Search

The increasing production of plastic products has raised concerns about environmental impacts related to microplastic formation, which harms ecosystems and human health. This systematic review aims to present the concentration of microplastics in commercially important bony fish and discuss the impacts on animal health and the possibility of these contaminants reaching the end consumer. The PICO methodology was used, and 517 articles were retrieved from four databases (PubMed, Embase, Web of Science, and Scopus); after selecting articles that complement the research objective, 70 articles were used to compose this review. According to the results, line-shaped microplastics, polypropylene, and polystyrene polymers were the most frequently identified in the articles. Additionally, the effects of microplastics on animal health, including false satiety and physical injuries, as well as risks to human health, such as epithelial inflammation, oxidative stress, and cell contamination, were discussed. Understanding the concentration of microplastics in commercially important bony fish is necessary for protecting human health and maintaining the health of marine ecosystems. It is necessary to adopt legislative measures for proper plastic disposal. [ABSTRACT FROM AUTHOR]

The study aimed to assess microbiological parameters, antibiotic concentrations, and formaldehyde residues in four fish species - Wallago attu, Labeo rohita, Pangasianodon hypophthalmus, and Rastrelliger kanagurta - sourced from both inland and marine sectors, encompassing culture and capture fisheries. These fish were collected from the Amritsar, Jalandhar, Ludhiana, Mohali, and Bathinda fish markets in Punjab, India, over four distinct seasons (post-monsoon, winter, pre-monsoon, and monsoon) from September 2021 to August 2022. The study focused on evaluating Total Plate Count (TPC), Escherichia coli, and Staphylococcus aureus. Additionally, it investigated antibiotic residues and formaldehyde presence to ensure consumer safety. TPC levels in various fish species ranged from 1.193.22×104 cfu/g across different seasons and markets. Elevated levels of E. coli (2.46 - 4.46×10² cfu/g) and S. aureus (2.33 - 4.73×10³ cfu/g), exceeding permissible limits, presented a notable public health concern. The monsoon season recorded the highest microbiological counts in all fish species sampled. Bathinda's fish market had higher average microbiological values compared to the other markets, potentially due to factors like ice quality, hygiene standards during packaging, and storage and transportation processes. In terms of antibiotic residues, the concentrations of chloramphenicol (0.001 - 0.019 µg/kg), nitrofurantoin (0.001 - 0.026 µg/kg), and oxytetracycline (0.001 - 0.028 µg/kg) in the selected species were found to be below permissible limits, ensuring the fish's safety for consumption. No formaldehyde residues were detected in any of the fish species across all seasons and markets, further confirming their safety. Addressing bacterial contamination through scientific interventions remains essential for public health and environmental sustainability.

Microplastics are an emerging pollutant of marine environments, affecting fish and other marine biota such as copepods and rotifers. The current study assesses the impact of plastic microbeads on the growth of roho (Labeo rohita) in a 4-month feeding experiment under laboratory conditions. Over a period of 120 days, roho fingerlings were exposed to different concentrations of plastic microbeads (50 mg to 200 mg/kg of feed) mixed into their feed. It was found that the ingestion of plastic microbeads negatively affected the growth of roho and that the concentration of the plastic microbeads directly influenced the growth rate of the fish.

Genetic structure and connectivity information can be used to identify biological corridors and prioritize the conservation of areas that help maintain ecosystem integrity. Some marine fish, especially those of commercial interest, have been proposed as suitable indicators to identify potential marine biological corridors due to their high mobility among habitats and socioeconomic importance. In this study, we assessed the genetic structure of lane snapper populations in the Honduran Caribbean to evaluate connectivity and identify potential environmental barriers. Furthermore, we evaluated the genetic characteristics of the lane snapper on a larger spatial scale, including populations across the rest of its distribution range in the western Atlantic, using mtDNA and nuDNA markers. Our results demonstrate a significant genetic diversity of lane snappers in the Honduran Caribbean. Furthermore, despite their high dispersal potential, we observed genetic structuring in lane snapper populations on a larger spatial scale, resulting in the formation of two distinct groups throughout their distribution range: group 1 from Florida, the Gulf of Mexico, Honduras, and Colombia and group 2 from Puerto Rico and Brazil. This genetic differentiation can be attributed to oceanographic barriers such as river plumes and marine currents. These findings have the potential to significantly impact marine conservation and management efforts in the region, both at local and regional scales. It is anticipated that they will not only inform but also elicit a response, driving further action towards effective conservation measures. At a local scale, we recommend that conservation efforts focus on protecting critical habitats. At a regional scale, lane snappers should be included in the management plans of existing marine protected areas necessary to ensure the long-term sustainability of the species and the marine ecosystems in which it resides. [ABSTRACT FROM AUTHOR]

Microplastics are an emerging pollutant of marine environments, affecting fish and other marine biota such as copepods and rotifers. The current study assesses the impact of plastic microbeads on the growth of roho (Labeo rohita) in a 4-month feeding experiment under laboratory conditions. Over a period of 120 days, roho fingerlings were exposed to different concentrations of plastic microbeads (50 mg to 200 mg/kg of feed) mixed into their feed. It was found that the ingestion of plastic microbeads negatively affected the growth of roho and that the concentration of the plastic microbeads directly influenced the growth rate of the fish. [ABSTRACT FROM AUTHOR]

The presence of potentially harmful metals in commercially available saltwater fish has been extensively documented in scientific literature. This has demonstrated the significance of monitoring the crucial copper (Cu) levels in fish fillets from a perspective focused on human health risks (HHR). This study aimed to evaluate the human health risk (HHR) associated with the presence of Cu in 40 different species of commercial marine fish purchased from Malaysia. The fish samples were gathered from various sources from April to May 2023. The 40 species of commercial marine fish had concentrations of Cu (0.72–82.3 mg/kg dry weight) that fell below acceptable levels defined by seafood safety recommendations. Therefore, these fish are considered good sources of the essential element. The target hazard quotient values for Cu were below 1, suggesting that the hazards of Cu from fish eating are non-carcinogenic. Furthermore, it was discovered that the computed values for the predicted weekly consumption were lower than the defined provisional tolerated weekly intake of Cu. Consuming fish purchased from Malaysia is unlikely to harm consumers’ necessary copper intake. However, it is crucial to consistently monitor the safety of consumers who heavily depend on commercially caught marine fish from Malaysia. This monitoring is an essential aspect of implementing environmental, social, and governance (ESG) practices, which industries are concerned about and report on annually.

