m.j. zorriehzahra

Cyprinid herpes virus 3 (CyHV-3) is a significant threat to the production of common carp and koi, resulting in high mortality rates and posing a risk to the long-term sustainability of carp aquaculture. The presence of this disease in Iran has been confirmed by the veterinary organization and reported to OIE, with evidence suggesting its presence since 2021 in Iranian Koi and carp farms. Given the economic importance and rapid spread of CyHV-3, this review aims to provide a comprehensive summary of the current knowledge and research on the virus and its disease in Iran and worldwide.  The fish farmers and authorities in the country need to take necessary measures to prevent the spread of the disease and mitigate its impact on the aquaculture industry.

Vaccination is considered the most effective, environmentally friendly and cost-effective way of protecting commercial finfish species against infectious diseases with high economic impacts. Efficacy of a new inactivated VNN vaccine through heat-inactivated nervous necrosis virus (NNV) combined with three types of adjuvants was assessed in 7 g juvenile of Acipenser stellatus Pallas, 1771 as a laboratory model. Ten groups of 30 numerical were considered in 18 aquariums using both immersion and injection routes in the form of 4 types of vaccines.Vaccination was performed in two stages one month apart, and one month after the second replication, exposure to the 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. Sampling was performed in four stages before the first vaccination in the adaptation period, after the first vaccination, after the second replication and after exposure to live virus. Blood samples were measured to evaluate changes in blood factors (red blood cell count, white blood cell count, hematocrit and hemoglobin) and immunity factors (immunoglobulin, superoxide dismutase, lysozyme).In order to prove the virulence of the viral sample (supernatant) used in exposure, the pathogenicity of VNN virus isolated from infected Caspian Sea mullet with (TCID50 ) was examined in several guppies. One month after the second repetition of fish, all treatments were exposed to the acute virus sample (supernatant) and after one month, their survival percentage, blood factors and safety were measured.The results of this study showed that immersion vaccination in the vaccinated group containing IMS 1312 SEPPIC adjuvant significantly showed higher levels of IgM compared to other groups equal to 0/35   (P<0.05). This is consistent with the results of hemoglobin 40.6  (P<0.05), which proves the better efficacy of this type of vaccine compared to other vaccines tested in this study.Based on the results of this study, a vaccine killed with 75% IMS 1312 SEPPIC adjuvant can be recommended for vaccination against VNN.

Viral Nervous Necrosis (VNN), caused by betabodavirus, is considered as one of the most important threats for mariculture and aquaculture globally. The disease was previously reported in wild golden grey mullet (Chelon aurata) from the Caspian Sea in 2004. To update these findings and to examine the phylogenetic relationship of the betanodavirus involved in disease outbreaks in Iran with other betanodavirus genotypes, forty golden grey mullets were screened for the presence of betanodavirus using real-time RT-PCR targeting the T4 region of RNA2 coat protein gene. The results showed that all 40 fish has positive test for the virus, which was also confirmed by immunohistochemistry. The phylogenetic relationship of betanodavirus involved in disease outbreaks in Iran from 2016 to 2017 was compared with betanodavirus genotypes sequenced from elsewhere, and the 300 bp product from the real-time RT-PCR sequenced was found to have a 98–100% homology with red-spotted grouper nervous necrosis virus (RGNVV), confirming that the betanodavirus detected in wild golden grey mullet in the southern parts of the Caspian Sea adjacent to Iran determined to be the RGNNV genotype.

