جستجوی مقالات مرتبط با کلیدواژه « ماهیان دریایی » در نشریات گروه « شیلات »

Betanodavirus is a very dangerous and acute infection in various species of fish, especially fish with economic value. The causative agent of this disease is from the Nodaviridae family. According to the conducted studies, more than 40 species of fish have been reported to be infected with viral neuronecrosis. Aquaculturists and fisheries experts believe that the disease caused by Betanovirus infection affects mostly marine fish, and in addition, it affects mostly larvae or young fish. Symptoms of betanodavirus include exophthalmia, anorexia, swelling of the swim bladder and whirling swimming of fish. However, many researchers stated that the central nervous system of fish is severely affected by beta-novirus infection, and the key symptoms of this viral infection are vacuolation of the spinal cord and brain. Viral neuronecrosis often spreads through horizontal transmission, but vertical transmission is also possible. So far, many efforts have been made by biologists and veterinarians around the world in order to control betanodavirus diseases. This research has shown that the implementation of health measures along with vaccination is a useful way to control betanodavirus disease in aquaculture industry. According to the findings of this study, the discovery of new vaccines with special potentials along with increasing the strength of the immune system of fishes using bioactive compounds including medicinal plants are acceptable ways to control betanodavirus disease in Iran's aquaculture industry.

In the present study, the effects of different probiotics mixtures on growth performance, hematology and antioxidant capacity of Asian seabass (Lates calcarifer) juveniles (30 g). In this study, three bacterial mixtures were used that were isolated from the native aquatic species of Khuzestan and the South of the country, which include: the first group includes different strains of Lactobacillus plantarum, the second group includes L. plantarum with a mixture of L. bulgaricus, L. acidophilus and L. rahamnosus and the third group includes the mixture of bacteria of the first and second groups along with the mixture of Bacillus cereus and B. thuringiensis, which were identified through their quorum quenching features and isolated from Asian sea bass. Four treatments were designed by spraying various bacterial mixture on a basal diet, which included diet (1, control group) on which only sterile physiological serum was sprayed on the diet, diet (2) on which the bacterial mixture of the first group was sprayed on the diet, diet (3) on which the mixture of bacteria of the second group was sprayed and diet (4) which was the mixture of all bacteria was sprayed on it and fed to the fish. The fish was fed with the experimental diets four times a day up to satiation at 30.5 °C for 100 days. In this study, the fish that was fed with 2, 3 and 4 diets had a higher growth performance than the control (p < 0.05), which was associated with an improvement in the food conversion ratio. Blood and antioxidant indices were improved in the fish fed with diets containing probiotics mixture. Treatment 4 had more total plasma protein and albumin than other treatments. In conclusion, the use of a mixture of different probiotics increased growth in Asian seabass that associated with improved health indices in this species.

Despite the reported effects of egg vitellogenin-derived proteins (VtgDP) and amino acids on embryo-larvae viability in common dentex the effects of non-vitellogenin-derived proteins (non-Vtg-DP) has yet to be determined. As an initial study, fertilized eggs (70 batches) were provided by natural spawning of broodfish in captivity. Viability parameters (VP) such as egg floating, hatching, and larval survival rate were calculated. Egg batches were categorized as low, medium, and high quality upon hatching rate. Based on the SDS-PAGE of egg crude extracts 63 protein bands (16.7 to 131.4 kDa) were identified. The intensity of bands on gel (densitometry; <200 to 877 μg mL-1), and their biochemical nature (specific staining) was determined. After subjecting the bands to a screening process, 11 bands were considered as non-vtgDP-contained bands. The highest intensity of the bands was observed in the gels belonging to high quality eggs. The intensity of 9 bands of 11 (individually or in combination with other protein bands) was significantly (p<0.001) and positively correlated to VPs via a series of simple and multiple regression models. In brief, the preliminary results revealed the importance of the class of egg proteins and their effects (individual and combined) on the viability of common dentex larvae and indicated their probable potential use to predict egg quality in teleosts. It also showed that it is worth to conduct a deeper study for more detailed characterization of the protein content of the selected bands and to evaluate the mechanism of their effects on larval success

Although fisheries production has increased dramatically over the last decades, the waste portion (such as skin, bones, intestines, and viscera) accounts for a significant part of yield. Marine fish are known as a rich source of bioactive compounds such as bioactive peptides. Recently, marine fish-derived peptides have obtained especial interest. The market size of fish protein hydrolysates is expected to grow of 4.5% between 2020 and 2026. Extraction of bioactive peptides is done by acid-alkaline hydrolysis, enzymatic hydrolysis and fermentation and depending on the structure and sequence of amino acids obtained, they have suitable biological properties suitable for the cosmetic-pharmaceutical industry. Furthermore, the production of marine bioactive peptides not only reduces environmental problems but also generates added value. The present article reviews the enzymatic hydrolysis and evaluated antimicrobial, antioxidant and anti-photoaging effects of peptides extracted from marine fish.

