جستجوی مقالات مرتبط با کلیدواژه « s » در نشریات گروه « شیلات »

Age, growth, and reproductive traits of the South Caspian Spirlin in the southern part of the Caspian Sea basin, Tajan, River, were investigated. A comprehensive study was conducted on 663 specimens including 226 females, 297 males, and 140 unsexed individuals with a total length ranging from 25.88 to 121.66 mm. The specimens were collected using an electrofisher at monthly intervals. The female-to-male sex ratio was calculated as 1: 1.29. The growth rings on the scale were employed for age determination in this study. Both sexes exhibited only four age groups (0+ to 3+), with the 2+ age group dominating the population. Females consistently displayed larger sizes compared to males. The von Bertalanffy growth function yielded L t =123.90 (1- e -0.25(t+0.87) )  and L t =128.10 1- e -0.29 t+0.69  for males and females, respectively. Furthermore, the Fulton condition factor value was significantly higher in females than males. Notably, the maximum gonadosomatic index for both males and females coincided with the spawning seasons (May to August). Absolute fecundity varied from 290 to 1710 oocytes, with a mean of 793 oocytes. This study presents comprehensive data on the biological characteristics of the South Caspian Spirlin, providing valuable insights for fish stock assessment studies.

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.

Yersinia enterocolitica is the cause of yersiniosis in humans and its symptoms range from mild diarrhea to mesenteric lymphadenitis that may lead to appendicitis. In this study, the frequency and antibiotic resistance of Yersinia enterocolitica isolated from fish caught in Anzali wetland were investigated. Sampling was carried out for one year in four seasons from the autumn 2018 to the summer 2019 from four geographical directions: east, west, north and south, from different wetland levels. A total number of 91 fish were sampled from the body of these fish. Microbiological tests including biochemical tests, specific culture, and PCR were performed. In the specific culture method, 20 samples (21.97%) were contaminated with Yersinia enterocolitica. For the final confirmation of PCR, 20 samples were isolated from 14 samples (15.4%) containing specific culture method (6 Carp, 3 Anchovy, 0 Bream, 4 Pike Perch and 1 Pike) were infected with Yersinia enterocolitica. The chi-square test showed that there was no statistically significant difference between the various seasons (p >0.05), while there was a significant difference between fish species (p <0.05). Isolates from Yersinia enterocolitica using an antibiogram test of 10 antibiotics, the most susceptible isolates, Imipenem (92.8%), Kanamycin and Gentamicin (85.7%), Ceftazidime (78.57%). Cotrimoxazole and Nalidixic acid (71.4%) were the most resistant isolates to Ampicillin (64.28%), respectively. The results showed high levels of contamination of Yersinia enterocolitica, and indicative of potential dangers of Yersinia enterocolitica pathogenicity, especially in immunocompromised and susceptible individuals. Further studies on the pathogenicity of Yersinia enterocolitica in fish within the Anzali wetland and preventing sewage from entering the wetland are suggested.

Plastic pollution has emerged as a pervasive global concern, with plastic waste contributing to the generation of microplastic particles (MPs) that have now integrated seamlessly into the human food chain. Intriguingly, early life exposure to MPs in children may occur through breast milk. This preliminary involved the analysis of human breast milk samples collected from 15 healthy breastfeeding mothers of the fishing community (BMSF) with daily habits of sea-food consumption and 8 healthy breastfeeding mothers (BMSH) with no history of seafood consumption in the past month and analyzed using microscopy and micro-Fourier-transformed infrared spectroscopy. In the BMSF group, a total of 276 MPs while 49 MPs were found in the BMSH group, indicating a substantial difference in MPs presence. The most prevalent MPs in both groups were fibers and pellets which fell within the size range of 5 to 18 µm, with polyethylene, polyvinyl chloride, and polypropylene being the most frequently observed types. Statistical analysis revealed a significant difference in the abundance of MPs between the two communities (F=13.57, P=0.001; Mann-Whitney U test, p<0.05). These findings emphasize the urgent need for further research to explore the potential health implications of MPs exposure through breast milk, especially in economically disadvantaged and vulnerable communities’ i.e. pregnant women, lactating mothers and children, with high seafood consumption.

