نشریه علوم و فنون شیلات
سال یازدهم شماره 1 (پیاپی 37، زمستان 1400)

In this study, the effectiveness of 4 killed VNN vaccines along with three types of adjuvants was evaluated by both immersion and injection methods. About 540 fish weighing 7-10 g of ozone (Acipenser stellatus Pallas 1771) were considered. Vaccination was performed in two stages one month apart, and one month after the second recurrence, exposure to the acute live virus was performed. During this period, the mortality rate of immersion and injection groups was 12.9% and 19.8%, respectively, compared to 100% mortality in the control group. Blood sampling was performed to assess immune factors (superoxide dismutase, lysozyme) in four stages before the first vaccination in the adaptation period, after the first vaccination, after the second vaccination one month and after exposure to live virus Acute was performed to identify changes before and after exposure to the virus. The results of the present study showed that immunization vaccination in the vaccinated group with the vaccine containing IMS 1312 SEPPIC adjuvant significantly higher levels of superoxide dismutase 1745 IU / MI (p<0.05) and lysozyme 40.6 (p<0.05). Compared to other groups, which proves its better efficacy compared to other vaccines. Therefore, a vaccine killed with 75% IMS 1312 SEPPIC adjuvant can be recommended for vaccination against VNN.

The long nose sturgeon (Acipenser stellatus, Pallas, 1771) is an anadromous sturgeon species, yet little is known with regard to salt bath effect on bacterial adhesion on superficial organs of this species and its growth. This study was conducted to determine the optimal salt bath concentration on growth parameters and total bacteria count on juvenile stellate sturgeon gill and skin. A total of 200 fishes with mean initial weight 494.5 ± 2.17 g and length 62.63 ± 0.18 cm (mean ± SD) were randomly distributed into 12 concrete pools in groups of 25. Fishes exposed to acute salinity of 0, 5, 10, and 15ppt for 30 minutes. Salt bath is used 5 times for 60 days (1, 15, 30, 45 and 60). At the end of 60th day, growth indices including body weight, SGR, BWI, ADG, PER and FE revealed a significant increase at 5ppt salinity (P< 0.05) and fishes exposed to 15ppt exhibited the poorest growth. No statistical significant difference was observed between control and other treatments in total protein and albumin, also in total bacteria count in gill and skin of fishes (P>0.05) but higher levels of total protein and albumin and lower level of total bacteria observed in 5ppt treatment. The results of this study indicate that high acute salinity may compromise the growth of juvenile long nose sturgeon and suggest that, in commercial operations, salinity should be 5ppt.

The current study was conducted to identify the factors affecting the consumption of fishery products by households in Shiraz. All households of Shiraz city were the research population which 381 of them were randomly selected using simple random sampling method. The face validity and reliability of the questionnaire were confirmed by a pilot study among 30 households of Neyriz Fars, respectively (Cronbach's alpha coefficients were computed between 0.62 and 0.83). The results of path analysis indicated that the households` income, the education level of the households` head, hygiene issues and awareness of fisheries products` benefits had a direct, positive and significant effect on the amount of fisheries products consumption by households. Also, the households’ income and hygiene issues had an indirect and positive effect on household attitudes toward fisheries products and then on the amount of consumption of these products through the mediator variables of awareness of fisheries products` benefits, sensory indicators and preference to buy from the direct market of fisheries. Moreover, the direct effect of awareness of the fisheries products` benefits, it had also an indirect and positive effect on the amount of fisheries products consumption by households through the mediator variables of market preference and attitudes toward fisheries products consumption. Finally, the study suggested that the media could play an effective role on modifying the households` attitude toward fisheries products consumption by educating different types of fish cooking methods as well as improving their awareness regarding the fisheries products` benefits.

Because of the importance of osmoregulation in success of the juvenile Caspian Roach (Rutilus caspicus) release, maintenance and their restoration, this study was performed with the aim of the evaluation of these fish (average weight of 1.4 g± 0.018 g) to the salinity tolerance of the Caspian Sea by abrupt and gradual transfer methods on two different occasions of short-term (24 hours) and long-term (21 days). For this reason, 360 juvenile roaches were distributed to 9 different experimental treatments (each of them with 3 replicates) with 1) increased abrupt salinity (direct transfer to the Caspian Sea water), 2) increased gradual salinity (3 ppt for every 24 hrs) and 3) the Control group (freshwater). In order to evaluate the ion regulation, osmolality, Na+, K+ and Cl- were measured in fish. Some immune responses related to the increased salinity (immunoglobulin and lysozyme) and stress indices (cortisol and glucose) were also measured. Based on the obtained results, the fish in both treatments of increased salinity showed high percentage of survival. All parameters related to ion regulation were decreased after a primary increase. Furthermore, the trend of cortisol and immunoglobulin changes were negatively correlated showing decreased stress response and increased immune system for both salinity transfer methods. Thus, the roach juveniles (1-2 g) are able to be transferred into the Caspian Sea directly.

