Fish are a significant dietary source of various minerals essential for human health. This study examined the mineral profile (sodium, potassium, calcium, magnesium, iron, zinc, copper, iodine, selenium, and chromium) and harmful trace elements (mercury, lead, cadmium, and arsenic) in different parts of the bigeye ilisha (Ilisha megaloptera), including the backbone, head, abdominal fin and viscera, caudal fin, and fillet, from the northern coast of the Oman Sea. Results revealed significant variations in element concentrations among different parts, with higher mineral levels often found in waste parts compared to the fillet. Most minerals were present in amounts exceeding human dietary requirements, suggesting that processing waste parts of bigeye ilisha could be beneficial as food or dietary supplements. Additionally, the levels of harmful elements—mercury, lead, cadmium, and arsenic—were below permissible limits for human consumption. These findings support the potential for developing value-added products from bigeye ilisha.
The present study was carried out in the fishing grounds of small pelagic fish on Qeshm Island (namely Ramcha, Souza, Messen, and Salakh) from September 2022 to June 2023. Field sampling was performed by double-boat purse seiners and conducting 57 netting. The length, height, and mesh size of purse seines were 300 m, 50 m, and 10 mm (STR). Data of date, time of setting, location, and weight of target species and bycatch were recorded for each setting net. The mean CPUE (±95% CI) of small pelagic fish was overally obtained at 991.23 ± 157.14 kg per set. This was 1300 ± 364.01 for Salakh, 1246.88 ± 295 for Ramchah, 669.23 ± 214.20 for Messen, and 587.5 ± 155.71 for Souza, which there was a significant difference between Salakh and Ramcha compared to Souza and Messen (P<0.01). Also, the mean CPUE (±95% CI) of target catch for warm and temperate seasons were 1227.42 ± 224.11 and 709.62 ± 174.20 kg per setting net, which was significantly differ (P<0.01). The maximum and minimum of occurrence percentages were attributed to anchovy (with 100%) and Trichiurus lepturus (with 1.75%). The highest and lowest of mean CPUE (±95% CI) for bycatch species/groups, were related to the Trichiurus lepturus (1.75 ± 3.51) and Dasyatidae (0.07 ± 0.10) kg per setting. Given that fishing efforts have increased in recent years in the region, the estimated values of CPUE for target catch were smaller than in previous studies. Therefore, the fisheries managers must take immediate action to optimize the ongoing fishing effort.
The life cycle of barnacles usually consists of two stages: the free-swimming larval stage and the stationary stage. Their larval stage has 6 stages. Considering that plant essential oils showed anti-algae properties in previous studies, in this study, the toxicity of this essential oil was investigated on different stages of barnacle larvae of A. amphitrite species. Because they should not have a negative effect on the food chain. Also, in order to evaluate the toxicity effects of Z. multiflora essential oil on barnacle larvae as a study model. This test was performed based on the determination of LC50 in a 24-hour period on different stages of barnacle larvae, in such a way that in 24-well plates of each stock, 6 concentrations of 50, 25, 12.5, 6.25, 3.125, 1.5 µg/ml was prepared, then 1 ml of sea water and 10 barnacle larvae were added to each well and the number of dead and alive was checked by loupe. The obtained results showed that the LC50-14.198 µg/ml in the (VI ( stage of and the LC50-36.91 µg/ml in the) II( stage have a significant difference. Also, this plant essential oil showed a toxic effect on barnacle larvae at concentrations higher than 20 g/ml. But in general, the use of this herbal essential oil has significant biological activity due to having carvacrol as the main component of the essential oil. Also, by having different compounds such as phenolic, terpenoids and alkaloids, it can be a pioneer in the development of practical and bio-compatible with eco-management goals in low concentrations.