Caulerpa racemosa is edible marine green algae of the Caulerpaceae family. C. racemosa is consumed as a sea vegetable in many countries, especially Southeast Asian countries. In recent years, molecular studies caused some changes in the taxonomic positions of the members of the genus Caulerpa. It is necessary to accurately identify species of this genus based on modern molecular studies due to the consumption of some species and also the toxic effect of some other species of this genus. Some species of Caulerpa have already been reported from the southern coasts of Iran based on preliminary morphological studies. The purpose of this study was to collect and accurately identify the species of the genus Caulerpa in the coastal waters of the Persian Gulf and the Gulf of Oman in the southern coastlines of Iran. This study was based on the combination of molecular and morphological characteristics studies of the collected samples of this genus in this area. In the current article, the results obtained about the Caulerpa racemosa are presented. Samples of the genus were collected from different coastal areas of the Persian Gulf and seashores of Oman Gulf along the geographical borders of Iran and transported to the laboratory in cool conditions. After cleaning and washing, some of the cleaned samples were dried in silica gel and used for DNA extraction and thereof PCR process based on tufA gene. In addition, herbarium samples required for morphological studies were prepared and deposited in the herbarium of Agriculture and Natural Resources Research and Education Center of Hormozgan province. The results of this study relatively solve the confusion in Caulerpa racemosa- peltata complexity for Iranian members of the complex. In addition to morphological features, the current molecular investigation also helped to accurately identification of the members of this complex in the Iranian seashores of the Persian Gulf and Gulf of Oman. As a highlighted conclusion, the current research on Caulerpa species from the Iranian seashores of the Persian Gulf and Gulf of Oman resulted in resolving two species including Caulerpa sertulariodes (S. G. Gmelin) Howe forma farlowii (Weber-Van Bosse) Børgesen, which was resolved as Caulerpa selago (Turner) C. Agardh (Salehi Balashahri et al., 2021) and Caulerpa racemosa var. macrophysa also resolved as Caulerpa racemosa (Forsskål) J. Agardh.

It is well known that ammonia nitrogen is a major pollutant in aquaculture, which can have toxic effects on fish. When absorbed in toxic concentrations, ammonia nitrogen can enter the bloodstream of fish, affecting blood parameters, immune responses, and causing oxidative damage and neurotoxicity. Recently, a study was conducted to investigate the toxic effects of ammonia on the blood, liver, growth, tissue damage, and immune indices of Cyprinus rubrofuscus in the presence of formaldehyde bisulfite sodium (FBS). The study involved 360 C. rubrofuscus, which were randomly distributed among 24 aquaria with a ratio of FBS to ammonia set at 31mg/L:1mg/L. The experiment was conducted with 15 fish in 6 treatments and 4 repetitions until 50% mortality was observed. The growth, histology, hematology, immunity, liver enzymatic and biochemical features of the fish were studied, and the results were analyzed using one-way analysis of variance (One-Way ANOVA) and Duncan’s test. The study found that the blood, immune, and liver indices of koi fish changed in the presence of FBS. Additionally, adding FBS to aquarium water reduced nitrogen compounds in fish storage tanks, further reducing the nitrogen compounds in fish aquaria.

