ALBERT

Description: Study on Viral Nervouse necrosis (isolation, characterisation and pathogenesis) in Golden grey mullet in the Caspian Sea and study of pathogenecity and possibility of transmission to the other fish species (Sturgeon fishes, Rutilus frisii kutum and reared Rainbow trout and Carp) Viral Nervous Necrosis (VNN) is a worldwide disease affecting several species of cultured marine fish. For the past two decades, betanodavirus infections that cause Viral Nervous Necrosis (VNN) have emerged as major constraints on the culture and sea ranching of marine fish in almost all parts of the world. More than forty species mainly of marine origin have been so far affected and this number is likely to rise in future following the introduction of new species and the increase of aquaculture trade. Unknown acute mortality occurred in wild golden grey mullet Lisa auratus and Liza saliens in Iranian waters of Caspian Sea in recent years. In order to isolation and confirmation of causative agents of golden grey mullet mortality in the Caspian Sea, a complementary research investigation project was designed in 2005 and approved immediately in Iranian Fisheries Research Organization (IFRO). Many diagnostic aspects such as Virology (Cell culture and Elctereone Microscopy), Hemathology, Bacteriology, Histopathology, Molecular biology (NestedRT-PCR), Heavy metals measuerment and Serology (IFAT and IHC) were employed in mentioned multidiciplinary project. About 322 moribund fish samples which revealed skin darkening, erratic swimming behavior such as spiral and belly-up at rest and high distention of swimming bladder. Suspected samples were collected from coastal capture sites in iranian north proviences in 2006 till 2009. Targets tissue such as brain and eye were removed in strile condition and then kept in -80oC frezzer for cell culture and Nested-RT-PCR. Other tissue samples from liver, kidney, intestine, stomach, gill, skin and muscle, gall bladder and gonads were taken and fixed in 10% buffer formalin and same parts fixed in glutaraldehyde 3% for histopathology, IHC and EM respectively. Cytopathic effect (CPE) was observed in those cell cultures just six days after inoculation with the dilutions of the tested 312 homogenate supernatants. CPE in monolayers of cells cultured (SSN-1 cell line) was characterised by thin or rounded, refractile, granular cells with vacuoles. Nine samples were positive in virology assay. Nested- RT-PCR was done on suspected tissue samples and supernatant of CPE positive samples and 21 tissue samples and all CPE positive samples were positive. IFAT was selected as a confirmatory method for identifying viral strains replicating on cell cultures and carried out with rabbit anti-betanodavirus serum on suspected tissue samples and some smears of CPE positive samples. Some bright points approved betanodavirus antigen and confirmed cell culture and Nested-RT-PCR findings. In fixed tissue samples widespread and massive vacuolation were observed in brain, spinal cord, retina and optical nerve. In order to confirmation of diagnostic findings , IHC was done with monoclonal antibody antibetanodavirus and some red-brown points were observed. Theses findings revealed expected viral antigens and confirmed previous results. Moreover, virus particles with 25-30 nm in diameter were visualized in infected brain and retina using positive staining in TEM. Also pathogenicity test was employed to confirm the obtained results. So Guppy fish Poecilia reticulata and sturgeon fry were used instead of the experimental host due to ease of handling and susceptibility. After 15 days post infection, guppy bathed in VNN-infected tissue culture with 104 TCID50 showed clinical signs similar to naturally infected Golden grey mullet, and the mortality rate reached up to 100% in 75 dpi. When target organs were examined by cell culture isolation, serology, and histopathology, all revealed the presence of virus in the Guppy. Suspected supernatant injected to sturgeon fry through intravitreous injection and widespread vacuolation were observed in brain and spinal cord buy IHC and Real time PCR were negative. In conclusion, with attntion to obtained results in this investigation such as ecological factors, clinical signs, histopathological, virological and bacteriological results, molecular analysis, (IHC, IFAT, PCR), TEM demonstration, serological and hematological findings, it could be confirmed that VNNV was the main causative agent for disease outbreak in Golden grey mullet in Southern coastline of Caspian Sea.