Given the increasing demand for proteinaceous food products, aquaculture production of fish is on the rise. Due to its attractiveness, marine cage culture has gained attention in the aquaculture industry and has become profitable. This study focuses on the hydrodynamic variables to determine suitable areas for establishing fish cage sites in the waters surrounding Qeshm Island. Hydrodynamic variables were estimated through one-year numerical modeling using Mike 21. By applying the Analytic Hierarchy Process (AHP) and fuzzy logic to the variables, suitable areas in four sections were identified: east of Qeshm Channel, south of Hormuz Island - between Qeshm City and Larak Island - north of Larak, the coast from Ramchah to Hengam Island, and Dayerstan bay to Salakh. The results indicate that, in addition to the previously identified areas in similar studies, the northern part of Larak Island and the center of eastern Qeshm Channel are also suitable and could be options for expanding this industry in the future with the development of cage technology and infrastructure. Areas identified in previous studies, such as the coasts from Souza to Shibderaz and Dayerstan Bay, may face significant wave height threats in severe storm conditions. However, areas like Dargahan can be less risky regarding hydrodynamic conditions due to limited fetch exposure in weather conditions. It is beneficial to conduct studies on cage deployment for development and planning of the maritime economy. By incorporating water quality indicators alongside hydrodynamic variables, more accurate results can be obtained, thereby reducing investment risks in this industry.
Lakes play a vital role in water conservation, biodiversity, tourism and job creation. However, seasonal changes, inflow of sewage and erosion increase the amount of nutrients discharged into the lakes and affect the structure of the ecosystem and the diversity of its planktons through the reduction of water quality. The purpose of this study was to identify the species composition and abundance of phytoplankton and zooplankton communities in Karon-4 lake to investigate the trophic indicators and water quality of this lake. For this purpose, after identifying 4 stations, sampling was done in 4 stages during 2017. Based on the results, 30 species of phytoplankton (belonging to 7 groups) and 58 species of zooplankton (belonging to 7 groups) were identified. The highest density of phytoplankton was observed in late summer and autumn, indicated the high values of soluble oxygen of the lake in these seasons beacause of increased photosynthetic activities. Most of the observed zooplankton species were also in the spring season and related to Copepoda, Rotifer and Cladocer. The average Shannon-Wiener and Margalf indices for phyto and zooplanktons indicated the improvement of living conditions and the possibility of the presence of more diverse species of zooplanktons due to the development of phytoplanktons in this lake. Therefore, in order to prevent algal bloom, in addition to controlling external factors (entry of various pollutants), attention should also be paid to internal conditions governing this dam. Finally, based on the abundance and diversity of species observed, this lake was classified as oligo-mesotrophic
The objective of this study was to assess the impact of a native probiotic product on the intestinal bacteria biodiversity of Penaeus vannamei. Shrimp larvae were administered the probiotic via food (treatment 1), through culture water (treatment 2), and a control group received no probiotics (treatment 3). After three months of rearing, bacteria were isolated from the shrimp intestines, and initial identification was conducted based on morphological, biochemical, and physiological traits. The diversity of intestinal bacterial flora was assessed using PCR-RFLP methods, focusing on the determination of 16S rRNA gene sequences. Results revealed a significantly higher abundance of cultivable bacteria in the intestines of shrimp from treatment 1 (2.4 x 107 CFU/gr) compared to those receiving probiotics through water (6.16 x 106 CFU/gr). The probiotic product led to a reduction in bacterial diversity in the intestines of treated shrimp, decreasing from 10 to 6 genera. Additionally, the frequency of Vibrio bacteria decreased by 20%, while other opportunistic pathogenic bacteria such as Pseudomonas, Aeromonas, Shewanella, and Photobacterium were eliminated. Overall, the findings suggest that administering probiotics through food was more effective in modulating the diversity of the shrimp intestinal microbiome. This study enhances our understanding of the impact of indigenous probiotics on the composition and dynamics of the intestinal microbiome of P. vannamei.
The aim of this study was to examine the accumulation of lead, nickel, and cadmium heavy metals in the muscle tissue of Peronia peronii in the waters of Bandar Lange and Qeshm in April. Thirty samples were separately collected from each station and subjected to drying and acid digestion before measurement using a flame atomic absorption device (GBC model F savant). The results revealed varying levels of metal accumulation, with the highest and lowest concentrations recorded as 0.112 and 0.024 micrograms per gram for nickel and cadmium, respectively, in Langeh and Qeshm ports. Additionally, a significant relationship between the concentration of nickel, lead, and cadmium and the average total weight of P. peronii was observed, indicating a positive correlation with the total weight (p<0.05). However, no significant relationship was found between the accumulation of these metals and the average total length of P. peronii in Bandar Lange and Qeshm Island, indicating a lack of correlation with the total length of the flounder seaweed (p>0.05).