Aeromonas hydrophila is an opportunist pathogen in fish and responsible for wide range of fish diseases. In this study, the effect of different levels of curcumin in the diet on growth and resistance to infection with Aeromonas hydrophila in common carp (Cyprinus carpio) was investigated by peritoneal injection. For this purpose, six concentrations of 0.2, 0.4, 0.6, 0.8 and 1% of different levels of curcumin were mixed with a special feed for carp. 360 common carp with an average weight of 50±4/7 g (divided into six groups), each group was divided into 60 fish and 20 fish per replication. Live Aeromonas hydrophila was exposed to concentrations containing Cfu/ml10 of Aeromonas hydrophila for 10 days and post-challenge mortality was compared between treatments.The results showed that administration of 0.8 and 1% curcumin caused a significant increase In the reduction of losses after challenge with Aeromonas hydrophilis in bacteria in treatments of 0.8 and 1% curcumin showed significant compared to the control treatment (p <0.05).In general, it can be said that the most appropriate concentration of curcumin in feed to increase resistance to infection Bacterial cells are 0.8 and 1%.

The present study was designed to evaluate the effect of acetaminophen on hematologic and blood biochemistry of rainbow trout in a 4-day period. To that end, total 300 fingerlings with an average body weight of 12.5±2.5 g were randomly allocated into 15 polyethylene tanks (with 100L volume). Fingerlings were exposed to five concentrations of acetaminophen, namely, 0, 0.01, 0.1, 1. 10 mg/L for 4 days. Hematologic and Biochemical Parameters of Rainbow Trout (Oncorhynchus mykiss) exposed to Acetaminophen were measured. According to the results, the number of white blood cells was significantly different compared to the control group and other treatments at concentration of 10 mg/l. The number of red blood cells, hemoglobin, mean hemoglobin volume (MCV) and hematocrit were higher in the control group and And the lowest amount was observed at a concentration of 10 mg/l and There was a significant difference between these parameters in different treatments. There wasn´t significant difference in mean corpuscular hemoglobin concentration (MCH) between experimental treatments. There was a significant difference in serum lysozyme enzyme and complement (ACH50) activity in fingerling exposed to acetaminophen. There was a significant difference in cortisol and glucose levels in different treatments so that the most amount of cortisol and glucose showed in the control group and the less amount was observed in treatment 5.

Malathion and diazinon are widely used organophosphate pesticides in the agriculture fields, especially in the north provinces of Iran. In the current study, lethal concentrations of diazinon and malathion were determined based on big head carp calculated death rates at 24, 48, 72 and 96 hours using probit analysis. Then, in a separate experiment and according to the obtained LC50, the effects of these toxins on fish hematological parameters was evaluated in which fish were disturbed in 10 treatments with 3 replicates (4 different doses of diazinon, 4 different doses of malathion and 1 control for each toxin) for 7 days. Fish were exposed to different sub-lethal concentrations of each toxin (12.5, 25, 37.5 and 75% of lethal concentration (LC50 96h). After 7 days, blood samples were collected and hematological parameters including hematocrit, hemoglobin, red blood cells count, the total number of white blood cells and white blood cell differential count (the percentage of lymphocytes, monocytes, neutrophils and eosinophils) were examined. The results of acute toxicity test showed that diazinon is more toxic to big head carp compared to malathion. Also, hematological studies of big head carp exposed to diazinon showed a significant reduction in red blood cells and white blood cells with increasing toxin concentration. Meanwhile, the percentage of neutrophils remarkably increased while lymphocytes significantly decreased along with increasing the concentration of diazinon.

This study aims to compare effects of sources levels of zinc on growth and carcass quality, some haematological and serological indices of juvenile beluga sturgeon, Huso huso (Linnaeus, 1758). A number of 315 juvenile beluga sturgeon (8.4±0.29) were fed in 21 500 lit fiberglass tanks (15 fish per tank) under 7 experimental diets including 1 control diet plus 6 diets containing zinc (mg per kg of diet) in two forms of mineral (zinc sulfate) (ZnSul15, ZnSul30, and ZnSul60 treatments) and organic (chelated with methionine) (ZnMet15, ZnMet30, and ZnMet60 treatments) with three replications per treatment for 12 weeks. The best values of final weight and feed conversion ratio were observed in the ZnMet15 and ZnMet60 treatments. Red blood cells, hemoglobin, and hematocrit showed an incremental trend influenced by increased zinc supplement. Increased carcass protein in the ZnMet30 treatment was significant compared to the control, ZnSul15, and, ZnSul30 treatments (P≤0.05). Reduced carcass lipid in the ZnSul30 and ZnSul60 treatments was significant compared to the other treatments (P≤0.05). Serum triglyceride and cholesterol decreased in the ZnMet treatments compared to the control treatment. Reduced serum glucose in the ZnMet15 and ZnMet60 treatments and also increased serum lysozyme in the ZnMet30 and ZnMet60 treatments were significant compared to the control treatment (P≤0.05). Results demonstrated that most of the indices had better performance in the ZnMet treatments comparted to the other treatments and are proposed as an optimal diet for juvenile beluga sturgeon.