Microplastic ingestion by marine fishes has been of particular interest, as many species are the target of commercial fisheries and, thus, have a strong connection with human health. Consumption of microplastic thru seafood is likely to have harmful effects on people globally but mainly on social groups that highly depend on fisheries for self-consumption. Here, we first aim to characterize the presence of microplastics in species targeted by small-scale fishers; and explore if the fish consumption of microplastic particles is associated with biological factors. Second, we applied semi-structured interviews to small-scale fishers to investigate, from a socio-environmental perspective, the potential social and environmental impacts of contamination by microplastics on the local communities. We found that commercially important fish families regularly contained microplastics in their tissues, and the consumption of microplastics by fish caught through traditional fishing gear depends on traits such as species mobility but the microplastic load also depended on the type of fishing gear used. Species with a wide home range had a higher load of microplastics than fish with a small home range but also seemed to be related to the fishing method. The observed differences in microplastic content on target species are likely to be transferred to humans in a non-random fashion. This work implies that microplastic pollution in commercial fish might represent an environmental and social issue that is not well understood by the fishing community in the Mexican Caribbean, with potential ramifications for marine resource management. [ABSTRACT FROM AUTHOR]

The Bay of Bengal (BoB) is home to a range of commercially important species with different food habits and feeding features. Microplastic (MP) contamination in the fish of BoB, like in many other marine environments, is a significant environmental concern. The study aimed to investigate the presence of microplastics (MPs) in the gastrointestinal tracts (GITs) of selected commercial marine fishes from the Bangladesh coast of the BoB. Six fish species (Escualosa thoracata, Tenualosa ilisha, Johnius belangerii, Trichiurus lepturus, Planiliza parsia, and Mystus gulio) were investigated (n = 120) following hydrogen peroxide digestion, and floatation (saline solution) protocols. After analyses, a total number of 696 MPs (dimension 0.3 to 5 mm) were identified. Moreover, the highest occurrence of MPs in fish GITs was found in planktivorous fish (average of 7.7 items/individual), followed by omnivorous (average of 5.2 items/individual), and carnivorous fish (average of 4.6 items/individual) (p < 0.001). However, planktivorous E. thoracata showed the highest number of MPs per g of GIT (average of 30.99 items/g GIT), whereas T. ilisha showed the lowest count (average of 0.77 items/g GIT). Different types of MPs (fibers (19 to 76%), fragments (6 to 61%), films (8 to 35%), microbeads (0 to 5%), and foams (0 to 2%)) were also observed. In terms of the color of MPs, the transparent, black, green, and blue types were the most common. Polymers were found as polyethylene (35 to 43%), polyethylene terephthalate (28 to 35%), polyamide (20 to 31%), and polystyrene (0 to 7%). The study provides a significant incidence of MPs in fish from the Bangladesh part of the BoB, which is very concerning. Therefore, long-term research is indispensable to ascertain the variables affecting the presence of MPs in fish, their origins, and their potential effects on the BoB fisheries. Stringent policies on plastic use and disposal should be strongly urged in this coastal region. [ABSTRACT FROM AUTHOR]

The presence of potentially harmful metals in commercially available saltwater fish has been extensively documented in scientific literature. This has demonstrated the significance of monitoring the crucial copper (Cu) levels in fish fillets from a perspective focused on human health risks (HHR). This study aimed to evaluate the human health risk (HHR) associated with the presence of Cu in 40 different species of commercial marine fish purchased from Malaysia. The fish samples were gathered from various sources from April to May 2023. The 40 species of commercial marine fish had concentrations of Cu (0.72–82.3 mg/kg dry weight) that fell below acceptable levels defined by seafood safety recommendations. Therefore, these fish are considered good sources of the essential element. The target hazard quotient values for Cu were below 1, suggesting that the hazards of Cu from fish eating are non-carcinogenic. Furthermore, it was discovered that the computed values for the predicted weekly consumption were lower than the defined provisional tolerated weekly intake of Cu. Consuming fish purchased from Malaysia is unlikely to harm consumers' necessary copper intake. However, it is crucial to consistently monitor the safety of consumers who heavily depend on commercially caught marine fish from Malaysia. This monitoring is an essential aspect of implementing environmental, social, and governance (ESG) practices, which industries are concerned about and report on annually. [ABSTRACT FROM AUTHOR]

This study analysed the catches of trap fishing in the Canary Archipelago, NE Atlantic Ocean. This study was conducted from October 2016 to September 2017, April to November 2018 and September 2020, in five ports (San Cristóbal, Taliarte, Castillo del Romeral, Arguineguín and Mogán).The primary gear were traps with small mesh size (31.6 mm) and large mesh size (50.8 mm). A total of 2587 small mesh size traps and 141 large mesh size traps were analysed from 20‐ to 130‐m depth.The main target species were Dentex gibbosus and Stephanolepis hispidus.Catches of traps with large mesh size showed D. gibbosus above first maturity and S. hispidus in small mesh size traps. Both species exhibit larger specimens during reproductive periods.The most effective traps for D. gibbosus (large mesh) were located on the western coast (>30‐m depth), with the highest catch per unit of effort (CPUE) in Mogán (857.7 g trap−1 day−1). The most effective traps for S. hispidus (small mesh) were located in southern areas, especially in sandy habitats (124.9 g trap−1 day−1 in Castillo del Romeral, 102.9 g trap−1 day−1 in Arguineguín).The highest catchability of D. gibbosus was observed in April (CPUE of 962.8 g trap−1 day−1), and the highest catchability of S. hispidus was found in June (CPUE of 165.9 g trap−1 day−1).The traps with small mesh size showed a great selectivity of sizes for S. hispidus; though high catch rates of immature specimens of D. gibbosus pose a threat to species conservation.The management recommendations' proposed measures include revising minimum catch sizes for both species. Additionally, we suggested depth limitations for mesh sizes of traps.The study highlights the need for new management strategies to ensure the conservation of targeted demersal species, with special emphasis on addressing the threat posed by small mesh sizes to immature D. gibbosus.The findings provide valuable insights for adapting fishery management practices to sustainably conserve the targeted species in the Canary Archipelago. [ABSTRACT FROM AUTHOR]

Despite the wide distribution of textile microfibers in the marine environment, there is still limited knowledge on microfiber ingestion in fish species intended for human consumption, mostly due to analytical issues. The present study aims to assess the occurrence of microfibers in red mullet (Mullus barbatus) samples collected from the Italian waters of the central Adriatic Sea. M. barbatus is a bottom fish that lives in contact with sediment and therefore was proposed as a sentinel species for the monitoring plastic pollution. A visual approach based on the evaluation of specific microfiber surface morphology was applied for the identification of particles of different origins. The preliminary findings showed the presence of microfibers in 80% of red mullet samples with a mean of 5.95 microfibers/individual. The majority (>80%) of the isolated microfibers were of natural/artificial origin, while the dominant colors were blue and black. The obtained results confirmed that benthic fish species are susceptible to microfiber ingestion and indicate the high availability of these particles in the Adriatic basin. Considering the spectroscopic drawbacks in microfiber analyses and the need to improve the current knowledge on the rate of contamination of fishery products, the visual approach could be a feasible, easy, and accessible method in the study of microfiber pollution, and the assessment of consumer health risks.