The phenomenon of climate change due to the expansion of human industrial activities is rapidly advancing, and via disrupting ecological processes and destroying the habitats, has caused extinction of many fishes and reducing the biodiversity of aquatic ecosystems. This study predicts the distribution of Ponticola gorlap under two climate scenarios (RCP 2.6 and RCP 8.5) for the years 2050 and 2080 using the MaxEnt model. Five climatic and environmental variables, including annual mean temperature, annual precipitation, annual temperature range, flow accumulation, and slope, were utilized for forecasting. The model demonstrated excellent performance (AUC criterion: 0.969) in predicting species distribution. Annual temperature range identified as the most influential variable (importance score: 57/5) in determining the species' distribution. Moreover, the study forecasts a significant decrease in the distribution of P. gorlap under both optimistic and pessimistic scenarios for the years 2050 and 2080. As climate change intensifies and suitable habitat ranges diminish, the species faces an elevated risk of extinction in the future. Hence, experts and policy-makers should focus more on conservation measures.
Zebrafish (Danio rerio) stands as a valuable model organism for delving into molecular mechanisms, notably detoxification. MicroRNAs (miRNAs), small non-coding RNA molecules, serve as post-transcriptional regulators of gene expression, potentially shaping the complex network of genes engaged in detoxification pathways. This study employs bioinformatic analysis, utilizing Target Scan and DIANA databases, to explore the potential of miRNAs in modulating the expression of detoxification-associated genes in zebrafish. By meticulously scrutinizing miRNA and mRNA datasets in zebrafish, we pinpoint candidate miRNAs predicted to target established detoxification genes. Leveraging bioinformatic algorithms, we dissect the plausible interactions between these miRNAs and their target detoxification genes, which include pgp, gpx1a, gpx3, aldh3b1, gstm3, cyp3c1, gstp1, gpx1b, cyp17a1, sod1, sod2, gsto2, gstz1, akr7a3, gsr, ahr1b, cat, ahr2, and abcb4. Moreover, we assess the conservation of miRNA-target interactions across species and scrutinize potential miRNA binding sites within the 3' untranslated regions (UTRs) of target mRNAs. Our findings unveil the intricate regulatory interplay between miRNAs and genes involved in detoxification in zebrafish, providing a cornerstone for future experimental validations. This study significantly contributes to our evolving understanding of miRNA-mediated gene regulation within the context of detoxification pathways in zebrafish
limited information available regarding their biology. Considering the significance of bivalve gonads as vital reproductive organs, this study aimed to identify and investigate the histological structure of reproductive organs of dominant bivalve species throughout one year, from April 2021 to February 2022, in the Karkeh River. For this purpose, bivalves were seasonally collected, identified, and then dissected. Subsequently, the gonads underwent histomorphometric examination following tissue processing stages. The results indicated that Unio tigridis and Pseudodopsis euphratica were the predominant species in the Karkeh River, both belonging to the Unionidae family. The ovaries in both species exhibited asynchronous development. The reproductive cycle throughout the year comprised three stages: undeveloped, developing, and mature. Considering gonadal maturity in spring and spawning in summer, it appears that the primary gonadal activity of both species in the Karkeh River in the study area occurs in spring, while peak reproductive activity takes place in summer
The study conducted in June 2022 at Azini Lagoon aimed to assess trace element concentrations within sediment and Telescopium telescopium species. Thirty T. telescopium gastropod specimens were collected from sediment surfaces, alongside six sediment samples acquired using a plastic shovel. Analysis revealed a sequence of metals in sediment samples: Fe ˃ Ni ˃ V ˃ Pb ˃ Cd, while T. telescopium muscle tissue exhibited: Fe ˃ Pb ˃ Ni ˃ V ˃ Cd. Notably, average concentrations of nickel, lead, vanadium, and iron in surface sediments surpassed those found in T. telescopium (P≤0.05). Conversely, no significant difference was observed in cadmium concentration between sediment and T. telescopium (P≥0.05). Moreover, sediment bioaccumulation of elements was computed to be lower than one, indicating insignificant element bioaccumulation in sediment, except for cadmium, which exceeded this threshold. Enrichment values for the mentioned elements, excluding nickel, suggested no enrichment in the region's surface sediments. Additionally, calculated land accumulation values for all elements in Azini Lagoon sediments indicated a non-contaminated state, implying that these elements hadn't induced specific pollution in the area.
