained in 6 weeks starvation treatment, right after the starvation period (P<0.05). At the end of the starvation period, the whole body protein content of control was lower than other treatmens (P<0.05), but after 2 weeks of refeeding, whole body protein content of 2 and 4 weeks starvation treatments didn't show any significant difference compared to control (P>0.05). At the end of the experiment, the lowest value of lipid belonged to starvation treatments while the highest value was observed in control (P<0.05). Generally, this can be inferred that Caspian salmon fish can tolerate starvation for 2 weeks without any negative impact on blood and serum biochemical parameters and for 4 weeks on whole body proximate composition. 

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This study was carried out to investigate the effects of different levels of fennel essential oil (Foeniculum vulgare) on some biochemical parameters and salinity stress resistance of Caspian Kutum (Rutilus kutum) fry. For this purpose, Kutum fry with an average initial weight 0.6±0.002 gr were divided randomly in 5 treatments including 0 (control), 100, 200, 400 and 600 mg fennel essential oil/kg diet and fed 3 times a day at a ratio of 7-12% body weight for 60 days. At the end of the experiment, biochemical parameters and salinity stress resistance were assessed. Results of serum biochemical analyze showed that the highest level of total protein and globulin was observed in 600 mg fennel essential oil/kg diet. The highest level of albumin and cholesterol was observed in 100 and 400 mg fennel essential oil/kg diet and the highest level of triglyceride, glucose and cortisol was observed in control (p<0.05). Results of salinity stress (6, 13 and 20 g/l) showed that 100 and 400 mg fennel essential oil/kg diet treatments showed the lowest response to stress and there were the lowest changes in cortisol and glucose levels before and after stress compare to control. Highest survival was observed in 100 and 400 mg fennel essential oil/kg diet. In conclusion results suggested that Fennel essential oil can improve immune system of fries by promoting biochemical parameters (total protein, albumin, globulin, triglyceride, glucose and cortisol). Also plays important role in increasing stress resistance of Kutum fry and the best operation is related to 100 mg fennel essential oil/kg diet.

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This study evaluated the effects of diets including different levels of oregano (Origanum vulgare L.( essential oil on growth indices and fillet quality of rainbow trout (Oncorhynchus mykiss) during refrigerated storage (4±1°C). For this purpose, rainbow trout with an average weight of 69.38±0.44 g were fed with diets containing 0, 250, 500 and 750 mg kg^-1 oregano essential oil for 48 days. After the end of 48 days, growth parameters were measured and also some fishes of experimental groups were filleted and stored at refrigerator (4±1˚C) for 21 days due to quality investigation. Total psychrophilic counts, TBA and TVB-N analyses were done every 7 days (day 0, 7, 14 and 21). The results showed significant differences in some growth parameters including final weight, weight gain, weight gain percent and feed conversion ratio among experimental groups (p<0.05).The results also showed lower amount of total psychrophilic counts and TBA in rainbow trout fillet from oregano groups than control group, during refrigerated storage(p<0.05). As on day 21, the highest amount of PTC was obtained in control (14.39±0.12 log cfu/g) and the least amount of that was obtained in 250 mg kg^-1 (12.38±0.09 log cfu/g).The highest amount of TBA was also observed in control (1.57±0.05 log cfu/g) and the least amount of that was observed in 750 mg kg^-1 (1.20±0.08 log cfu/g) (p<0.05). No significant differences were observed among essential oil treatments. Overally, it could be say using500 mg oregano essential oil can cause improvement of growth and rainbow trout fillet quality during refrigerated storage (4±1°C).
 

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The aim of this study is to chemically hydrolyze of silver carp (Hypophthalmichthys moltirix) viscera and the effect of obtained peptones as a nitrogen source for culture of Listeria monocytogenes. Silver carp viscera were provided by a local market in Sari, Northern Iran. After freeze-thawing of Viscera at 4 °C was used for hydrolysis. Acidic and alkaline hydrolysis was done at two pH 3.3 and 12, and two temperatures of 70 and 85 °C. At the end of hydrolysis DH% (hydrolysis degree) and protein content were measured. Then obtained peptones from these 4 treatments (three replicates for each treatment) used as Listeria monocytogenes culture media at 48 hours and compared with BHI culture media. Results showed that maximum and minimum protein concentration were related to alkaline hydrolysis at 85 °C and acidic hydrolysis at 70 °C, respectively (P<0.05). The highest DH% was related to alkaline hydrolysis at 85 °C and the lowest of  it was related to alkaline hydrolysis at 70 °C (p<0.05). Growth of Listeria monocytogenes in acidic and alkaline produced treatments at 70 °C had no significant differences compared to control (BHI) except at 36 and 48h. But at 85 °C had differences at all hours significantly (P<0.05). This study showed that alkaline hydrolysis in higher temperature is better than acidic hydrolysis and growth of bacteria in fish peptone could be done as well as commercial cultured media. Due to usage of fish viscera and alkaline method with low processing cost, it‘s economically suitable.