Lactoferrin is an iron ion-binding glycoprotein belonging to the transferrin family, which is present in varying amounts in the milk of mammals, including cows. This glycoprotein was first isolated from cow's milk and was identified as milk red protein due to its iron content. Lactoferrin is considered an important host defense molecule and has a wide range of biological functions including a role in iron metabolism, cell proliferation and differentiation, and antibacterial, antiviral, and antiparasitic activity. One of the most important properties of lactoferrin is the iron absorption and transport. By absorbing free iron, lactoferrin deprives the environment of this element and thus deprives it of the pathogens that it needs to survive, thereby indirectly inhibiting the spread of infection by inhibiting the growth of harmful bacteria. The results show that although the use of lactoferrin in the culture of some species such as yellowfin seabream (Acanthopagrus latus) and Japonica eel (Anguilla japonica) has increased the growth and immune performance but use in the diet of some species such as sobaity fish (Sparidentex hasta) had different results (positive effect and no effect). Therefore, it seems that results will be varied for every species and different experimental conditions and more research is needed in this field.

Despite the great benefits of aquatic to the health of the society and its good production capacity in Iran, the per capita consumption of this meat is lower compared to the other meats in the household food basket. The present research studied the factors affecting the selection of high- consumption marine fish in Bandar Abbas. The required data including the characteristics of consumed marine fishes, economic and demographic characteristics of households, were collected using a cluster random sample of 384 households in the summer of 1397. High-consumed fishes in the study area were classified into three groups based on their prices and characteristics, which are statistically significant according to the Kruskal-Wallis test. The mixed logit model was used to find the effect of economic and demographic characteristics on the selection of fish species. The results showed that with the increase in the level of education and income, the probability of choosing the first group increases by 8 and 62 percent, respectively. In other words, fishes with easy separable blades and more meat and better taste are selected. However their price is higher compared to the second and third groups. The latter two groups of fishes are consumed more often than the first group as they are cheaper. Given the nutritional value of fish and its role in consumer health, marketing promotional programs can lead the consumers to use the second and third groups of fishes more than the first group.

Biofouling are small and big creatures (such as barnacles, shellfish, and algae) which are attached in the cage farming industry on cages and creates many problems. These problems typically include increasing the weight of the net, reducing water flow, creating undesirable environmental conditions in the cage, increasing the risk of illness and managing problems. In general, many undesirable managerial processes, such as unsatisfactory food, inappropriate feeding time, inappropriate site selection, unstructured cages arrangement, inappropriate storage time and harvest, increase the effects of these creatures and production costs. There are many ways to reduce the effects of the presence of these creatures, including the use of anti-fouling, washing the nets, removal and drying of nets during sunshine and other methods. In general, with the consideration of some management factors and considering environmental conditions, the presence of these organisms can be reduced.

One of the principal problems in marine fish larval rearing which includes financial loss is related to increased mortality in the stage while larvae have to shift feeding on formulated from live food. The reasons for applying weaning are high production costs, increased bacterial load and unreliable nutritional value of live foods. The commercial dry feeds can address this concern and decrease the larval production costs and consequently generate a highly profitable investment. In this paper, it was tried to consider recommendation which helps the aquaculturists to pass this larval stage successfully. Attention to the larval development stage, larval behavior, feeding strategies and considering the factors such as effective health management and monitoring the environmental conditions which affect the success of this change are met to discuss.

Control and preventing the spread of diseases in the farmed fish requires a regular monitoring, eradication or vaccination program. And in this respect, the serology as a monitoring and diagnostic tool can be very useful. In recent years, monoclonal antibodies have been considered a tool in immunological in immunological research. These anti-inflammatory drugs are highly specialized in epitopes and are prepared in large volumes. Due to their high purity, monoclonal antibodies act as standard chemical agents. They have been quickly being used in clinical diagnostic techniques since a lot of them are needed in the production of commercial kits. Like serology in other animals, serum testing in fish also requires the use of anti-antigens (anti-IgM). For the same reason, during the last decade, efforts have been made to produce anti-IgM antibodies for the production of monoclonal antibodies, suitable for each species of freshwater and marine fishes. Therefore, the production of these antibodies in the interior, in addition to the help and development of the rapid and accurate detection of marine fish diseases can lead to currency savings.

In result of Fresh water crisis and water depletion on the world, attention to marine aquaculture has been most in last decades.so many country in the world try to developed marine cage aquaculture but many diseases and mortality as well as economic losses of producers reports indicated that disease as important challenges of this sector in the future. The incidence of diseases in cage culture systems could be genetically, nutritionaly,environmentaly(Physico_ chemical parameter of water and industrial water pollution), Mechanical damage and infectious disease(parasite, bacteria, fungi and virus). Among bacteria vibrio harveyi, Tenacibaculum maritimum and streptoccosiss inai are the most important with significant economic losses. As well iridovirus and betanodavirus are two high potential disease incidence in marine fish aquaculture. Asian sea bass iridovirus disease is scale drop syndrome (SDS) and betanodavirus is viral nerves necrosis(VNN) are two important disease of Asian sea bass aquaculture. Given that in aquaculture, health management and diseases prevention are superior to treatment so in marine aquaculture especially in cage system, stocking of SPF Fry& Fingerling, vaccination or vaccine therapy, using probiotic& prebiotic instate of antibiotic therapy and chemical drug are mentioned.