Iranian Scientific Fisheries Journal
Year:2013 | Volume:22 | Issue:3|Papers Count:8

In this study, some non-specific immune responses and hematological parameters in rainbow trout juveniles (16g mean weight) and their resistance to Streptococcusis were invetigated following dietary administration of 3 concentrations (0.5, 1, 1.5g/kg of feed) of Echinacea purpurea extract. The non-pecific immune response and hematological parameter compared with control group for 60 days. Evaluated parameters included were of C3, C4, (complement components), superoxide ions (respiratory burst), lysozyme activity, number of WBC, percentage of blood lymphocytes, monocytes and neutrophils. At the end of trial, the relative survival rate (RSR) of fish was evaluated against S. iniae. The results showed that the levels of C3, lysozyme activity, superoxide ions, number of WBC and percentage of neutrophils in the experiment groups (the highest concentration, 1.5g/kg of feed) were increased significantly compared to the control group. Whereas, no significant difference was found in the value of C4 and the percentage of monocytes and lymphocytes in comparison to the control group. The relative survival rates of fish following challenge with Streptococcus iniae, were 91.11 and 44.44 percent in experiment (Echinacea purpurea, concentration of 1.5g/kg of feed) and control group, respectively. In conclusion, the results of the present study demonstrated that Echinacea purpurea. extract enhanced the non-specific immune system and fish resistance against streptococcusis, suggesting that this extract might be used as immunostimulant in fish feed.

Sargassum oligocystum and Nizamudiinia zanardinii are the most abundant algae distributed in the north of Persian Gulf and Oman Sea. In this study after sampling and preparation of S. oligocystum by Chroform-Etanol (3-1) solvent and N. zanardinii by methanol has been extract. Separation and purification of the compounds was carried out using thin layer, general and inverse column chromatography, Cephadex and high-performance liquid chromatography (HPLC). Structural elucidation of the constituents was based on the data obtained from HNMR, 13C-NMR, HSQC, HMBC, DEPT and Cephadex LH-20. The steroids compounds separated from above algae were identified as 22-dehydrocholesterol (1) cholesterol (2) fucosterol (3) 29-hydroperoxystigmasta-5, 24 (28) -dien-3β-ol (4) 24-hydroperoxy-24- vinylcholesterol (5) a mixture of 24 (S) -hydroxy-24-vinylcholesterol (6) and 24 (R) -hydroxy-24- vinylcholesterol (7) and ostreasterol (8) based on their spectral data and from comparison with those previously reported in the literature

Due to study the food regime of Arius dussumieri, a total of 132 specimens were collected from Oman sea waters, Sistine&Baluchistan province. The stomach content, were taken into consideration and it was found that the amount of full, semi-full and empty stomachs were 31, 33 and 36 percent, respectively, of which the highest frequency was in winter (74%) and the lowest was in summer (24%). On the other hand, the fullness index was studied with the highest and lowest value for spring (44%) and winter (5%), respectively. The GaSI shows that A.dussumieri, has better feeding in spring and summer but feeding (up in male) was decreased in autumn and winter. The Food Preference (FP) Index was estimated as: Fishes (39%), Crustacean (40%) and Molluscs (20%) namely all of them are considered as minor food in all four seasons. The most important food items were identification as fishes: Carangidae, Engraulidae&Leiognathidae, crabs: Portunidae & Porcellanidae, shrimp: Alpheidae, cephalopods: Loliginidae&Opisthoteuthidae, gastropods: Muricidae&Naticidae.

Silver carp and kilka burgers fusion product is a mixture of minced meat, fish, Tofu and silver carp, flavors, fillers, various herbs and spices. This study designed to investigated the corruption indicators and integrated manner burgers shelf life during cold storage being performed at a temperature of -18°C. Four treatments and Tofu burger meat mixed with various percentages of Silver carp was chosen. Indicators include TVN, TBA, was over Four months of PV at -18°C. The results showed that the zero – phase testing of volatile nitrogen in meat fish, Tofu, were larger than in meat. The changes in peroxide measurements over 4 months, were increased and the 100% increase in treatments 1 and Tofu fish. The largest mean increase was about 3.5±0.05. The total volatile nitrogen increased during 4 months, in treatment and control of phase 1 to 4 out of the standard range. This increase was significant at 95% for all treatments. Changes in TBA measurements over 4 month increased, at TBA level in treatment 1 and control plots in the first phase of its five standards that its limited formaldehyde was 2 milligrams Malone.

Effect of antibacterial activity of different concentrations Cuminum cyminum essential oil (0, 0.005, 0.015, 0.045, 0.135, 0.405%) and nisin (0, 0.125, 0.25, 0.75 μg/ml) was carried out to evaluate in lab and food model (fillets of Rainbow trout) on control Streptococcus iniae for 15 days at 8ºC in 2013. In lab, micro-dilution method was used for determine MIC and MBC of nisin and essential oil, so used for food model. Results showed that MIC and MBC essential oil and nisin were 0.015, 0.005% and 0.25, 0.125μg/ml, respectively. Since 15 days, according to the results, statistical significant showed between concentrations of nisin and essential oil with control treatment (P<0.05). Results showed growth of bacterial delayed in different samples treated with nisin and essential oil singly to 3 and 6 days and in combination 6 days. The highest synergistic effect of nisin with essential oil in 0.135 and 0.405% concentration of essential oil and 0.75 μg/ml nisin in 8ºC.

Streptococcusis is the one of the most important bacterial fish diseases with outbreak in rainbow trout farms in Iran. The fish farmers have been largely suffered from huge economic losses due to the Streptococcusis outbreaks in different rainbow trout farms in Iran. The present study assessed the effects of some environmental risk factors on incidence of streptococcusis in rainbow trout farms in Haraz River in Mazandaran Province, Iran. A suit of environmental factors including water temperature, nitrite, nitrate, ammonium, water turbidity, DO, water Debi and total count of bacteria were explored as influential factors. Fish and water samples were randomly collected from 10 farms on a monthly basis throughout a year. Isolation and recognition of strep strains were made using biochemical and PCR tests and the data were analyzed by logistic regression method. According to the results, 20% of the differences were explained by the logistic model. Management of these factors might decline the rate of disease outbreak.