Journal of Fisheries
Year:2018 | Volume:71 | Issue:3 |Papers Count:11

Skin aging is accompanied by up regulation of the matrix metalloproteinase (MMP) expression and down regulation of collagen synthesis. Extracted sterols of marine algaes have been reported as anti-cancer agents and antioxidants, which can indicate the potential for anti-wrinkle properties in the human skin. In this study, the sterols extracted from Persian Gulf red algae Gracilaria salicornia were evaluated at concentrations 1. 7, 3. 5, 7, 14, 28, 56 and 112 μ g / ml for determination of procollagen synthesis in human skin cells. To determine the acceptable dose of this precursor, the cytotoxicity test of G. salicornia sterols on the human skin fibroblast cells was tested at levels 2. 3, 4. 6, 9. 3, 18. 75, 37. 5, 75, 150 and 300 μ g/ml. The results indicate increased procollagen synthesis in the skin cells by increasing the concentration of sterols, and the lack of toxicity of this substance in the required dosage of the treatment. The extracts IC50 for human skin fibroblasts was 111 μ g / ml. The effect of extracts on increasing of skin procollagen showed significant differences at concentrations 1. 75 to 112 μ g / ml (P<0. 0001). Therefore, extracted sterols can play an important role on reducing the skin aging process due to the synthesis of skin cells procollagen. More research is needed for other uses of algae sterols for the use of cosmetic products.

Considering the widespread use of antibiotics in aquaculture and the lack of farmer’ s attention to the harmful effects of the antibacterial drugs administration, study of the antibiotic effects on the biological indicators of aquatic animals is necessary. In this study, in order to probe of oxytetracycline effects on blood parameters (red blood cells, white blood cells, hematocrit and hemoglobin) in rainbow trout (Oncorhynchus mykiss) affected by Aeromonas hydrophila, the effects of antioxidant butylated hydroxytoluene (BHT) on the side effects of antibiotic treatments was investigated. By examining the results of this research, which was carried out on 120 rainbow trout fish with an average weight of 175. 92± 30 g in four treatments (Control, treated with oxytetracycline, treated with oxytetracycline and BHT 0/5% and 0. 8% daily diet) and three repetitions, in period of 61 days, BHT antioxidants showed effective roles in improving side effects of oxytetracycline on hematological parameters. On the other hand, due to the lack of significant differences between 0. 5 and 0. 8 % doses (daily diet) of BHT on blood parameters, it seems the dose of 0. 5% is more economic in rainbow trout aquaculture.

Habitat models are applied to estimate species abundance and diversity using habitat parameters that can be used in exploitation and conservation of many aquatic species. Habitat models are effective tools in estimating species abundance and diversity of aquatic communities using habitat parameters has high importance in exploitation and conservation of aquatic resources. Identifying models with the best performance and habitat parameters with the highest importance, would affect appropriate utilisation of this tools and in making optimal management decisions. The present study evaluated performance of four models (multiple linear regression, partial least square regression, support vector machines and random forest) in prediction of biodiversity indices in fishes of a river in the southern Caspian Sea. In addition, importance of environmental parameters in prediction of those indices were calculated. Multiple linear regression and partial least square regression had weak performance. Support vector machine and random forest had the best performance. Various environmental parameters had varying importance across the examined models. In conclusion, support vector machines and random forest are suggested as suitable models for prediction of biodiversity indices of the southern Caspian fishes.

Gamaridae is one of the most diversified and prominent family of Amphipoda. This order provides the main food for the most fish species and are so sensitive to environmental pollution, which leads to their ecological and economic importance. However, regarding to high degree in morphological and ecological differences among the different species of the order, the first step to study these group of animals is to identify the species. The main aim of this study was to collect and identify Gammarus species distributed in the rivers of the eastern part of Tehran Province, including Jajrood, Hablehrood and Lar. In order to collecting the samples, ten sampling points in different parts of three rivers were selected. Sampling was carried out seasonally from October 2013 to June 2014. 20 samples were taken from each point by dredge device and kept in ethanol to transfer to the laboratory for further experiments. For identification the samples to species level, some of the available classification keys were applied. The samples were identified by classification key at species level and results showed that all of samples were G. komareki. Then, molecular assessments by DNA extraction, DNA qualification and isolation the mitochondrial gene in COI segment by using universal primers were conducted; at the end of the process was finished by gene sequencing. The obtained sequence was compared by Genbank. The results showed that G. komareki has varied populations in the rivers of eastern part of Tehran province. Although there was no significant morphological difference among the populations, their different abundance revealed the difference in the rivers environments.

In this study, the effect of ethanolic extract of dill (graveolens Anethum) on growth and immunological parameters of rainbow trout fingerlings was evaluated (average initial weight of 12± 0. 32 g). A basal diet was supplemented with levels of 0 (control), 500, 1000, 1500 and 3000 mg ethanolic extract of dill kg-1 to formulate five experimental diets. After 56 days of feeding trial, fish fed diet with 1000 and 1500 mg kg-1 had the highest final weight compared to control but in terms of feed conversion ratio, specific growth ratio and protein efficiency ratio did not show a significant difference compared to control group. All treatments had a high survival rate and did not show significant differences with each other. The highest activity of lysozyme and complement was observed in the 1500 mg kg-1 treatment but did not significant difference compared to the control group (P>0. 05). The results showed that concentrations of 1000 and 1500 mg kg-1 of ethanolic extract of dill increased the weight in these factors and the concentration of 1500 mg kg-1 treatment had better effect on immunity.