Description: Iranian Fisheries Science Research Institute

Description: Published

Description: There are many factors affecting aquaculture insurance in Iran. In spite of existing formulation for warm water fish culture in Iran, there was several aspects and new revisions were remind. In this study we focused on risk assessment as well as insurance procedure to find the better management practices on running insurance in the country. 360 farm in tree provinces (guilan, Mazandaran, Khozestan were selected for risk analysis program. Data were collected throw questionnaire forms. The project was carried out in fore disciplines 1) risk analyzing for manageable and unmanageable accidents and their deductible rates 2) revise premium forms , claim forms, inspection forms 3) new formulation for insurance management 4) guide lines for diagnostic futures and prevention of manageable accident.

Description: Iranian Fisheries Science Research Institute

Description: Published

Description: The main purpose of this study was survey on achieving recombinant DNA vaccine (live delivery) against streptococcusis for Rainbow trout (Onchorhynchus mykiss) Immunization. Initially, a total of 515 samples were collected from the head kidney of diseased fish (weigh 50_ 200g) in 72 farms of 8 provinces. Approximately, 40% (206 samples) of specimens were infected to Streptococcus species. Then were isolated 172 DNA samples and consequently, five pathogenic species have been identified, including S. iniae, S. faecium, S. agalactiae, S. dysgalatiae, and S. uberis. The enzyme phosphoglucomutase (PGM) has recently been discovered to play an important role in polysaccharide capsule production and virulence in S. iniae. Therefore, was initially isolated S. iniae and cloning phosphoglucomutase gene. Then, the PGM gene was amplified successfully and cloned in pTZ57R cloning vector. The recombinant plasmid was sub cloned into pETD uet-l expression vector by restriction enzymes and confirmed by PCR. Meanwhile, for amplifying simA and cpsD genes were used universal primers pNZ8148 and special for simA and cpsD genes.The recombinant bacteria Lactococcus lactis (NZ9000) was used for transformation the plasmid into Lactococcus lactis. Vaccination was performed by oral, bath and injection (peritoneal) methods. The efficiency of g2 was better than g1in these three methods and all of groups. The determination of IgM level, or detection of anti S. iniae antibody was carried out by using ELISA. The results revealed that there was a significant (p〈0.05) difference between the level of IgM in all three methods and experiment groups compare to control group. The results of challenge of vaccinated fish with S. iniae showed that fish RPS in all of groups except group 3 (42.63 percent) were more than 50 percent while, in control group was 21.43 percent. The highest fish RPS was belong to group 11(61.25 percent) and statistical analyses revealed that significant (p〈0.05) difference between fish vaccinated RPS, compare to control group.

Description: Iranian Fisheries Science Research Institute

Description: Published

Description: The main goal of anesthesia in rainbow trout is decrease mobility and reduce stress of fish while breeding, and also facilitate operation such as manipulation to Tagging, Biometry, Sorting, Inspection and Sampling for pathology test. In the present study, Aqueous and alcoholic extract of tobacco plant (Nicotiana tabacum) for Anaesthetizing Rainbow trout (Oncohrynchus mykiss) in 3 weight groups: fry (less than 80 g), growing(about 200 g) and breeding(larger than 1500g) were used. The effective dose of tobacco in treatments 200, 400, 800 and 1600mg/lit in aqueous and 0.7, 1, 1.7 and 3.5mg/lit in alcoholic extract were tested. Totally, we can say that tobacco extract Anaesthetizes the rainbow trout in less than 3 minutes and recovery time is less that 5 minutes. Regarding to anesthetizing time, recovery time and fish relaxing during anesthesia, aqueous extract applies more gentle anesthesia in rainbow trout, and dose 200 to 800 mg/lit of aqueous extract were more successful. Also Regarding to significant correlation between doze and Anesthetics extremity and recovery time (P〈0.05), lower dose of tobacco extract can be used to making fish calm for transportation.

