https://jfst.modares.ac.ir/ Journal of Fisheries Science and Technology en daily 1 Fri, 22 May 2026 00:00:00 +0330 Fri, 22 May 2026 00:00:00 +0330 https://jfst.modares.ac.ir/article_28967.html In Siamese fighting fish (Betta splendens), males exhibit greater phenotypic appeal and higher economic value than females. One of the novel and eco-friendly approaches to achieve a male-dominated population and induce sex reversal is the use of plant extracts. This study investigated the efficacy of a combination of herbal extracts (Ginger, Tribulus and Ginseng) in inducing sex reversal in Betta splendens fry at dietary concentrations of zero (control), 150 (T1), 300 (T2) and 600 (T3) mg/kg of feed. At the end of the 60-day rearing period, the sex reversal rate was evaluated. The masculinization rate was higher in all treatment groups compared to the control group, with significant differences observed among the treatments. The highest masculinization performance was observed in groups T2 and T3, with rates of 96.67 ± 3.33% and 96.90 ± 2.76%, respectively. The lowest masculinization rate was recorded in the control group (44.53 ± 4.71%). Regarding survival, the highest rates were observed in groups T1 and T2 (100% and 98.89 ± 1.92%, respectively), while the lowest survival rate was recorded in group T3 (68.89 ± 5.09%). In conclusion, the optimal performance in both masculinization rate and survival was achieved in group T2 (300 mg/kg of feed). https://jfst.modares.ac.ir/article_28827.html Natural pigment-based pH indicators are promising candidates for intelligent food packaging due to their biocompatibility and distinct color responses. However, their practical application is limited by color stability and functional performance during storage. In this study, pH indicators incorporating betacyanin (Bet-Ind), anthocyanin (Ant-Ind), and phycocyanin (Phy-Ind) were prepared on cellulose filter paper, and their antibacterial activity, moisture absorption, and color stability were evaluated over 12 days under ambient (20 °C), refrigerated (4 °C), and frozen (−18 °C) conditions. Antibacterial assays revealed that all indicators inhibited the growth of Escherichia coli, Bacillus cereus, Listeria monocytogenes, and Staphylococcus aureus. The largest inhibition zone was observed against S. aureus (7 mm), while Phy-Ind exhibited the strongest effect on B. cereus (6 mm) and Ant-Ind showed the highest inhibition against L. monocytogenes (5.67 mm) (p < 0.05). Moisture absorption of the control filter paper increased from 0.35% to 10.56%, whereas pigment-based indicators demonstrated lower absorption, ranging from 9.12% to 10.09% (p < 0.05). Color stability analysis indicated that total color change (ΔE) was strongly dependent on pigment type and storage temperature. Betacyanin exhibited the highest stability under refrigeration (ΔE ≈ 7), phycocyanin showed minimal color change under freezing (ΔE ≈ 2.24), while anthocyanin displayed the greatest instability (p < 0.05). Overall, the findings highlight that pigment selection and storage conditions are critical factors in enhancing the performance of natural pH indicators for smart food packaging applications. https://jfst.modares.ac.ir/article_28779.html This study aimed to investigate the seasonal diversity of macrobenthic communities in the substrate of the Shalmanrud River estuary and to identify ecologically important species in the area. Following preliminary field surveys, four stations along a 600-meter stretch from the estuary to the upstream section were selected, and monthly sampling was conducted over a period of one year using a Ekman grab sampler having a sampling area of 0.3 m² and done in three replicates. Collected samples were fixed in 4% formaldehyde fixative and transferred to the laboratory of the Faculty of Basic Sciences, University of Guilan, for further research. Over one-year of sampling, a total of 745 macro benthic specimens were isolated and identified. The greatest taxonomic diversity was observed among bivalves, particularly in the families Mytilidae and Cardiidae. Among the identified macro benthos, the alien species Amphibalanus improvisus was also recorded. The detection of this species in a brackish and riverine environment indicated its high adaptability and habitat expansion potential, which could pose a warning for the structure of benthic communities. Some physico-chemical parameters, including water temperature, ambient temperature, pH, depth, and transparency, were also measured. Canonical Correspondence Analysis (CCA) revealed that water temperature and transparency were the most influential factors affecting the spatial distribution of dominant