JOURNAL OF FISHERIES SCIENCE AND TECHNOLOGY (JFST)
Year:2019 | Volume:8 | Issue:4 |Papers Count:7

Aims The present study was aimed to evaluate the effect of different levels of choline chloride (ziro, 250, 500, 750, 1000, and 2000mg/kg food) on the growth performance, carcass compositions, and haematology of Caspian salmon (Salmo trutta caspius). Materials & Methods 270 fish pieces weighing 8. 82± 0. 38 in 18, 250-liter fiberglass tanks (15 fish per tank) with 3 repetitions per treatment with one of six experimental diets (control diet, Cho250, Cho500, Cho750, Cho1000, and Cho2000) were fed for 10 weeks. Findings Final weight, weight gain, specific growth rate index, protein yield ratio, obesity ratio, and feed conversion ratio of fish fed with diet containing appropriate levels of choline (750 to 1000mg/kg choline), were significantly higher than the fish fed with control diet and Cho250 diet (p≤ 0. 05). There was a significant decrease in the feed conversion ratio of Cho750 and Cho1000 treatments compared to control treatment. It can be acknowledged that the Caspian Sea salmon cannot meet the physiological needs of choline by biosynthesizing choline from the liver or methionine. By increasing choline in the diet, the amount of protein and fat in the carcass increased significantly, but the moisture content of the carcass decreased (p≤ 0. 05). Also, moderate amounts of fatty liver fish fed with control treatment and Cho250 treatment were significantly lower than other treatments. The results showed a negative relationship between the increase in choline levels and the activity of hepatic blood enzymes (p≤ 0. 05). Conclusion In order to increase the growth process, strengthen the immune system, and optimally combine the carcass, the most appropriate amount of choline chloride is 750-1000mg/kg in the diet of Caspian Sea salmon.

Aims The aim of the present study was to investigate the effect of cooking methods (frying and microwave), chitosan additive and freezer storage time on the Huso fillet in terms of sensory and color evaluation and weight changes. Materials & Methods Fish fillets were frozen at-18° C for 4 months. Also, they were deforested, fried, and microwaved (day 0, second month, and fourth month). Half of fillets were added to 1% acid-soluble chitosan. This experiment was designed in 4 treatments: T1 (fried sample without chitosan), T2 (fried sample containing 1% acid-soluble chitosan), T3 (microwave cooked sample without chitosan), T4 (Microwave cooked sample containing 1% acid-soluble chitosan). Fillet weights were measured before and after cooking. Sensory and colorimetric properties were evaluated after cooking. Findings The use of 1% acid-soluble chitosan had no significant effect on sensory parameters and colorimetric factors (p>0. 05). Weight changes in fried fillets were increased over time but decreased in microwave-cooked fillets over time. Conclusion The use of acid soluble chitosan 1% had no significant effect on the sensory indicators compared to the control group. In terms of colorimetric factors, chitosan had a positive effect on yellowness index. The weight changes of the microwave-cooked fillets were better than the fried ones. The fillet without chitosan at zero time was in the best condition in terms of sensory evaluation and colorimetry compared to the other fillets.

Aims The aim of the current study was to investigate effect of pellets contain Spirulina platensis on physiological indices of Ctenopharyngodon idella. Materials & Methods The number of 450 grass carps (10± 0. 5g) were divided into six treatments (three replicates) and fed with pellets contain 0, 0. 5, 1, 2, and 4% spirulina for eight weeks, compared to forage (control). At initial and the end of experiment, growth and nutrition indices, meat composition, hematological and immunological indices, and carotenoid of fish were mesured. Means were compared by one-way ANOVA and Tukey test (p≤ 0. 05). Findings The best total length, weight, FCR, SGR, body weight gain percentage, nutritional efficiency, daily growth, and dietary intakes were observed in 4% spirulina treatment, which showed a significant difference with control (p˂ 0. 05). Fat percentage of meat in 4% spirulina treatment had difference with control significantly (p˂ 0. 05). The number of RBCs in 1% spirulina treatment had a significant difference with control (p˂ 0. 05). The highest Hct and Hb were observed in 1% Spirulina treatment, and the highest WBCs and eosinophils were observed in 4% spirulina treatment, which had significant difference with control (p˂ 0. 05). Also, the percentage of lymphocytes in algae-treated treatments was significantly higher than control and non-algae-treated treatment (p˂ 0. 05). The highest level of lysozyme, bactericidal and anti-trypsin activity of serum were in 4% spirulina which had significant difference with control (p˂ 0. 05). Carotenoid of fish meat didn’ t show significant difference among treatments. Conclusion Food pellets containing 4% spirulina is recommended for improving growth and nutrition, hematological and immunological indices in grass carp.