This study was carried out to investigate the effect of dietary supplementation of garlic (Allium sativum) extract on growth parameters and hematological parameters and immune system response of Mugil cephalus larvae encountered with Photobacterium damselae. Two hundred and forty M. cephalus larvae with a mean weight of 5g were randomly divided into 12 equal groups, each containing 3 replicates. Fish were fed with diets containing 50, 100 and 200mg garlic extract/Kg of food for 8 weeks. Based on the results, significant difference was observed comparing final weight, specific growth rate (SGR), daily growth rate (DGR), protein efficiency ratio (PER) and feed conversion ratio (FCR) of 100 and 200mg garlic extract/Kg of food treatments and other treatments (p<0.05). Also, in 100 mg garlic extract/Kg treatment, red and white blood cells, hemoglobin, PCV counts, globulin, total protein and albumin were significantly higher than those of control and 200mg garlic extract/Kg of food (p<0.05). The immune indices (lysozyme activity, serum total immunoglobulin (Ig) content, phagocytic activity and respiratory burst activity) significantly increased in 100mg garlic extract/Kg treatment compared to those of other treatments, especially control (p<0.05). The results revealed that treatments containing 50 and 100mg garlic extract/Kg food had the highest survival after challenging with P. damselae compared to survival of other treatments (p<0.05). In conclusion, results suggested that dietary administration of garlic extract; especially in 100mg garlic extract/Kg concentration is recommended for enhancing growth performance, nutritional function, immunity and resistance of M. cephalus larvae against the bacterium P. damselae.

The novel pandemic disease has been evaluated as a global health emergency by the World Health Organization (WHO) due to its rapid spread worldwide. In many countries, the established restrictive measures on the movement and travel have had adverse economic outcomes, including a substantial drop in both jobs and salaries, in these communities. The economic consequences of the COVID-19 have severely affected the aquatic food supply chain, i.e. the fishers, aquaculture farmers, processing, and marketing sector due to the decrease in consumer purchasing power. There is increasing evidence that the farmers are not able to sell their products which lead to the live fish stocks increasing and therefore higher costs for feeding. In contrast, a fall in demand and selling price of aquatic food has resulted in a decline in fishing activities, which may give wild fish stocks a chance to recover. This review aims to summarize the impacts of the novel coronavirus disease (COVID-19) on aquatic food production.

The aim of this study was to identify different virulence pathogens using Real-Time PCR method for rapid and accurate detection of common viral diseases including Infectious Hematopoietic Necrosis (IHN), Viral Hemorrhagic Septicemia (VHS) and Infectious Pancreatic Necrosis disease (IPN) in rainbow trout broodstock have been the main generation of reproductive populations maintained in the national plan for production the Specific Pathogen Free (SPF) fish. For this purpose, sampling was carried out on selected farms approved by the National Veterinary Organization in the provinces of Mazandaran, Kohgiluyeh and Boyerahmad and West Azerbaijan. Sampling of fish was done in different age groups and organs and was immediately frozen in liquid nitrogen. RNA extraction and Real-Time PCR experiments were performed using primers for the diseases. The results obtained using Real-Time PCR testing of healthy and suspected viral fishes showed the presence of VHS and IHN viruses in a number of selected farms, while the pathogenic virus IPN not detected. Based on the results of this study, it seems that Real-Time PCR can be used as a rapid diagnostic method in screening tests for rainbow trout viruses and as a complementary method for virus detection in routine tissue culture experiments.

This study aimed to identify the chemical composition of essential oil of some Iranian medicinal plants and their antifungal activity against Saprolegnia parasitica in comparison to formalin as positive control under in vitro conditions. The essential oils of Eryngium campestre, Pimpinella affinis, Mentha piperita, Achillea wilhelmsii and Cuminum cyminum were analyzed for their activity by disk diffusion, Minimum Inhibitory Concentration (MIC) and Minimum Fungicidal Concentration (MFC) methods. Also, the oil constituents of investigated plants were analyzed by gas chromatography/mass spectrometry (GC/MS). The major constituent of the surveyed essential oils was bornyl acetate (17.9%) in E. campestre, Pregeijene (27.3%) in P. affinis, menthol (48.5%) in M. piperita, 1,8-cineol (25.2%) in A. wilhelmsii, and α-Pinene (29.1%) in C. cyminum. The MIC values for the surveyed essential oil were was 0.5 µg ml-1 for C. cyminum followed by M piperita and E. campestre both having 1 µg ml-1, for P. affinis 2 µg ml-1 and was 4 µg/mL for A. wilhelmsii. The MFC for the mentioned essential oil were with 0.5 µg ml-1 again lowest for C. cyminum, followed by M. piperita and E. campestre with 2 µg ml-1, for P. affinis MFC was 4 µg ml-1 while it was with 8 µg ml-1 highest for essential oils from A. wilhelmsii. The results indicate that the essential oils of C. cyminun, E. campestre and M. piperita could be potential candidates for new plant based antifungal components in aquaculture against S. parasitica.