The increasing production of plastic products has raised concerns about environmental impacts related to microplastic formation, which harms ecosystems and human health. This systematic review aims to present the concentration of microplastics in commercially important bony fish and discuss the impacts on animal health and the possibility of these contaminants reaching the end consumer. The PICO methodology was used, and 517 articles were retrieved from four databases (PubMed, Embase, Web of Science, and Scopus); after selecting articles that complement the research objective, 70 articles were used to compose this review. According to the results, line-shaped microplastics, polypropylene, and polystyrene polymers were the most frequently identified in the articles. Additionally, the effects of microplastics on animal health, including false satiety and physical injuries, as well as risks to human health, such as epithelial inflammation, oxidative stress, and cell contamination, were discussed. Understanding the concentration of microplastics in commercially important bony fish is necessary for protecting human health and maintaining the health of marine ecosystems. It is necessary to adopt legislative measures for proper plastic disposal.

Despite the wide distribution of textile microfibers in the marine environment, there is still limited knowledge on microfiber ingestion in fish species intended for human consumption, mostly due to analytical issues. The present study aims to assess the occurrence of microfibers in red mullet (Mullus barbatus) samples collected from the Italian waters of the central Adriatic Sea. M. barbatus is a bottom fish that lives in contact with sediment and therefore was proposed as a sentinel species for the monitoring plastic pollution. A visual approach based on the evaluation of specific microfiber surface morphology was applied for the identification of particles of different origins. The preliminary findings showed the presence of microfibers in 80% of red mullet samples with a mean of 5.95 microfibers/individual. The majority (>80%) of the isolated microfibers were of natural/artificial origin, while the dominant colors were blue and black. The obtained results confirmed that benthic fish species are susceptible to microfiber ingestion and indicate the high availability of these particles in the Adriatic basin. Considering the spectroscopic drawbacks in microfiber analyses and the need to improve the current knowledge on the rate of contamination of fishery products, the visual approach could be a feasible, easy, and accessible method in the study of microfiber pollution, and the assessment of consumer health risks. [ABSTRACT FROM AUTHOR]

The increased demand and consumption of synthetic textiles have contributed to microplastic pollution in the form of microfibers. These particles are widely spread in the aquatic environment, leading to the exposure of marine biota, including edible species. The current study aimed to assess the extent of microfiber contamination in a commercially relevant fish species, Merluccius merluccius, which is considered a small-scale bioindicator for the monitoring of plastic ingestion in the Mediterranean coastal environment. The frequency of ingestion, abundance, and composition of textile microfibers isolated from the fish gut were characterized. Results showed the occurrence of microfibers in 75% of the samples, with a mean number of 10.6 microfibers/individual, of which 70% were classified as natural microfibers. The spectroscopic analyses confirmed both the visual identification of microfibers and the prevalence of cellulosic fibers. The obtained findings provided evidence of both natural/artificial and synthetic microfiber exposure in an important commercial fish species that, considering the consumption of small individuals without being eviscerated, may be a potential route of microfiber exposure in humans. Monitoring programs for fishery products from markets are needed to assess contamination levels and human health risks. In addition, measures to control microfiber pollution need to occur at multiple levels, from textile industries to international governments.

Genetic structure and connectivity information can be used to identify biological corridors and prioritize the conservation of areas that help maintain ecosystem integrity. Some marine fish, especially those of commercial interest, have been proposed as suitable indicators to identify potential marine biological corridors due to their high mobility among habitats and socioeconomic importance. In this study, we assessed the genetic structure of lane snapper populations in the Honduran Caribbean to evaluate connectivity and identify potential environmental barriers. Furthermore, we evaluated the genetic characteristics of the lane snapper on a larger spatial scale, including populations across the rest of its distribution range in the western Atlantic, using mtDNA and nuDNA markers. Our results demonstrate a significant genetic diversity of lane snappers in the Honduran Caribbean. Furthermore, despite their high dispersal potential, we observed genetic structuring in lane snapper populations on a larger spatial scale, resulting in the formation of two distinct groups throughout their distribution range: group 1 from Florida, the Gulf of Mexico, Honduras, and Colombia and group 2 from Puerto Rico and Brazil. This genetic differentiation can be attributed to oceanographic barriers such as river plumes and marine currents. These findings have the potential to significantly impact marine conservation and management efforts in the region, both at local and regional scales. It is anticipated that they will not only inform but also elicit a response, driving further action towards effective conservation measures. At a local scale, we recommend that conservation efforts focus on protecting critical habitats. At a regional scale, lane snappers should be included in the management plans of existing marine protected areas necessary to ensure the long-term sustainability of the species and the marine ecosystems in which it resides.

The globalized production chains of fish products have been posing increasing difficulties in carrying out proper food control on any level. In case of species identification, morphological examinations that are usually efficient to identify entire fishes, fresh or frozen, fail when applied to fish derivative products, such as fillets or canned meat. In this study we evaluated the global distribution of tilapia COI haplotypes and haplogroups, contrasting diversity in native range and areas where Oreochromis spp. are regarded as introduced. Introduced areas showed a lower diversity of haplotypes comparatively to native areas, evidencing that cultures in different parts of the world originated from a few strains in Africa. Afterwards, evaluating COI diversity from tilapia fillets of the Brazilian market, we concluded that diversity in Brazilian cultures is similar to other countries where they were introduced, but it was highly heterogeneous among brands. Since part of the global movement on tilapia culture relies on crossbreeding of tilapia lineages, the difficulty in defining specific strains of tilapia through DNA barcodes is thought to increase. Our haplotyping system presents a practical form of molecular identification for tilapia products that may be useful in future taxonomic reviews. However, the estimated genetic diversity of Oreochromis through the COI marker does not necessarily reflect the diversity of species in the group, but rather the evolutionary history of this marker. Nevertheless, given the costs and feasibility of analyzing multiple markers, such as microsatellites, the current haplotyping standard is an improvement over the previous system.

Parasitic organisms, being an integral part of natural and technogenically transformed ecosystems, can serve as indicator species that reflect the impact on the environment, reacting to changes in the habitat with changes in physiology or chemical composition. Ectoparasites, due to the fact that they can interact with the environment in various ways, they are able to provide information about the hydro- and geochemical background of the environment due to their presence or absence. Endoparasites, in turn, are less susceptible to toxic substances, demonstrating the ability to accumulate environmental toxicants inside their tissues. The state of the environment has a significant impact on parasites, determining their quantitative and qualitative indicators of the population structure. In this regard, there is a need for systematic monitoring of ichthyoparasitological studies in the reservoirs of Northern Kazakhstan, using fish parasites as indicator species. The article presents the data of ichthyoparasitological studies conducted in the reservoirs of Northern Kazakhstan (Akmola, Pavlodar and North Kazakhstan regions), as a result of which 23 species of parasitic organisms were identified, including 1 species of zoonotic (Raphidascaris acus) and 2 species of highly virulent (Gyrodactylus cyprini, Schyzocotyle acheilognathi) helminths. Gyrodactylus cyprini, Gyrodactylus cernuae, Eudiplozoon sp., Diplostomum paraspathaceum, Diplostomum chomatophorum were first established for reservoirs of northern Kazakhstan. In the backwater of the Chernoyarsk basin, the Irtysh can be considered unfavorable for ergasileous parasitosis. [ABSTRACT FROM AUTHOR]

Copyright of German International Journal of Modern Science / Deutsche Internationale Zeitschrift für Zeitgenössische Wissenschaft is the property of Artmedia24 and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Microplastics are omnipresent in the marine environment. Their bioaccumulation in fish and other marine biota is a concern due to the potential human health risks from exposure through seafood sold in markets. There is a global effort afoot to take inventory of microplastic contamination in the world’s main water bodies. This includes an understanding of the sources, the trophic transfer and the fate of microplastics in aquatic systems. Studies on the state of microplastic pollution in the Red Sea have appeared only in the last 5 years. Nevertheless, they gave insight into the abundance of microplastic particles within the marine environment of the Red Sea. The following is a review of these studies.