Description: Published

Description: This study aimed to investigate the effects of 5- parameter dissolved oxygen, PH, nitrite, nitrate and temperature of the water on Streptococcosis incidence in two groups of fry and grower fish. Research was performed at west Mazandaran province -Tonkabon region in 12 rainbow trout selected farms. Research conducted in 3 farms with well source water , 8 farms with water source of the river of Dohezar and one farm with water source of the river of Azarood, during 12 consecutive months.From 1390/04/01 to 1391/04/01, once time each month , and in each time 10 fish randomly sampled, inlet water were sampled simultaneously. Of 1350 sampled fish 607 fish with an average weight 22.04 gr , average length 12.59 cm were in fry category and 743 fish with an average weight 156.25 gr, average length 23.32 cm in were grower category. Streptococcosis observed only in grower category. Of 72 fish with clinical signs of the disease, 14 numbers were positive Streptococcosis (19.44%) and 58 numbers were negative Streptococcosis(80.55%). Three fish from grower category has not any clinical signs of disease and seemed to be healthy but were positive Streptococcosis in examinations (0.22% of total fish sampled. Fish with clinical signs of the disease but negative Streptococcosis were of at least 55.1 gr and at most weight 417 gr respectively. The results showed that 47.07% cases of Streptococcosis happened at 15.6 °C water temperature, 35.29% at 16.98 °C and 17.64% cases happened at 18.04 °C so that 100% of Streptococcosis cases was observed at the average temperature of 16.99 °C. In addition, the survey results show that despite relatively high levels of nitrite in source water of farms from wells, nitrite does not effect on the disease incidence. It seems that an optimal level of dissolved oxygen in water is effective in reducing the effectiveness of nitrite in this disease. According to equation coefficients logit model is as follows: According to Logit model, it seems that for every degree change in temperature and pH of water, morbidity change will diminish 0.37 % and 1.74 % respectively. 80.56% of fish sampled that had the clinical symptoms, was ranging from an average weight of 5.1 gr (fry) and 417 gr (grower fish), that despite having clinical signs of the disease were negative Streptococcosis. Isolation of Staphylococcus bacteria as well as Gram-negative bacilli from fish with clinical symptoms similar to the symptoms of Streptococcosis, may indicate the involvement of other pathogens in fish clinical signs.