Biogenic amines are nitrogen-based organic compounds, which are basically produced by decarboxylation of amino acids. The presence of high amounts of biogenic amines in food represents deterioration and undesirable quality of food. In this study, changes in the amount of biogenic amines produced in the muscle of the croaker (Otolithes rubber) as a chemical indicator of spoilage caused by different methods of thawing (water, air, refrigerator and microwave) were evaluated. The croaker fishes were kept in powdered ice and transported to the processing factory, where they were deep frozen at-36° C through a freezing tunnel, followed by storage in cold store at-18° C for 4 months. The experiments were conducted by application of different thawing methods of water, air, refrigerator and microwave, followed by simultaneous monitoring of changes in the biogenic amines (histamine, putrescine, tyramine and cadaverine). The results showed a significant decrease in the amount of histamine during thawing in refrigerator compared to the other methods and control (P<0. 05). Also, a significant decrease was observed in the amount of putrescine produced during thawing by microwave technique compared to the other methods (P<0. 05), but there were no significant differences between the amounts of tyramine and cadaverine produced by different thawing methods compared to the control treatment (P<0. 05). The highest levels of histamine and putrescine were observed in thawing methods of air and refrigerator respectively. Based on the results of this study, it can be concluded that thawing by refrigerator method can be suitable technique for defrosting the frozen croaker fish.

In this project, the effect of Origanum vulgare’ s extract (0, 1, 2 and 3%) on the quality and shelf-life of grass carp (Ctenopharyngodon idella) fillets was investigated during 14-day storage in the refrigerator. Treatments at days 1, 4, 7, 10, and 14 were investigated in terms of TVB-N, TBA, moisture content, WHC and TVC (total microbial content). Based on the results, TVB-N in all treatments were significantly reduced compared to control (P<0. 05). Its lowest content was observed in samples coated with 3% of O. vulgare’ s extract. The same trend was observed for TBA in all treatments. At the end of storage period, the highest and lowest TVC were observed in control and 3% treatment, respectively. There was no significant difference in the water holding capacity of all treatments. The results showed that different concentrations of O. vulgare’ s extract have significant antimicrobial and antioxidant effects on the grass carp fillets during the storage period in the refrigerator. According to the results of the evaluation of treatments, the shelf-life of the coated fillets in storage conditions was estimated in the control group up to 4 days and in treated treatments 7 to 10 days. Based on the results, the treatment with 3% of O. vulgare’ s extract is recommended as the best treatment for effective storage of grass carp fillet quality during refrigerated storage.

Due to complexity of nemacheilid’ s taxonomy based on their morphological characters, researches try to use other proper diagnostic characters such as osteological ones. Hence the current study aimed to describe osteological structures of Paraschistura altato provide its diagnostic osteological characters. For this purpose, seven specimens were collected from the Sistan basin and after clearing and staining, their skeletal structures were examined. According to the results, Paraschistura altacan be distinguished based on some osteological characters, including nail shaped of prevomer, having four basibranchials, 10 pterygiophores, 6 hyporals, aveolar structure of bony swim bladder and straight or somewhat serrated supraneural 3 from other members of this genus in Iran.

Length-weight relationship, growth pattern, condition factor and age composition of Alburnus chalcoides in the southwest coasts of the Caspian Sea (Astara, Anzali and Kiashar) were examined from September 2017 to October 2018. A total of 77 fish were caught using beach seine. The mean length and weight of fish were 19. 25± 5. 17 cm and 76. 78± 83. 92 g, respectively. Fish age ranged from 0-4 years and age class 0-1 accounted for 81. 8% of the examined specimens. Considering the growth pattern, the regression coefficient (b) was bigger than 3. The figure obtained from Pauly equation was 5. 28 which is larger than the t value of Pauly table (1. 66), suggesting a heterogeneous or alometric growth pattern for the species under question. The CF values were 0. 83± 0. 14 and 0. 82± 0. 11 in males and females, respectively. Mean gonadosomatic index was higher in females and significantly varied in females (8. 04± 4. 82) as compared to males (3. 05± 1. 47). Mean hepatosomatic index was 0. 79± 0. 49 in males and 0. 75± 0. 44 in females.

This study aimed to investigate the effect of edible chitosan coating containing Cinnamomum verum essential oil onchemical and microbial properties of silver carp fish fingers during storage in refrigerator. Fish fingers were separately immersed in chitosan coating (2%), cinnamon essential oil (1. 5%) and chitosan coating (2%) + cinnamon essential oil (1. 5%) for 1 minute, then packed and stored in refrigerator (4° C). Chemical (pH, Peroxide value (PV), thiobarbituric acid (TBA) and total volatile base nitrogen (TVB-N)) and microbial parameters (total viable count (TVC) and psychrotrophic count (PTC)) were measured at 0, 3, 6, 9, 12, 15 and 18 days. The results showed that with increasing storage time the pH, PV, TBA and TVB-N values increase significantly (P<0. 05). The TVC and PTC counts of fish fingers increased significantly during refrigerated storage (P<0. 05). Chemical and microbial indicators of chitosan coating (2%) + cinnamon essential oil (1. 5%) treatment showed a little change in comparison with the other treatments during storage a significant difference with other treatments during storage (P<0. 05). According to the results, it can be concluded that the fish fingers coated with chitosan coating (2%) + cinnamon essential oil (1. 5%) have affected in compared to the other treatments and increased the shelf life of fish finger for 3 days.