families, especially Mytilidae and Cardiidae, across different stations. Biodiversity was evaluated using Shannon, Simpson, and Pielou’s indices with the aid of PAST software. The study demonstrates that macro benthic diversity indices are a suitable tool for ecological monitoring, assessing the biological health of estuary-influenced rivers, and detecting biological threats such as the presence of alien species. https://jfst.modares.ac.ir/article_28826.html Aquatic animal diseases have emerged as a critical challenge in the fisheries and aquaculture sectors, posing significant threats to production efficiency and sustainability. In response, novel biotechnological approaches have been proposed to mitigate these issues. Among them, egg yolk-derived immunoglobulin (IgY), a naturally occurring antibody in birds, is gaining recognition as a promising tool for the diagnosis, prevention, and treatment of infectious diseases across a range of species, including livestock, poultry, aquatics, and even humans. Unlike mammalian IgG, IgY can be extracted non-invasively from egg yolk and does not cross-react with the mammalian complement system, thus minimizing potential immunological complications. These attributes render IgY a viable candidate for oral administration in animals and offer broad applicability in medical, pharmaceutical, and food industries. This review provides a comprehensive overview of IgY, encompassing its production, extraction, purification, microencapsulation, and practical applications in animal husbandry and aquaculture. Furthermore, the article examines the benefits and current limitations associated with the commercialization of IgY-based technologies. Despite recent advancements in its development and deployment, further progress in formulation optimization, stabilization techniques, and applied research is essential to fully realize the potential of IgY as an effective immunological tool in modern aquaculture practices. https://jfst.modares.ac.ir/article_28825.html The development of fish product exports is of particular importance for the expansion of non-oil exports due to their higher value added, longer shelf life, and greater ability to penetrate international markets. This study aimed to evaluate the comparative advantage and examine the export specialization pattern of Iran’s fish products over the period 2002–2023. To assess export competitiveness, the Revealed Comparative Advantage (RCA) index and its symmetric form were employed. In addition, a convergence model based on the Revealed Symmetric Comparative Advantage (RSCA) index was used to investigate the dynamics of export specialization, while a sanctions intensity variable was incorporated into the model. The results showed that the RCA index was greater than one throughout the study period, indicating that Iran enjoyed a comparative advantage in exporting this product group. Moreover, the RSCA index remained positive and relatively high in most years, with an average of about 0.88, suggesting a relatively stable competitive position for these products in the global market. The results of the specialization model also revealed that the lagged RSCA coefficient was positive and statistically significant at the 5% level, whereas the coefficient of sanctions intensity was not statistically significant. Overall, Iran’s fish product exports exhibited a relatively stable comparative advantage, and sanctions were not able to structurally alter the export specialization pattern of these products. https://jfst.modares.ac.ir/article_28966.html In this study, the diffusion of phosphate from fish farm cages located in the Royan marine area in the southern part of the Caspian Sea was studied using a 3D hydrodynamic numerical model including diffusion module for dissolved chemical pollutants in seawater. To perform numerical simulations, a bathymetry map with a geographical resolution of 15 arc-seconds, a wind time series with 6-hour intervals, and a monthly average temperature, salinity, and density field were applied to the model. To investigate the diffusion of phosphate released from the Royan fish farm cages, wind-induced currents were simulated in the entire Caspian Sea basin with a spatial resolution of 0.1° and then in the fine-scale model, from the Noor to Noshahr marine area with a geographical resolution of 0.0045°, the phosphate release pattern from the aforementioned cages was investigated in five consecutive fish farming periods from 2016 to 2020. The phosphate pollutant source was applied to the model at the location of the cages in the form of a continuous leak for 8 months and then a 4-month stop until the start of the next period.