Aquatic and semi-aquatic plants are vital components of aquatic ecosystems, contributing significantly to their ecological balance. This study focused on the analysis of marginal plants along the Arvandroud, conducting seasonal samplings with 1 x 1 square meters and 3 repetitions at each station across two periods: summer 2015 and winter 2016. The collected samples underwent pressing for herbarium studies. The survey identified 25 plant species spanning 11 families. Among these, 5 were monocotyledonous, encompassing Poaceae and Cyperaceae, while 18 were dicotyledonous, including Lamiaceae, Capparaceae, Fabaceae, Asteraceae, Convolvulaceae, Apocynaceae, Amaranthaceae, Tamaricaceae, and Polygonaceae. Notably, the dominant marginal plants observed during summer were Phragmites australis (Cav.) Trin. Ex. Steudel and Cyperus longus L., while in winter, it was Phragmites australis, Cyperus longus, and Senecio glaucus L. Phragmites australis emerged as the dominant species based on its density across both seasons. Principal Component Analysis (PCA) revealed the influential environmental factors affecting these plants, with sediment particles, total organic matter, salinity, and electrical conductivity identified as the most significant. Interestingly, plant density was higher in winter compared to summer, highlighting seasonal variations in plant distribution along the Arvandroud.
The aims of the present study were to investigate the macrobenthos communities in the Caspian Sea and to investigate the pollution of this ecosystem based on the pollution indices ABC (Abundance Biomass Comparison), BC (Biotic Coefficient) and ABC curve in 2018 (autumn and winter) and 2019 (spring and summer). According to the results, polychaetes, crustaceans, and bivalvia formed the major groups of macrobenthos communities with 4, 11 and 1 species, respectively. The polychaetes (mainly Streblospio gynobranchiata) included about 70% of the total abundance and the group of bivalvia (Cerastoderma glucaum) included about 76-93% of the macrobenthos in all seasons except in spring. The mean values of the Shannon index and evenness indices were calculated as (1.56) and (0.55), respectively. The annual pollution (ABC) and BC indices were obtained as -3.1 and 2.7, respectively. These values along with characteristics of ABC curve indicate severe stress caused by pollution in the Caspian Sea ecosystem. In this study, the percentage abundance of the invasive species S. gynobranchiata in macrobenthos communities was 52%, which is about 10% decrease compared to 2009 and 2010. This decreasing trend can be considered as positive evidence in the improvement process of the ecosystem in this part of the food chain. However the continuity of recovery trend needs more time, no force by new stressors, proper management, and reduced pollutions into the ecosystem.
The widespread use of produced metal oxide nanoparticles has raised major concerns about their impact on human health and aquatic organisms. The aim of the present study was to determine the effects of iron oxide nanoparticles (FeO) and microalgae Spirulina platensis on the gills of gray mullet (Mugil cephalus) in four groups, i.e., first or control (without iron oxide nanoparticles and algae extract), second (15 mg/kg iron oxide nanoparticles), third (300 mg/kg algae extract) and fourth (15 mg/kg iron oxide nanoparticles and 300 mg/kg algae extract) during three periods of 3, 14 and 28 days. For this purpose, 72 specimens of gray mullet were acclimated to the experimental condition and exposed to different concentrations of iron oxide nanoparticles and algae extract in the mentioned groups and time periods. Then the gill tissue of each fish was sampled and the slide tissues were prepared. The gill tissue complications were hyperplasia, hyperemia, secondary lamella shortness, secondary lamella fusion, lamella deformity, epithelial detachment, and lamella clubbing. The fourth group showed more complications in all three time periods, and after that, the second and third groups showed more respectively. The more exposure time caused more tissue complications and the highest number of complications was observed on day 28. Also, algae had no effect on reducing tissue complications in fish, while it caused tissue complications but with less intensity. Based on the results, iron oxide nanoparticles can endanger fish health over time. Therefore, further studies are needed to evaluate its potential toxic effects.