Dietary uptake is well known as the predominant pathway of heavy metal bioaccumulation in organisms. Our study used a typical tropical reservoir and fish as a modeling system to test the hypothesis that feeding habits and living habitats significantly affect heavy metal bioaccumulation in fish. Specifically, Cr, Mn, Fe, Ni, Cu, Zn, Cd, and Pb concentrations in water, sediment, and fish, and δ13C and δ15N in 13 fish species were detected in the Songtao Reservoir of Hainan Province, southern China. Our results indicated that Zn concentration in carnivorous fish was higher than in omnivorous fish. Principal components analysis visually differentiated pelagic, benthopelagic, and demersal fish groups. Moreover, we found that the fish feeding in the demersal habitat showed higher heavy metal levels than those in the pelagic habitat. Additionally, the heavy metal contents in demersal fish were significantly positively correlated with sediments, while no positive correlation was observed in pelagic-feeding fish. The δ15N and the concentration of Ni, Zn in fish had a significantly positive correlation, suggesting the potential biomagnification. In contrast, Ni, Fe, Cu, and Cd negatively correlated with fish body weight/length, indicating the growth dilution effects. Finally, the estimated daily intake (EDI) of the metals was far below the provisional tolerable daily intake (PTDI), and target hazard quotients (THQ) were <1.0, indicating that the fish had no risk for consumption risks. Overall, our finding partially validated the hypothesis that the feeding habits and living habitats significantly influence heavy metal bioaccumulation in fish, which might be a broad generality for metal exposure scenarios in aquatic environments. [ABSTRACT FROM AUTHOR]

This study was conducted to investigate the shape and morphological characteristics of otolith in some of economic fishes in Anzali wetland and the possibility of using these characteristics to identify species. In this study, Sajita otolith was extracted from 5 species of fishes and their morphological characteristics were investigated. These species belong to the families of Esocidae (Esox lucius), Leuciscidae (Abramis brama), Xenocyprinidae (Hypophthalmichthys mollitrix), Mugilidae (Chelon saliens) and Percidae (Sander lucioperca). The species were selected and their biometric characteristics and their otoliths were recorded and extracted. Then, the shape of the otoliths was studied and the biometric characteristics of the left and right otoliths of each sample were recorded by measuring their length, width and thickness. Also, the size, elongation and thickness indices of otolith were calculated and the relationship between the parameters was investigated. The results showed that the shape of otolith among these species and even species belonging to one family were different. The highest weight, head lengths and otolith lengths were not observed in the largest sample. There was a significant positive relationship between total lengths and otolith lengths in Chelon saliens and Sander lucioperca. Also, a positive and significant relationship was observed between the weight and thickness of otolith in Chelon saliens. So, the morphology of otoliths can play an important role in the taxonomy of fish. [ABSTRACT FROM AUTHOR]

Today microplastics (MPs) have received worldwide attention as an emerging environmental pollution which is one of the four major global environmental threat and health hazard to human as well. Unfortunately, MPs have been founded in the all environments and media include air, water resources, sediments, and soil. It should not be forgotten MPs have also been detected in food and processing products like tuna. MPs can be ingested by marine organisms such as zooplankton, fish and birds. Accumulation and distribution of MPs by commercially important aquatic organisms is expected to lead to greater exposure risk for human populations with possible adverse effects over time. The aim of this work was to review the published literature regarding the contamination of commercial fish muscle for human consumption. Furthermore, a short revision of the environmental contamination and human health effects by MPs are included. We also estimated human daily intake considering the worldwide contamination of commercial fish muscle ranged from 0.016 items/g muscle of fish to 6.06 items/g muscle of fish. MPs have been found in 56.5% of the commercial fish samples analysed here. As fish is used in human food table across the word, they constitute a long-term exposure route for all humans and raise the concern about the potential public health risk. [ABSTRACT FROM AUTHOR]

Since the 1930s, a number of fish taxa have been recorded from the marine waters of Magallanes in Sorsogon, Philippines. However, it has only in 1995 that the checklist was properly updated, in which the number of recorded species plummeted but has yet to reach a plateau. While the actual field surveys on natural habitats are a common approach to obtaining fish records, market surveys are also proven equally aidful. Here, we present an updated checklist of all named species of fish vended in Magallanes markets - including their local name, origin, and temporal availability. Sourced from Sorsogon Bay and Ticao-Burias Pass, a total of 77 species were identified. Thirteen species set new records for Sorsogon Bay. The Ticao-Burias Pass was the exclusive source of 11 taxa. A total of 61 species were sourced from either site. The current list of marketed fish from Magallanes represents 20% with that of the entire fish records reported from Sorsogon Bay. The fish species composition varied both in terms of origin and seasonal availability. Comparison of the present list of commercial fish in Magallanes against other records elsewhere in the Philippines may not be possible at the present, as previous studies indicated different sampling efforts, wider area coverage, and longer cumulative observation period. Return efforts and further market survey studies are expected to augment the current number of recorded fish taxa. Our present study makes recommendations for the continued use of market surveys to help update and verify records of fish diversity in a given area. [ABSTRACT FROM AUTHOR]

Helminths affect multicellular animals of all types except echinoderms and sponges. In particular, within Volga reservoirs, the infestation of commercial fish by Pseudophyllidea larvae, Opisthorchis felineus (Rivolta, 1884) metacercaria, and other parasitic worms has increased significantly. This poses a threat of growing infestations in humans. The Vazuz Reservoir is a part of the large Vazuz hydrotechnical system connected with the Moscow River and is actively used for water supply to the Western and Southwestern districts of the capital. The investigated impounding reservoir is located on the border of the Tver, Moscow and Smolensk Regions. Most of the population in these regions actively promotes fishing as a hobby. Helminth fauna monitoring is relevant due to the active catch fish consumption by the population. The purpose of this study was to assess epizootic helminthiasis within the Zubtsovsky District of the Tver Region due to the special activity of using the Vazuz Reservoir by professional and amateur fishers. The objects of the study were three commercial fish species widely represented in this water area: river perch Perca fluviatilis Linnaeus, 1758, common roach Rutilus rutilus (Linnaeus, 1758), and common bream Abramis brama Linnaeus, 1758. The fish were caught at two points of the Vazuz Reservoir right branch and frozen for further study in the laboratory of the Zoology Department of the Russian State Agrarian University – Moscow Timiryazev Agricultural Academy. An incomplete helminthological dissection revealed representatives of the flatworm type at various stages of development, which were subsequently identified. The fish in the carp family, namely Abramis brama, had the highest prevalence in percentage terms.