The  present  study  was  conducted  to  evaluate  the  dietary  effect  of  nucleotide  on  growth performance and intestinal microbial flora in Siberian sturgeon (Acipenser baerii). Four hundred fifty fish of A. baerii (39.77±10.24 g initial weight) were distributed into 15 tanks (300 L) and they were fed with different levels of nucleotide (Ascogen®) including 0.0 (control), 0.2 (diet 1), 0.4 (diet 2), 0.6 (diet 3), and 0.8 (diet 4) g kg -1 in triplicates for nine weeks. The fish were fed daily until apparent satiety. The results showed no significant differences in the final length and survival rate among the experimental groups (p>0.05). However, the final weight, weight gain, daily growth rate, specific growth rate, and condition factor were significantly enhanced in the groups fed with diet 3 and diet 4 (p<0.05). The count of intestinal lactic acid bacteria (LAB) was the same among the experimental groups (p>0.05), while the total count of the intestinal bacteria was significantly decreased compared to the control group (free from nucleotide) (p<0.05). In conclusion, most of the growth indices were improved in the fish fed with nucleotide at 0.6 and 0.8 g kg -1. However, the treated diets could not affect the intestinal LAB population in Siberian sturgeon.

Aquaculture represents a pivotal economic sector worldwide, meeting the escalating food demands of the expanding global population. Consequently, this research aimed to assess the incidence of fatty liver in Asian sea bass (Lates calcarifer) subjected to a diet enriched with lactic acid bacteria and evaluate their survival against Streptococcus iniae infection. The present study examined 240 sea bass (109 ± 10.5 g average weight) that were randomly assigned into four treatments with three replicates (25 specimens per treatment) for 60 days. The treatments comprised the following: First treatment: fish were fed with commercial feed. Second treatment: fish were provided with feed containing 109 CFU/g of Lactobacillus plantarum bacteria. Third treatment: fish were fed with feed containing 109 CFU/g of Lactobacillus pentosus bacteria. Fourth treatment: fish were provided with feed having 109 CFU/g of L. pentosus bacteria combined with L. plantarum in equal proportions. At the end of the experiment, the growth performance, the survival rate against the pathogenic bacteria S. iniae and the amount of fatty liver were evaluated. The findings disclosed enhanced growth indicators in the second treatment (strain 140) during the initial 30 days. Furthermore, statistically significant disparities were noted in the third treatment (2P) concerning PER, SGR, WG, RGR, and DWG during the subsequent 30-day period (P<0.05). Liver pathology examination demonstrated that most treatments resulted in the development of fatty liver. However, the third treatment (L. pentosus) exhibited the lowest incidence of fatty liver when endogenous probiotics were incorporated into the diet. Post-challenge with S. iniae, the mortality rate in the probiotic treatments L. pentosus (P2) and L. plantarum (140) significantly surpassed that of the control group (P<0.05). The findings underscore the absence of synergistic interactions between the two experimental probiotics on the 60th day, as the combined group displayed diminished growth performance compared to the individual groups. Moreover, the use of L. plantarum and L. pentosus bacteria, particularly the latter, has been shown to significantly improve several growth indicators, as well as the food conversion ratio. Consequently, these probiotics are recommended as dietary supplements for Asian sea bass.

European anchovy (Engraulis encrasicolus) is one of the most important commercial species in the Mediterranean Sea. 4310 studied records were reported from the Google Scholar database between 1980 and 2022. A search with the keywords "Engraulis encrasicolus" or "European anchovy" and "growth" and "sex" and "length" and "length-weight relationship" returned 201 results, of which only research articles were included in the compilation. A total of 20 studies were evaluated in the present study. In the studies on the growth and length-weight relationship of anchovy species, pooled random effect meta-analysis, subgroup analysis, and moderator analysis were carried out. It was found that sex had a significant effect on the mean and standard deviation of length of male and female individuals. The results showed that there was a positive correlation between male and female individuals. The moderator analysis was carried out to examine this high heterogeneity. Accordingly, L∞ and K values and b coefficients of male and female individuals in different regions of the Mediterranean Sea should not be considered equivalent. The results of the study are generalizable to the reviewed studies except for the b coefficients of males and females.