Aims For the purpose of marketability and consumer preferences, two types of hand moisturizing products (alginate gel and fucoidan cream) produced from Sargassum algae, the present study was conducted and then evaluated with a common commercial sample as a control. Materials & Methods Gel and two cream samples were prepared in 3 jars of 10g to evaluate 30 individuals as panel members. Evaluation was performed using one product per week and with a one-week break between sessions. The designed questionnaire consisted of sociological questions and 12 characteristics of the products that were rated with 3 points of preference. The Friedman test and the scoring method were used to analyze the ratings and identify the final product, respectively. Findings Two characteristics of produced cream and gel (moisturizing and shelf life) were at a significant level. The gel had the highest moisturizing capacity and the cream had the highest shelf life. Consumers paid more attention to the nourishing and hydrating properties of the skin, being organic and soft in choosing the suitable moisturizer for their hands. They like moisturizing cream of 250g jar. Nutrition and hydrating, therapeutic effect, and skin repair were also ranked as high priority. Finally, the fucoidan moisturizing cream gained the highest preference in market. Conclusion The fucoidan cream produced from Sargassum algae compared to alginate gel from this alga, as a moisturizer with suitable shelf life and having other hand cream properties, can be an acceptable commercial product in the market.

Aims Histopathological study is one of the most appropriate ways to evaluate the effects of contaminants in aquatic organisms. The aim of the present study was to evaluate the histopathological changes and histopathological alternation index (HAI) in liver tissue of Pomadasys kaakan and Lutjanus johnii in the Oman Sea. Materials & Methods In this study, 18 number Pomadasys kaakan and Lutjanus johnii were captured from 3 stations including Ramin, Konarak, and Haft-Tir by gillnet in winter 2016. In order to study the type and severity of tissue lesions, fixation stages in Bowen’ s solution, tissue processing in tissue processing device, paraffin impression, tissue sections 4-5 microns thickness with microtome, stained with hematoxylin and eosin were done for liver tissue of both fish species. Findings Tissue lesions observed in fish livers included hepatocyte vacuolization, enlargement of sinusoid, adipose cell accumulation, blood congestion, nuclear pyknosis, hemorrhage, and necrosis. In addition, these tissue lesions were higher in Haft-Tir station and lower in Ramin station than in other stations. In Haft-Tir station, histopathological alternation index in liver tissue of both fish species were higher than other two stations. Conclusion Due to the high traffic of the Haft-Tir dock and its close proximity to other docks in the area, the accumulation of pollutants at this station is high and lead to more severe tissue lesions in fish.

Aims Nowadays, microalgae use to produce biologically active drugs and pharmaceuticals. The carbon source is an essential factor for Spirulina maxima growth. It is valuable to find the appropriate carbon source and its concentration to achieve high levels of biomass in the shortest cultivation period. Therefore, in the present study, the effect of different carbon sources (sodium carbonate, sodium bicarbonate, glucose, and molasses) with different concentrations (16, 24, and 32gL-1) on growth and biomass production was evaluated. Materials & Methods Microalgae were grown in 11 treatments with 3 replications at laboratory temperature (28± 3° C) and 1350± 100Lux light intensity (24-hours exposure-time). The maximum specific growth rate and doubling time were calculated according to nonlinear modeling by Wolfram Mathematica 11. 3 software at a 99% confidence interval. Findings The highest biomass concentration (gL-1) at the highest carbon source concentration in the first 5 days belongs to molasses (3. 083), glucose (2. 094), sodium carbonate (0. 869), and sodium bicarbonate (0. 835). Biomass production of treatments except for glucose in medium was increased by increasing concentration from 16 to 32gL-1. Although molasses has reached the highest biomass production during the first 5 days of cultivation, the greatest effect on increasing specific growth rate belongs to the glucose sample. Conclusion The carbon source and its concentration had a significant effect on growth and biomass production. Glucose was selected as an effective carbon source for growth with a concentration of 24gL-1. Moreover, the highest concentration of treatments had shown the least effect on the specific growth rate.

Aims The present study was aimed to extract gelatin from Siberian sturgeon waste and using it in film making. Materials & Methods Gelatin was extracted using NaOH and HCl. After evaluating the extracted gelatin properties consist of bloom grade, pH, zeta test, melting, and setting temperature and time, the edible film was prepared using casting method. Findings The results showed that the extraction efficiency of the gelatin was %20. 06. In addition, the protein content, pH, degree of gel hardness, and setting temperature and setting time and melting temperature and melting time of gelatin were reported as 79. 2± 0. 6%, 4, 160. 2± 0. 4g, 13. 1± 0. 2° C in 180. 3± 0. 5 seconds and 19. 33± 0. 5° C in 140. 66± 0. 5 seconds, respectively. Zeta potential indicated a positive surface charge in gelatin. The thickness, moisture, solubility, tensile strength, elongation at break, and permeability of gelatin film were reported as 0. 05mm, 10. 2± 1. 5%, 79± 3. 7%, 30. 01± 0. 7MPa, 77. 5± 3. 6%, and 3. 54± 0/08g mm/h mm2kpa×10-6, respectively. SEM images of the film showed a smooth structure without cracking. Moreover, the FTIR result depicted the formation of amide bonds in the regions of 3277. 62, 1633. 92, 1530. 11, and 1236. 49cm-1. Conclusion Due to the efficiency and gelatin traits, and the mechanical and physical properties of the edible film, it can be used as a good candidate for the production of biodegradable films in food storage.