Abstract Plastic pollution represents a threat to marine ecosystems and has therefore been gaining space in the realm of public interest. In this study, we investigated the ingestion of food and non-food items (i.e., plastic particles) by fish and crabs. These animals are commonly collected by trawling with a double-ring net along the coast of Cananéia, state of São Paulo, Brazil; some of them are consumed as food by the local population. Fish and crab stomachs were removed and dissected, and their contents were examined under a stereoscopic microscope with an image-capturing system. The presence or absence of plastic was also registered. We examined 139 specimens of 16 fish species and 143 specimens of four crab species. The most frequent food items found in fish were unidentified food, followed by crustaceans, molluscs, polychaetes, and other fish; in crabs, the items were unidentified food, followed by crustaceans, molluscs and fish. Plastic particles were found in all fish species, representing 47.5% of the individuals analysed. In crabs, the incidence of plastic was lower, occurring in only two species (5% in Callinectes danae and 3% in C. ornatus). Only four fish species analysed had previous records of plastic ingestion in the scientific literature. The high incidence of microplastics in our study is worrying because they negatively affect the animals’ lives and can be transferred through the tropic web to top predators, including humans, through the ingestion of contaminated animals.

Copyright of Brazilian Journal of Biology is the property of Instituto Internacional de Ecologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Plastic pollution represents a threat to marine ecosystems and has therefore been gaining space in the realm of public interest. In this study, we investigated the ingestion of food and non-food items (i.e., plastic particles) by fish and crabs. These animals are commonly collected by trawling with a double-ring net along the coast of Cananéia, state of São Paulo, Brazil; some of them are consumed as food by the local population. Fish and crab stomachs were removed and dissected, and their contents were examined under a stereoscopic microscope with an image-capturing system. The presence or absence of plastic was also registered. We examined 139 specimens of 16 fish species and 143 specimens of four crab species. The most frequent food items found in fish were unidentified food, followed by crustaceans, molluscs, polychaetes, and other fish; in crabs, the items were unidentified food, followed by crustaceans, molluscs and fish. Plastic particles were found in all fish species, representing 47.5% of the individuals analysed. In crabs, the incidence of plastic was lower, occurring in only two species (5% in Callinectes danae and 3% in C. ornatus). Only four fish species analysed had previous records of plastic ingestion in the scientific literature. The high incidence of microplastics in our study is worrying because they negatively affect the animals’ lives and can be transferred through the tropic web to top predators, including humans, through the ingestion of contaminated animals. [ABSTRACT FROM AUTHOR]

Microplastics are omnipresent in the marine environment. Their bioaccumulation in fish and other marine biota is a concern due to the potential human health risks from exposure through seafood sold in markets. There is a global effort afoot to take inventory of microplastic contamination in the world's main water bodies. This includes an understanding of the sources, the trophic transfer and the fate of microplastics in aquatic systems. Studies on the state of microplastic pollution in the Red Sea have appeared only in the last 5 years. Nevertheless, they gave insight into the abundance of microplastic particles within the marine environment of the Red Sea. The following is a review of these studies. [ABSTRACT FROM AUTHOR]

Abstract Amazonian commercial fishing is artisanal, and landings can be influenced by the flood pulse, the consumer market, the level of exploitation of species, habitat quality and vegetation cover. In this study, landscape variables and the river level were evaluated as possible drivers in the composition of catches landed in three regions of the Solimões-Amazon River. Fish landing data were collected in the upper and lower Solimões River and lower Amazon River. Fishing locations were mapped with information from fishers, civil defense departments and from the literature. Information related to river level and landscape was acquired from databases available online. Maps with the the radius of action of the fishing fleet and the quantification of landscape variables were made for periods of high and low-water, and non-metric multidimensional scaling analysis (nMDS) with catches by species, by region and hydrological period were performed. The largest operating radius of the fishing fleet was of 1,028 km and was identified in the lower Amazon River, which is probably due to the larger size of the consumer market, vessel characteristics and level of exploitation of the species near the landing center. The proportion of vegetation cover was reduced from 87% in the upper stretches of the Solimões River to 46% in the lower stretches. The upper and lower Solimões River regions presented a greater variety of species in the composition of landings. It was identified that the composition of landings between the three analyzed regions possibly varied according to the availability of habitats, indicating the importance of landscape variables for fish landings.

The purpose of the research is study of pinniped helminth fauna in Chukotka, and the analysis of the fish of the main commercial families infected with pathogens of helminthozoonoses based on modern literature.Materials and methods. The helminths were collected in autumn of 2019 from pinnipeds caught in the Mechigmenskaya Guba of the Bering Sea in the Chukotka Autonomous Okrug by the method of partial helminthological dissection per Skryabin (gastrointestinal tract). Samples were examined from 6 walruses and 26 seals (13 spotted seals and 13 ringed seals). The helminths found were fixed in 70% alcohol. The helminth species were identified at the Department of Parasitology and Veterinary and Sanitary Examination of the MVA named after K. I. Skryabin using reference literature.Results and discussion. All pinnipeds were infected with nematodes of the family Anisakidae. Mature Pseudoterranova desipiens were found in the walrus (Infection Prevalence = 16.7% with Infection Intensity = 3 specimens/animal), mature Ps. desipiens, as well as Contracoecum osculatum and Anisakis simplex larvae (IP = 30.8% with II from 5 to 57 specimens) were found in the spotted seal, and Ps. desipiens larvae and mature Ps. desipiens were found in the ringed seal (IP = 15.4% with II from 1 to 4 specimens). Thus, only Ps. desipiens were represented by mature stages (females and males), and two other species of anisakids, C. osculatum and A. simplex, were found in the seals in the larval stage.

The study demonstrates whether the Guanchiche of the Vinces rivers presents pathogenic bacteria of the Vibrio type, which can cause many gastrointestinal diseases. The fish were obtained directly from the sampling sites, and the physiological and nutritional status of the fish was determined through the indicators Hepatosomatic Index (IHS), Gonadosomatic Index (IGS), Condition Factor (CF), and microbiological isolation and characterization. Values referring to total length (TL) 31.48 ± 1.08 and weight 322.86 ± 23.65 as well as biological indexes such as IHS 1.23 ± 0.13; IGS of 6.28 ± 1.11 and FC of 1.08 ± 0.11 were found. Microbiologically, two Vibrio-type strains were isolated in a selective medium corresponding to Vibrio Cholerae and Vibrio parahaemolyticus; this research work is important to prevent the population from the presence of bacteria that can endanger human health. [ABSTRACT FROM AUTHOR]