Anesthetic agents are used in fish to decrease stress and mortality during sorting, surgery, diagnosis and artificial fertilization procedure. This study was done to evaluate and compare the efficacy of propofol and clove oil for anesthetizing Capoeta damascina. For this purpose, 40 fish were caught from Arvand River and divided into two groups. After a pilot study, propofol and clove oil were examined in 12.5 mg L-1 and 125 mg L-1 concentrations, respectively. The onset of anesthesia, duration period of anesthesia and recovery time were recorded separately for each group and compared. Results showed that the anesthesia onset of specimens in propofol treatment, was significantly shorter than that of clove oil treatment (p<0.05). Also, recovery time in propofol treatment was longer (p<0.05) than that of clove oil. Based on the results, it was recommended to use propofol instead of clove oil in performing anesthesia for this species due to rapid induction, longer duration and more prolonged effect in immersion method.

The isolation of Aeromonas hydrophila from Oncorhynchus mykiss reared in the farms was the aim of the present study. Ninety samples were collected aseptically from the infected fish with signs of hemorrhagic septicemia in gill and skin, exophthalmia, dropsy and 36 water samples were sub-cultured on Tryptic Soya Agar (TSA), as well as kidney. The genotyping by PCR method was used to amplify the gene of 16 SrDNA using primers 27F and 1492R as primer pairs to achieve an approximate length of 1500 bp. The identified motile Aeromonas species were sequenced with electrogram chromas format in chrome version 1/41 software and a phylogenetic tree was drowned by MEGA5.1 software. The results showed that 19% of 24 isolated from gram-negative bacteria were detected as Aeromonas, which the sequencing results revealed that all the isolated bacteria had 99% similarities with the standard A. hydrophila. The results of environmental factors showed when the levels of dissolved oxygen have decreased and the levels of nitrite and ammonia have increased throughout the year, Aeromonasias is increased. Also, when the water has gone alkaline due to increased ammonia, the disease has increased. It may be concluded that fish farmers should take proper management practices to avoid such disease in cultured fishes especially rainbow trout and to get rid of the infection by such serious bacterial pathogen like Aeromonas hydrophila by improving their culture strategy and culture ecosystem.

This study was undertaken to investigate the diversity, abundance ratio, and distribution of the fish species and to record the water quality of Konhaye Stream, district Dir Lower, Pakistan. A total of 16 fish species were recorded, belonging to 4 orders (Cypriniformes, Channiformes, Siluriformes and Mastacebilformes), and 5 families including Cyprinidae (Schizopyge esocinus, Racoma labiata, Cyprinion watsoni, Cyprinus carpio, Barilius pakistanicus, B. vagra, B. modestus, Crossocheilus diplocheilus, Garra gotyla, Puntius ticto, and P. sophore), Channidae (Channa punctatus and Channa gachua), Nemacheilidae (Schistura macrolepis), Sisoidae (Glyptothorax punjabensis), and Mastacembelidae (Mastacembelus armatus). Different ichthyo-diversity indices [Simpson’s biodiversity index (D=0.918), Simpson’s reciprocal index (1/D=1.088), Simpson’s evenness index (E1/D=0.068), species richness (S), Shannon-Weiner’s index (H′=3.775), Menhinick’s index (Dmn=0.804), and Margalef’s index (Dmg=2.510)] were calculated for the stream. The physicochemical parameters [temperature (23.125±3.514℃), dissolved Oxygen (9.003±0.627 mg L-1), pH (7.333±0.201), turbidity (76.5±6.403 NTU), electric conductivity (201.68±11.31 µs cm-1), free CO2 (124.75±9.912 ppm), total dissolved solids (126.1±9.477 ppm), total alkalinity (4.325±0.171 mg L-1), total suspended solids (127.1±6.864 ppm), total hardness (5.225±0.341 mg L-1), salinity (42.25±6.292 ppt), calcium hardness (2.975±0.670 mg L-1), magnesium hardness (105±9.954 mg L-1), potassium (0.0145±0.001 mg L-1), sodium (16.55±3.861 mg L-1), chloride (1.825±0.727 mg/l), and nitrate (0.053±0.006 mg L-1) level] were monitored and found to be in varying but permissible ranges. The stream was found to be harboring a number of economically valuable fish species. An exotic fish species, C. carpio, was found well flourished, indicating the potential of the stream to be used for mitigating the declining ichthyofaunal diversity in the main nearby rivers. Two species, P. sophore and P. ticto, were recorded for the first time from the district. Proper management, appropriate fish stocking, and implementing environmental/fishing laws are suggested for the maintenance of the diversity and alleviating anthropogenic stress/threats.