Nepal has a diverse geography, ranging from an altitude of 60 m to the world's highest peaks at 8849 m. Fish diversity has been observed to extend up to an elevation of 3600 m. With its intricate topography, fluctuating climatic conditions, and abundant water resources, the region exclusively comprises freshwater habitats spanning 745,000 ha. These habitats include rivers, lakes, ponds, marshes, reservoirs, and irrigated rice fields. There are roughly 6,000 rivers and creeks in the country (194,471 km² drainage area). Four major river systems, namely Koshi, Gandaki, Karnali, and Mahakali, originate from the upper Himalayas at an altitude greater than 5000 m above sea level and drain about 75% of the country. Freshwater fishes are often overlooked in biodiversity conservation efforts, leading to a significant decrease in fish diversity, particularly in densely populated urban areas and wetlands in the southern plains of Nepal. The decrease in fish diversity is likely linked to inadequate prioritization, funding, and human resources allocated to fish conservation. According to the literature and FishBase database records, the freshwater river system in Nepal contains a total of 255 fish species from 12 orders, 41 families, and 124 genera. This includes 15 fish species that are unique to Nepal and 15 that are not native to the region. Additionally, 34 fish species in this system are considered threatened and have been listed under the IUCN Red List. These fish have pronounced vertical dispersion throughout the country and horizontal distribution within the area and continent, displaying diverse adaptations. This research specifically examines the fluctuations in water quality and the range of fish species, together with their conservation status in the rivers of Nepal.

Numerous techniques are used in aquaculture to stripped eggs from fish broodstocks. The most common is the manual method, where the abdomen of the fish is gently massaged to extract the eggs. Alternatively, injecting gas pressure into the abdominal cavity can facilitate the release of eggs with potentially fewer negative impacts on the welfare and egg quality. This study compared the pneumatic stripping methods and the manual spawning method in rainbow trout (Oncorhynchus mykiss) spawners. The study focused on the effects of these techniques on the quality of the harvested eggs, relative fertility, stripping duration, and pH of the ovarian fluids. The findings revealed that maintaining a gas flow rate at 1.5 L min-1 during stripping is crucial to prevent post-stripping mortality of the broodstocks. The pneumatic method demonstrated a shorter duration of egg retrieval (39.5 s) compared to the manual method (42 s). Notably, there were no significant differences observed in ovarian fluid pH across the various methods (p<0.05). Overall, pneumatic egg extraction leads to higher-quality eggs with a greater hatching rate compared to the manual method. Considering the positive results of the pneumatic stripping and its high level of repeatability and efficiency, it can be used instead of the traditional method in rainbow trout hatcheries.

The main purpose of this research was to design a model that meets the educational needs of Iranian fisheries researchers in developing fisheries entrepreneurship ecosystems. In this research, educational needs were identified using a mixed research approach (qualitative-quantitative). In the first stage, semi-structured interviews and grounded theory were used to develop a model of fisheries researchers entrepreneurship education. The results indicated that casual conditions include coordination and communication challenges, applied research needed by the private sector, teaching general entrepreneurship skills, background conditions including the personal characteristics of researchers, the difficulties of carrying out organizational and research activities and financing challenges were intervening conditions. Supporting commercialization and establishing business acceleration centers, and presenting commercialization models as part of strategic conditions, promoting sustainable production and harvest, and recognizing the advantages of knowledge and income for researchers were identified as the positive effects of entrepreneurship education on Iranian fisheries researchers in the development of fisheries entrepreneurship ecosystems. In the quantitative section a questionnaire was compiled and given to a statistical sample which included researchers and faculty members of the Iranian Fisheries  Science Research Institute, Sampling was done through Cochran's formula (n=135). The identification of educational need items was accomplished through the employment of confirmatory factor analysis. Educational needs were categorized into seven components consist of 1) management and planning of applied research projects, 2) startup and entrepreneurship, 3) communication, 4) teamwork and networking, 5) fisheries Innovation ecosystem, 6) extension activities, principles and 7) rules and commercialization.