Fish represent an excellent source of animal protein as well as a biomedical research model as a result of their evolutionary relatedness and similarity with the human genome. Commercial and ornamental fish culture has achieved popularity, but reproductive dysfunctions act as a limiting factor for quality fry production, interfering with the sustainability of the aquaculture industry. Fish reproduction is crucial for any species' existence, and reproductive performance can potentially be improved through applications of epigenetics and probiotics. Epigenetics is a highly sensitive molecular approach that includes chromatin structure and function alteration, DNA methylation, and modification of non-coding RNA molecules for the transfer of desired information from parents to offspring. DNA methyltransferase improves reproductive cyp11a1, esr2b, and figla gene expression and feminizes zebrafish (Danio rerio). Moreover, epigenetics also contributes to genome stability, environmental plasticity, and embryonic development. However, methylation of specific genes can negatively affect sperm quality, resulting in poor fertilization. Probiotic administration is able to induce responsiveness of incompetent follicles to maturation-inducing hormones and can change oocyte chemical composition during vitellogenic development. The positive role of probiotics on testicular cells is validated by upregulating the transcription levels of leptin, bdnf, and dmrt1 genes facilitating the spermatogenesis. This review not only discusses the effects and mechanism of epigenetics and probiotics for improving fish reproduction, but also presents an overview of the causal factors and current techniques used to eradicate dysfunction. Moreover, key genes and hormones related to fish reproduction along with research gaps and future prospects are also considered. This review provides an overview of necessary information for students, scientists, researchers, and breeders to resolve fish reproduction-related problems to ensure profitable and sustainable aquaculture. [ABSTRACT FROM AUTHOR]

The objective of changing the simple exploitation of fish stocks to highly efficient fish farms in lakes and reservoirs is to improve the productivity of inland freshwater fish. The small- and medium-sized lakes can be used to increase the production of farmed fish with lake management. Therefore, this study proposed to investigate the production and economic efficiency of carp in lake commercial fish farms. In this investigation, the results of carp farming experiments in fish farms in small lake commercial fish farms (LCFF) are evaluated using advanced methods and techniques. The research was carried out based on the Voroshilovsky reservoir, which operated in the LCFF mode. The farm had hatchery and carp fry ponds for expanding fingerlings based on the "Scientific and production center of fishery" LLP from 2019 to 2020. This study was performed on different types of common carp and herbivorous fish (grass and silver carp), and sexual products were collected in fried ponds and the Voroshilovsky reservoir. The absolute growth gain of common carp, silver carp, and grass carp were 301.00, 300.40, and 577.00 grams, respectively, and their mean daily weight gain values were 2.50, 2.50, and 4.80 grams. Common carp recorded the highest level of planned fish productivity (169.30 kg/ha), and the lowest level of this trait was grass carp (43.50 kg/ha). Data of mean weight and body length of common carp, grass carp, and silver carp fishes showed a variation of 4.55 kg and 56.25 cm, 6.06 kg and 75.50 cm, as well as 6.30 Kg and 75.05 cm, respectively. This difference can be justified according to the variance of fish length, which on average, 80 grams of weight is obtained per centimeter of fish length. The economic efficiency of carp was calculated, and the net profit was determined at more than 50% of total income. According to the net profit indicator, due to the implementation of a part of the fingerlings, the carp reared in the pond area; as a result, this method is profitable and accounts for 104% of the total planned economic profit. Therefore, fish production from aquaculture can rise to 10 times to maintain high-quality food security and other essential nutrients, provide job opportunities, and cash income to help job-seeking youth.

Given the scarcity of information suitable for stock assessments, the growth and mortality of seven exploited marine fishes in Azorean waters were estimated based on length-frequency data. The studied species were Trachurus picturatus, Sparisoma cretense, Scomber colias, Scorpaena scrofa, Serranus atricauda, Seriola spp. and Aphanopus carbo. The growth parameters L∞ (cm), k (year−1) and ϕ' estimated through the ELEFAN_GA_boot routine were set at 55.87, 0.08 and 2.39 for T. picturatus; 55.03, 0.11 and 2.53 for S. cretense; 55.93, 0.18 and 2.76 for S. colias; 61.11, 0.11 and 2.61 for S. scrofa; 52.10, 0.12 and 2.51 for S. atricauda; 107.33, 0.12 and 3.18 for Seriola spp.; and 133.16, 0.09 and 3.19 for A. carbo; respectively. The total mortality rate estimated using the length–converted catch curve method was 0.22, 0.35, 0.58, 0.32, 0.31, 0.39 and 0.22 year−1; the natural mortality included 0.15, 0.20, 0.30, 0.20, 0.21, 0.21 and 0.16 year−1; and fishing mortality rate 0.07, 0.15, 0.28, 0.12, 0.10, 0.18 and 0.06 year−1, respectively, for the species mentioned. The relatively large sizes and slow growth with a low natural mortality rate indicate a high vulnerability to overfishing. Therefore, assessment and management initiatives are highly encouraged to ensure the sustainability of the resources. [ABSTRACT FROM AUTHOR]

The article reviews the issues of forming fish populations and studying the current state of commercial fish species in the delta lakes of the Syrdarya River for subsequent effective development of fish farming. In 2020, research works were carried out on lakes Akbilek, Tushchy, Shomishkol, Karakol and Akshatau-Sorgak of Aral District of Kyzylorda Region. At each of them, local ichthyofauna were identified and studied by way of experimental catches. Subsequently, the ichthyologic material was selected, processed and underwent biological analyses. The research also included the determination of physical and geographical parameters of target lakes, as well as evaluation of their chemical water composition. Experimental and control fish catches were carried out using fixed nets with 18-60 mm cells. For biological analysis, 239 fish were selected, including: snakehead (1 sample), wild carp (3 samples), crucian carp (9 samples), roach (102 samples), pike perch (25 samples), pike (26 samples), bass (35 samples), rudd (19 samples), sabre carp (1 sample), bream (11 samples), and asp (11 samples). The suitability of target lakes for further fish husbandry use was determined based on research findings and available literature and archival data.

Fisheries management policies (FMPs) have been implemented in coastal countries to ensure a sustainable supply of seafood and the recovery of species diversity. Because of the depletion of fishery stocks, China has introduced a series of FMPs since 1995, including a seasonal fishing moratorium (SFM), a zero-growth strategy, and a minimum mesh size for fishing nets. Here, we built two mass balance models for 1997–2000 (M1997) and 2018–2019 (M2018) using Ecopath with Ecosim 6.6 to illustrate the interannual changes over the past two decades in the East China Sea (ECS). We then simulated two dynamic scenarios from 1997 to 2018, SFM (M2018SFM) and no SFM (M2018no-SFM), to test the role of the SFM under fishing pressure in the ECS. Ecopath showed that the ECS ecosystem is becoming more mature, although it is still unstable, featuring lower total primary production/total respiration, longer cycles, faster organic material circulation speed, and a higher omnivorous degree. This suggests a slow recovery for the ECS ecosystem in the past two decades. The biomass of fish in the ECS—especially the planktivores, dominated by small-sized Benthosema pterotum—significantly increased in M2018 versus M1997, but there were fewer medium- and large-sized fish. The keystone species switched from the planktivores/piscivores dominated by Decapterus maruadsi in M1997 to planktivores in M2018. Ecosim illustrated that the SFM has positive effects on fishery resources recovery, especially for commercial fishes (i.e., large yellow croakers and hairtails), as reflected by the significantly higher predicted biomass of fish in M2018SFM compared to M2018no-SFM and M1997, although the bioaccumulation was consumed by the intense fishing pressure after the SFM. However, the M2018SFM prediction for nektons was still lower than the actual value, especially for planktivores, which display a sharp increase in biomass. This should be partly attributable to the policy of the minimum mesh size (