Description: Iranian Fisheries Science Research Institute

Description: Published

Description: The national research plan with title of "Study on health status of Iran Coldwater hatchery and rearing farms" was done in order to identification and tracking of main causative agents of recent mortality in Iran Coldwater hatchery and rearing farms and recognize of infected zones and design of landscape distribution of Epizootic Coldwater fish diseases in the country. This plan was conducted parallel and in same time in some polar provinces of Coldwater fish production such as Mazandaran, Gilan, Ardebil, West Azerbaijan, East Azerbaijan and Kurdistan in three years from 2006-2008. In this regard, about 23,21 and 20 farms in Mazandaran province, 30 farms in West and East Azerbaijan and Kurdistan provinces and 19 farms in Gilan and Ardebil were selected as randomly and tracking were done yearly from 2006-2008. This research was conducted according to regular planning consists of farms visit that was done according to statistical plan and completion of Questionnaires and sampling. The findings in Mazandaran province revealed that fish infections background and infectious diseases were increased in period of 2006-2008. In fact, 56% of all fish farms in 2006, 71% in 2007 and 85% in 2008 were recorded as infected farms. In other side, average weight of fish final products was more 500gr in consume market. So, regarding to long period of fish culture in mentioned fish occurrence of more morbidity could be expected. The streptococcus infections were most important fish bacterial diseases that have more incidence and pathogenicity in collected questionnaires. Also it revealed more occurrences in summer season in above 15oC temperature in affected fish farms. Also, Enteric Redmouth Disease (ERM) and Saprolegniasis were reported as second and third degree in examined farms. Meanwhile, findings of control, prevention and treatment of our survey revealed that using of antibiotics and detergent materials were increased in mentioned province. Indeed, 34.7% of all fish farms in 2006, 71.4% in 2007 and 75% in 2008 have applied treatment operation and using of detergent materials in affected farms. In other side, frequent using of Erythromycin antibiotic was reported several times in 2008 so fish farmer faced to Bacterial resistance and should be using from Florfenicol as alternative antibacterial. Also, in feed sampling from all fish farms about 3 fish farms in 2006 and 5 fish farms in 2008 were faced with food poisoning that originated from high TVN and peroxidase in fish food consumed. These farms revealed mass mortality that stopped after change feeding regime. In conclusion absence of fish health management could be considered as main agent of mentioned mortality in Mazandaran province. The findings of our survey in West and East Azerbaijan and Kurdistan revealed that absence of sufficient experiences in fish farmers and their neglect from water quality concepts, farm cleanness, using of suitable detergent materials for fish ponds and instruments and disability in continuous monitoring of physic-chemical factors of consumed water could be considered as most important problems. So, fish morbidity and mortality, growth decrement and low production rate were expected. Unfortunately, despite the occurrence of infectious and non- infectious diseases in examined fish farms, there were no documents and information about diseases history, clinical signs in dead fish, feeding regime, fish mortality (rate of daily mortality, age and weight of moribund fish), treatment operation, drugs usage, growth rate, physico-chemical factors and fish density. So planning for control and prevention of mentioned diseases were unsuccessful in affected fish farms. Also, occurrence of some epizootic fish viral diseases such as VHS, IPN and IHN were observed frequently with mass mortality about 40100% in some examined fish farms that produced some tragic economic lost in the mentioned provinces. Similarly, some bacterial, fungal and parasitic diseases were observed repeatedly in some inspected farms such as Flavobacterium, streptococcus infections. Also, some unknown causative agents in parasitic diseases were observed several times such as Dactylogyrus, Gyrodactylus, Ichthyophthirius multifiliis, Trichodina, Chilodonella, Diplostomum and fungal diseases such as Saprolegniasis. In conclusion it seems that absence of fish health management, inadequate rate of hygienic technical services, absence of quarantine programs for transfer of new eyed-eggs, juvenile and live broodstocks packages without health certificates from authorized organizations, uncontrolled entry of foreign eyed-eggs (France, Denmark, Australia and Armenia) and neglect in using of suitable detergent materials for fish ponds, instruments, consumed water and infected eggs, not screening of broodstocks in hatcheries could be considered as most important causative agents in occurrence of infectious diseases and main problems in affected farms in mentioned provinces. Similarly, our findings in Gilan and Ardebil provinces revealed that their problems were similar to other provinces. In fact, neglect in establish of necessary Infrastructures in fish farms and dereliction in health management concepts could be considered as main reasons of occurrence of fish infectious and non-infectious diseases in studied fish farms in mentioned provinces. In fact, often fish farms visited hadn't suitable structures without control and prevention approach. There were not observed detergent using, quarantine programs and prevention methods. Entrance of unknown persons, birds and wild animals were ordinary in mentioned farms. Unfortunately level of farmer’s knowledge was low and no training courses and extension programs were planned by authorized organizations. Meanwhile, food storages were unsuitable and food packages were stored in inappropriate situation so poisoning conditions were increased in examined farms. In conclusion it could be finalized that Coldwater fish farms in Gilan and Ardebil provinces situated in insufficient position and correction of current situation are needed urgently. In final elicitation, it would be mentioned that lack of basic infrastructures could be introduced as most important reasonfor spread of diseases, mortality and related economic losses in studied provinces. Therefore, attention to environmental affairs and access to Sustainable Development are recommended. Also consideration of biosecurity regulations and health management concepts would be important requirements for modification and reformation of Coldwater fish farms in examined provinces towards A Better Tomorrow.