The Persian Gulf and its shores are important and strategic areas with a large variety of fish species. Betanodavirus infection is known to be a serious threat to susceptible fish and causing economic damages to the fisheries and fishing industry. Concerning to isolation and confirmation of VNN virus in the Mullet fish (Chelon aurata and C. saliens) in the Caspian Sea and its damages on Mullet stock, probably transmission of VNN could be hazardous in marine fish industry such as cage culture. So, the aim of this article was to characterize the distribution of the Betanodavirus in Iranian southern waters and its transmission. Finally, the issues of the transmission of Betanodavirus infection between the wild and farmed fish of different regions of the Persian Gulf is discussed. The probability of the emergence of viral epidemics and even new and virus-resistant hosts has been investigated whereby the monitoring and surveillance program for tracing the disease and the detection of the Betanodavirus presence is required before clinical signs occur in the near future. Meanwhile, screening of various species of susceptible fish and the identification of the viral carriers as a strategic approach is recommended. In fact, Eco- epidemiological studies are needed and all efforts should be focused on control and prevention of probably virus contamination in the Persian Gulf and Oman Sea waters as one of the strategic points in the world.

This study evaluated the influence of dietary garlic (Allium sativum) extract on survival rate and changes in blood and immune parameters of Common carp (Cyprinus carpio), fed with two different concentrations of aqueous garlic extract after exposure to spring viremia of carp virus (SVCV). The experiments have executed in two steps: Firstly, 270 fingerlings of Common carp with an average weight of 15±3.4 g have cultivated in 18 aquaria with 15 liters of water. Fish were fed with 1 and 5 g garlic extract kg-1 basal diet for 8 weeks. In the second step, 240 fingerlings have been randomly divided into 8 groups (A: negative control; B: virus control; C and D: extract controls and E-H: treatment groups) with 3 replicates in each group include of 10 fish in each replicate, and the fish have been exposed to SVCV for 4 weeks. The mortality rate, blood and immune parameters and virus isolation have been determined at the end of experiments. The results have showed that the survival rate of the Common carp fed with 1 and 5 g garlic extract kg-1 basal diet (E-H groups) had a significant increase compared to the control groups (p<0.05) and RBC, hemoglobin, hematocrit, MCH, MCHC had Significant increase compared to the virus control group (B) (p<0.05). WBC in groups D, E, F and G in comparison to control group A and B and lymphocyte in groups D, E and F compared to control group B had a Significant increase (p<0.05). Also, the Common carp fed with two concentrations of garlic extract increased lysozyme and IgM in groups C-H compared to group A (p<0.05). Finally, cell culture and RT-PCR have been applied for detection of SVC virus from fish samples. The results have been indicated that addition of garlic extract (Especially 5 g kg-1) in fish dietary has led to a higher immunity and survival rate of common carp exposed to SVCV.