This study aims to explore the potential health risks linked to four heavy metals/metalloids (Pb, Cd, As, Hg) present in four commercially important fish species (Scombromorus commerson, Pseudorhombus elevatus, Thunnus tonggol and Otolithes ruber) in the Persian Gulf. Metals in fish muscle tissue were analyzed via ICP-MS. The analysis revealed that Scombromorus commerson (except for Pb) and Thunnus tonggol (except for As) exhibited the highest and lowest contamination levels, respectively. The Hazard Index findings highlighted arsenic and mercury as the most hazardous elements. However, the Target Hazard Quotient values for each metal and fish species remained within safe thresholds. The highest and lowest Total Carcinogenic Risk was concerning Pseudorhombus elevates (As: 7.41-E05), and Thunnus thonggol (Pb: 3.21-E07), respectively. TCR analysis suggests that the cancer risk of studied metals was below the negligible level (TCR < 10−6) or within the acceptable level (10−6 < TCR < 10−4), potentially not posing carcinogenic risks through extended consumption. [Display omitted] • Pb and Hg exhibit the highest concentrations in the tissues of the species. • Pseudorhombus elevatus had the highest concentration of heavy metals (except for Pb). • Thunnus thonggol had the lowest concentration of heavy metals (except for As). • The highest and lowest TCR: Pseudorhombus elevatus (As: 7.41-E05), and Thunnus thonggol (Pb: 3.21-E07). [ABSTRACT FROM AUTHOR]

Dietary uptake is well known as the predominant pathway of heavy metal bioaccumulation in organisms. Our study used a typical tropical reservoir and fish as a modeling system to test the hypothesis that feeding habits and living habitats significantly affect heavy metal bioaccumulation in fish. Specifically, Cr, Mn, Fe, Ni, Cu, Zn, Cd, and Pb concentrations in water, sediment, and fish, and δ13C and δ15N in 13 fish species were detected in the Songtao Reservoir of Hainan Province, southern China. Our results indicated that Zn concentration in carnivorous fish was higher than in omnivorous fish. Principal components analysis visually differentiated pelagic, benthopelagic, and demersal fish groups. Moreover, we found that the fish feeding in the demersal habitat showed higher heavy metal levels than those in the pelagic habitat. Additionally, the heavy metal contents in demersal fish were significantly positively correlated with sediments, while no positive correlation was observed in pelagic-feeding fish. The δ15N and the concentration of Ni, Zn in fish had a significantly positive correlation, suggesting the potential biomagnification. In contrast, Ni, Fe, Cu, and Cd negatively correlated with fish body weight/length, indicating the growth dilution effects. Finally, the estimated daily intake (EDI) of the metals was far below the provisional tolerable daily intake (PTDI), and target hazard quotients (THQ) were

This paper is devoted to the construction and analysis of coupled mathematical models of hydrophysics and biological kinetics used for predicting hazardous natural phenomena occurring in shallow basins. The propagation and transformation of aquatic organisms is affected by such physical factors as three-dimensional spatial motion of water taking into account the advective transfer and microturbulent diffusion, spatially inhomogeneous distribution of temperature, salinity, and oxygen. Biogenic pollutants cause algae growth, including toxic and harmful ones; this growth can cause hazardous phenomena in the basin, including eutrophication and suffocation phenomena. A three-dimensional mathematical model of hydrodynamics is constructed and used for calculating the water flow velocity field. To investigate hazardous phenomena in a shallow basin related to suffocation phenomena in it, a three-dimensional spatially inhomogeneous ichthyological model of commercial fish dynamics is developed. Models of observations parameterized on the basis of stoichiometric relations, Monod, Michaelis–Menten, and Mitscherlich–Baule laws that describe the consumption and accumulation of nutrients by phytoplankton and commercial detritophagous fish and the growth of aquatic organisms depending on the spatial distribution of salinity, temperature, and oxygen regimen are considered. To calibrate and verify the models, constantly updated ecological databases obtained, in particular, in field research of the Sea of Azov and Taganrog Bay are used. To improve the accuracy of predictive simulation, the field data is filtered using the Kalman algorithm. As a result of processing the hydrological data, salinity and temperature isolines in the surface layer are obtained; for this purpose, a recognition algorithm is used. Using interpolation and superposition of domain boundaries, more detailed depth, salinity, and temperature maps for the Sea of Azov are obtained. Numerical methods for solving the formulated problems that are based on finite difference schemes taking into account the degree of filling of the computation domain control cells are developed. These methods are implemented on high-performance computers, and they decrease the numerical solution error and reduce the computation time by several fold. Based on the numerical implementation of the developed models, hazardous natural phenomena in shallow basins (related to the propagation of harmful pollutants), eutrophication, and algae bloom, which causes suffocation phenomena, are reconstructed. [ABSTRACT FROM AUTHOR]

Concentrations of toxic metals (Cd, Hg and Pb) in the edible tissues of seven commercial fish species (Mullus barbatus, Merlangius merlangus, Scophthalmus maximus, Mugil cephalus, Engraulis encrasicolus, Trachurus mediterraneus and Sarda sarda) collected from Sinop coasts of the southern Black Sea were detected in 11 years. In several fish samples, the concentrations of elements (Cd, Hg and Pb) were not detected or were below the detection level. The present study showed that Pb was the most and Cd was the least accumulated metal in the studied fish species. The concentrations of those metals are below the international organizations' recommended limit. It was shown that the estimated metal dose values for daily average consumption and hazarded quotients (HI) in fish samples are below safety levels for human consumption (HI˂1). From the human health point of view, this study showed that there was no possible health risk to people due to intake of any studied species under the current consumption rate in the country for 11 years. This study could be useful as a baseline data for metals exposure. [ABSTRACT FROM AUTHOR]

Information about the population structure of Conger conger (L.) is scarce, being a limiting factor for fisheries assessment. To make available important baseline information and to test the hypothesis that the population in the mid‐North Atlantic (Azores region) represents a fishery management unit, fishery‐dependent and survey data relating to bathymetric distribution, length composition and movement patterns were examined. Fishing impacts were also evaluated using abundance and size trends over the last 25 years. The greatest abundance was in depths between 300 and 600 m. Sizes ranged from 14 to 260 cm, with larger individuals around seamounts. Tagging data showed a strong sedentary behaviour. Results combined with previous genetic and otolith studies indicated the stock in the Azores may represent a self‐contained population. Abundance and size trends were stable, but the species is considered vulnerable to overfishing due to its biological characteristics. Monitoring and adequate rational resource management are of utmost importance. [ABSTRACT FROM AUTHOR]