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Finding the suitable substitution for fish meal without any negative effect on fish performance is especially important for aquaculture development. In this research, the effect of substitution of fish meal with different levels of earthworm (Eisenia fetida) meal and garlic (Allium sativum) powder were studied on hematological and serum parameters of rainbow trout (Oncorhynchus mykiss) fingerlings. For this purpose, various diets were prepared containing different levels of substitution of fish meal with 0, 25, 50 and 75% of earthworm meal accompanied by 0 and 2.5% of garlic powder. Fingerlings with the average initial body weight of 30±0.27 g were reared in equal conditions for 56 days in 8 treatments and each treatment had three replicates. At the end of the experiment, the results of blood and serum biochemical indices assessments showed that the highest amounts of hemoglobin, hematocrit and WBC were observed in the treatments containing 25% earthworm meal with garlic powder, 25% earthworm meal with and without garlic powder and 75% earthworm meal without garlic powder, respectively whereas the lowest amount of RBC was observed in the treatment containing 50% earthworm meal without garlic powder. MCV, MCH and MCHC values in the treatment containing 0% earthworm meal with 2.5% garlic powder were significantly higher as compared to those of the other treatments except the control treatment (P<0.05). The highest serum protein level was observed in the treatments containing 0% earthworm meal with 0 and 2.5% garlic powder. The lowest amounts of serum glucose and triglyceride were observed in the treatment containing 25% earthworm meal with 2.5% garlic powder. The lowest amount of cholesterol was observed in the treatments containing 75% earthworm meal with 0 and 2.5% garlic powder. Results showed that different levels of earthworm meal with or without garlic powder improved the amounts of WBC, triglyceride, glucose and cholesterol as compared to those of the control treatment. Serum biochemical indices were significantly affected by the diets containing earthworm meal and garlic powder (P<0.05). It was found that the lowest variations in blood and serum parameters were observed in the treatments containing 25% earthworm meal, whereas garlic powder supplementation improved the negative effects of substitution of fish meal with 50% earthworm meal on some of the hematological parameters.
 

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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.
 

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Different hormones are used to induce final sexual maturation in fish breeders and one of these hormones is different analogue of gonadotropin releasing hormone (GnRH) with different trade names. The aim of this study was to evaluate the biological activity of recombinant GnRH produced in the laboratory of Sari Agricultural Sciences and Natural Resources University on the induction and synchronization of ovulation in goldfish broodstock (Carassius auratus).  For this purpose, 20 pairs of mature goldfish were obtained from goldfish breeding centers and transferred to wet laboratory of the Fisheries Department. Fish were acclimated to experimental conditions for 2 weeks then they were divided to 4 treatments. The first, second and third groups received 10, 15 and 20 μg recombinant GnRH/kg body weight, respectively, as well as 20 mg metoclopramide (anti-dopamine)/ kg body weight and control group was injected by physiological saline with 20 mg metoclopramide (0.09% NaCl.) The results showed that the produced recombinant GnRH had the ability to induce final maturation in the studied broodstock and all groups received recombinant GnRH ovulated but none of the control group ovulated. The latency period in the broods injected by dose of 20 μg/kg was significantly lower than the other treatments (p<0.05). There was no significant difference in the total obtained egg and relative fecundity between treatments of recombinant GnRH (p<0.05). The results indicated that the recombinant GnRH has a good biological activity and it can be introduced as a suitable alternative for the treatment of reproductive disorders in goldfish.