Description: Iranian Fisheries Science Research Institute

Description: Published

Description: There are many factors affecting aquaculture insurance in Iran. In spite of existing formulation for cold water fish, warm water fish and shrimp culture in Iran, there was several aspects and new revisions were remind. In this study we focused on risk assessment as well as insurance procedure to find the better management practices on running insurance in the country. 360 farm(for carp in tree provinces Guilan, Mazandaran, Khozestan),150 (for trout in tree provinces Fars, Mazandaran, Chamahal ) and all 340 farm(for shrimp in four provinces Sistan ,Hormozgan, Bushehr, Khozestan) were selected for risk analysis program. Data were collected throw questionnaire forms. The project was carried out in Two disciplines 1) risk analyzing for manageable and unmanageable accidents and their deductible rates 2) new formulation for insurance management.

Description: Iranian Fisheries Science Research Institute

Description: Published

Description: This research was done in a trout farm in Kohkiloyeh and Boyer- Ahmad province. The main object of this study was comparing of two sources of astaxanthin (synthetic or algae) in feed on reproduction efficiency of rainbow trout and some indices of egg quality. Therefore, it was considered 7 groups consisting 6 treatments of two different astaxanthin sources and a control (without astaxanthin). So, algal astaxanthin (haematococcus pluvialis) in the three levels of 2.67, 3.55 and 8gr/kg food (T1,T2, T3) and synthetic source in three levels of 40, 80 and 120mg/kg food in diet (T4, T5, T6) examined on 140 trout broods (3-4 years) for 4 months, before the spawning season. Reproduction efficiency analyzed through reproduction indices such as egg diameter, fecundity, fertilization, survival, hatching and eyed egg rates. Significant difference between treatments in terms of fecundity, eyed eggs rate and the number of eggs per gram was observed (P 〈0.05). Although in some factors such as diameter, egg weight per body and fertilization rate, no significant differences was observed. By increasing level of astaxanthin in both sources of algal and synthetic, hatching and eyed egg rates increased, but the effect of alga source on these indices was more perfect. Considering the results, the best result related to treatment of 8 gr/kg alga (T3). Observations during this research indicated no disease and mortality and also proper coloration and freshness of fishes. There was significant differences on blood factors (P 〈0.05). The broods were fed with algal astaxanthin had lower blood sugar. concentration of cholesterol was decressed alog with increasing in both the source of astaxanthin, however lower cholesterol relaed to algal astaxanthin. Total serum protein increased in treatments containing algal from 2.67 to 8 g/kg of astaxanthin. Increase in level of astaxanthin from 40 to 80 mg/kg, albumin increased and from 80 to 120 mg/kg, it was decreased. The changes in serum globulin treatments containing synthetic was not regular. Overall the results asserted that the application of astaxanthin improves reproduction performance of rainbow trout. It also concluded that natural astaxanthin (Haematococcus pluvialis) for the reason that contains supplementary nutritious, is extraordinary preferable than synthetic astaxanthin to improve reproductions indices and egg quality of rainbow trout.

Description: Iranian Fisheries Science Research Institute

Description: Published

Description: In recent years, aquatic diseases have damaged aquaculture industry in different areas of the world. Although tilapias are known as resistant fish against different pathogens, but there are some reports about infectious diseases of tilapia. Tilapia aquaculture in Iran is in the beginning stage. So, planning for hygiene observations and preventing of disease prevalence must be considered. Tilapia hatchery and indoor systems of National Research Center of Saline water Aquatics were monitored for infectious disease from October 2012 to February 2014. Unusual locomotion/feeding or uncommon signs in the shape or body surface of cultured tilapias, fries and eggs or exceed mortalities were mentioned for bacterial, fungal, parasitic or viral pathogens. Infectious agents in this study were bacteria Streptococcus and Edwardsiella, the fungi Penicillium and Aspergillus and parasitic monogeneans Gyrodactylus and Dactylogyrus. No viral agent was diagnosed. Although recorded pathogens were rarely observed during the study but much attention must be paid for hygiene monitoring and instruction performance.

Description: Iranian Fisheries Science Research Institute

Description: Published