The objective of changing the simple exploitation of fish stocks to highly efficient fish farms in lakes and reservoirs is to improve the productivity of inland freshwater fish. The small- and medium-sized lakes can be used to increase the production of farmed fish with lake management. Therefore, this study proposed to investigate the production and economic efficiency of carp in lake commercial fish farms. In this investigation, the results of carp farming experiments in fish farms in small lake commercial fish farms (LCFF) are evaluated using advanced methods and techniques. The research was carried out based on the Voroshilovsky reservoir, which operated in the LCFF mode. The farm had hatchery and carp fry ponds for expanding fingerlings based on the "Scientific and production center of fishery" LLP from 2019 to 2020. This study was performed on different types of common carp and herbivorous fish (grass and silver carp), and sexual products were collected in fried ponds and the Voroshilovsky reservoir. The absolute growth gain of common carp, silver carp, and grass carp were 301.00, 300.40, and 577.00 grams, respectively, and their mean daily weight gain values were 2.50, 2.50, and 4.80 grams. Common carp recorded the highest level of planned fish productivity (169.30 kg/ha), and the lowest level of this trait was grass carp (43.50 kg/ha). Data of mean weight and body length of common carp, grass carp, and silver carp fishes showed a variation of 4.55 kg and 56.25 cm, 6.06 kg and 75.50 cm, as well as 6.30 Kg and 75.05 cm, respectively. This difference can be justified according to the variance of fish length, which on average, 80 grams of weight is obtained per centimeter of fish length. The economic efficiency of carp was calculated, and the net profit was determined at more than 50% of total income. According to the net profit indicator, due to the implementation of a part of the fingerlings, the carp reared in the pond area; as a result, this method is profitable and accounts for 104% of the total planned economic profit. Therefore, fish production from aquaculture can rise to 10 times to maintain high-quality food security and other essential nutrients, provide job opportunities, and cash income to help job-seeking youth. [ABSTRACT FROM AUTHOR]

The article reviews the issues of forming fish populations and studying the current state of commercial fish species in the delta lakes of the Syrdarya River for subsequent effective development of fish farming. In 2020, research works were carried out on lakes Akbilek, Tushchy, Shomishkol, Karakol and Akshatau-Sorgak of Aral District of Kyzylorda Region. At each of them, local ichthyofauna were identified and studied by way of experimental catches. Subsequently, the ichthyologic material was selected, processed and underwent biological analyses. The research also included the determination of physical and geographical parameters of target lakes, as well as evaluation of their chemical water composition. Experimental and control fish catches were carried out using fixed nets with 18-60 mm cells. For biological analysis, 239 fish were selected, including: snakehead (1 sample), wild carp (3 samples), crucian carp (9 samples), roach (102 samples), pike perch (25 samples), pike (26 samples), bass (35 samples), rudd (19 samples), sabre carp (1 sample), bream (11 samples), and asp (11 samples). The suitability of target lakes for further fish husbandry use was determined based on research findings and available literature and archival data. [ABSTRACT FROM AUTHOR]

Fish is one of the most important sources of protein for human nutrition and health. Therefore, the monitoring of heavy metals accumulation in commercial fish is always important. In the present study, the accumulation of heavy metals (copper and lead) in muscle tissue and their potential hazards for consumers in three species of high-consumption fish in the south of the country (BandarAbas), namely black-spot snapper (Lutjanus ehrenbergi), javelin grunter (Pomdasys kaakan) and Indian halibut (Psettodes erumei) was examined. The average concentrations (µg/g dry weight) of copper snapper, grunter and halibut were 0.078±0.017, 0.136±0.025, and 0.127±0.013, respectively, while the accumulation of lead in them was 0.079±0.018, 0.090±023, and 0.107±0.031, respectively. The highest daily intake (µg/ kg body weight/ day) of copper was equal to 0.023 and due to consumption of grunter, while the highest daily intake of lead was obtained due to consumption of halibut and equal to 0.018. The daily and weekly intake of both metals and all three fish species was less than the EPA reference dose and tolerable intake (TDI) values provided by the FAO / WHO Joint Commission. The risk level of target hazard quotient (THQ) calculated for both metals was significantly lower than 1. The results showed that the urban communities of Hormozgan province with the calculated consumption are not exposed to any risk due to the accumulation of heavy metals studied in this study. [ABSTRACT FROM AUTHOR]

Copyright of Gestión y Ambiente is the property of Universidad Nacional de Colombia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Fish represent an excellent source of animal protein as well as a biomedical research model as a result of their evolutionary relatedness and similarity with the human genome. Commercial and ornamental fish culture has achieved popularity, but reproductive dysfunctions act as a limiting factor for quality fry production, interfering with the sustainability of the aquaculture industry. Fish reproduction is crucial for any species’ existence, and reproductive performance can potentially be improved through applications of epigenetics and probiotics. Epigenetics is a highly sensitive molecular approach that includes chromatin structure and function alteration, DNA methylation, and modification of non-coding RNA molecules for the transfer of desired information from parents to offspring. DNA methyltransferase improves reproductive cyp11a1, esr2b, and figla gene expression and feminizes zebrafish (Danio rerio). Moreover, epigenetics also contributes to genome stability, environmental plasticity, and embryonic development. However, methylation of specific genes can negatively affect sperm quality, resulting in poor fertilization. Probiotic administration is able to induce responsiveness of incompetent follicles to maturation-inducing hormones and can change oocyte chemical composition during vitellogenic development. The positive role of probiotics on testicular cells is validated by upregulating the transcription levels of leptin, bdnf, and dmrt1 genes facilitating the spermatogenesis. This review not only discusses the effects and mechanism of epigenetics and probiotics for improving fish reproduction, but also presents an overview of the causal factors and current techniques used to eradicate dysfunction. Moreover, key genes and hormones related to fish reproduction along with research gaps and future prospects are also considered. This review provides an overview of necessary information for students, scientists, researchers, and breeders to resolve fish reproduction-related problems to ensure profitable and sustainable aquaculture.

Given the scarcity of information suitable for stock assessments, the growth and mortality of seven exploited marine fishes in Azorean waters were estimated based on length-frequency data. The studied species were Trachurus picturatus, Sparisoma cretense, Scomber colias, Scorpaena scrofa, Serranus atricauda, Seriola spp. and Aphanopus carbo. The growth parameters L∞ (cm), k (year−1) and ϕ’ estimated through the ELEFAN_GA_boot routine were set at 55.87, 0.08 and 2.39 for T. picturatus; 55.03, 0.11 and 2.53 for S. cretense; 55.93, 0.18 and 2.76 for S. colias; 61.11, 0.11 and 2.61 for S. scrofa; 52.10, 0.12 and 2.51 for S. atricauda; 107.33, 0.12 and 3.18 for Seriola spp.; and 133.16, 0.09 and 3.19 for A. carbo; respectively. The total mortality rate estimated using the length–converted catch curve method was 0.22, 0.35, 0.58, 0.32, 0.31, 0.39 and 0.22 year−1; the natural mortality included 0.15, 0.20, 0.30, 0.20, 0.21, 0.21 and 0.16 year−1; and fishing mortality rate 0.07, 0.15, 0.28, 0.12, 0.10, 0.18 and 0.06 year−1, respectively, for the species mentioned. The relatively large sizes and slow growth with a low natural mortality rate indicate a high vulnerability to overfishing. Therefore, assessment and management initiatives are highly encouraged to ensure the sustainability of the resources.