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In the present study, the antioxidant activity of different concentrations of protein hydrolysate from Common carp (Cyprinus carpio) head at different hydrolysis time was investigated. For this purpose, 8 Common carp fish with average weight of 0.766±0.034 kg were prepared from market. Fish heads were hydrolyzed by Alcalase (1% v/w at 55˚C and pH 8) at different hydrolysis times (30, 60, 120 and 180 min). The result of proximate analysis showed that the protein content increased  significantly (from 58.31±1.9 to 75.26±1.49%) as a result of  hydrolysis, while the amount of fat and ash decreased significantly (from 16.46±0.87 to 2.37±0.97%; from 27.16±0.64 to 25.34±1.63%, respectively, p<0.05). Also, as the duration of hydrolysis increased, the amount of soluble protein and the degree of hydrolysis increased significantly, so that the highest soluble protein 23.01±0.19 mg/ml and the highest degree of hydrolysis 49.67±0.86% were obtained at the time of 180 min. DPPH radical scavenging activity of protein hydrolysate showed significant increasing trend at different hydrolysis times and different concentrations (p<0.05). The optimum time for DPPH radical scavenging activity (DPPH) was determined at 180 min and IC₅₀ value was obtained 2.08 mg/ml. In addition, with increasing concentration and duration of hydrolysis, the ferric ion reduction power and ABTS radical scavenging activity increased significantly (p<0.05). In general, due to the proper activity of different concentrations of Common carp head protein hydrolysate on DPPH and ABTS radicals scavenging and reduction of ferric ion, it can be stated that this protein hydrolysate can be considered as a dietary supplement with desirable antioxidant function.

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The aim of this study was to investigate the functional properties of bioactive peptides produced from shrimp wastes in processing centers in three degrees of hydrolysis. For this purpose, the wastes of shrimp processing centers were hydrolyzed in three times of one, two and three hours using protamex enzyme and the functional properties of the resulting peptides (SPH₁, SPH₂ and SPH₃) were evaluated. The results showed that with increasing the hydrolysis time from one to two and three hours, the degree of hydrolysis and nitrogen recovery of the process increased significantly (p<0.05). According to the findings, the solubility of SPH₃ was significantly higher than SPH₁ and SPH₂ and its maximum was reported at pH=10, equal to 97.82±1.54% (p<0.05). SPH₁ had higher emulsifying activity and emulsion stability index than SPH₂ and SPH₃. In this peptide, the highest value of emulsifying activity index was reported 68.15±2.84 m²/g, which was related to pH=10. But the maximum emulsion stability index was reported at pH=6 (166.84±5.08 minute). The highest measured foaming activity was 165.52±5.91% which was recorded at SPH₁ and pH=10. Also, the maximum foam stability among the peptides was measured 118.32±3.23%, which was related to SPH₁ at pH=6. SPH₁ had a higher oil absorption capacity (5.92±0.33 ml/g) than SPH₂ and SPH₃ (p<0.05). The highest water holding capacity (5.18±0.71 ml/g) was related to SPH₃ (p<0.05). According to the findings, the functional properties of peptides produced from wastes of shrimp processing centers using protamax enzyme are at an acceptable level for use in various foods.

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The aim of this study was to evaluate the different properties of bioactive peptides encapsulated with a combined coating of nanoliposome and chitosan. Therefore, the wastes of shrimp processing and packaging centers were hydrolyzed using Neuterase enzyme and the antibacterial, antioxidant and antihypertensive properties of the product were evaluated in the form of five treatments of P (free peptides), NP (peptide-carrying nanoliposomes), NP-CH-0.05 (peptide-carrying nanoliposomes with a coating of 0.05% chitosan), NP-CH-0.1 (peptide-carrying nanoliposomes with a coating of 0.1% chitosan) and NP-CH-0.5 (peptide-carrying nanoliposomes with a coating of 0.5% chitosan). The results showed that all research treatments have certain antibacterial, antioxidant and antihypertensive properties. P and NP treatments provided almost equal values for all three properties and their properties did not differ significantly (p>0.05). Chitosan-coated treatments had significantly more antibacterial, antioxidant and antihypertensive properties than P and NP treatments (p<0.05). In chitosan-coated treatments, with increasing the amount of chitosan in the coating, all three mentioned properties were significantly increased (p<0.05). The highest growth inhibition activity of Escherichia coli, Bacillus cereus and Staphylococcus aureus (45.89±0.96, 34.82±0.75 and 49.67±1.45%, respectively), the maximum amount of inhibition of DPPH, ABTS and linoleic acid peroxidation (63.52±2.86, 73.91±0.29 and 89.06±2.11%, respectively) and also the most effective antihypertensive property (37.91±1.29%) were related to NP-CH-0.5 treatment.