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Phylosymbiosis is defined as the relationship in which the microbiome recapitulates the phylogeny of the host and has been demonstrated in a variety of terrestrial organisms, although it has been understudied in fish, the most phylogenetically diverse vertebrate. Given that the species-specificity of fish microbiomes was detected in multiple body parts and differed by body parts, we assumed that the phylogenetic reflection of the microbiome would differ across body parts. Thus, we analyze the difference of phylosymbiotic relationships in the microbial communities found in three body parts (skin, gills, and intestine) of seven wild fish species from four families (Labridae, Sebastidae, Sparidae, and Rajidae) via 16S rRNA gene amplicon sequencing. Fishes were purchased at Docheon port market in Tongyeong City, Korea and were transported to nearby research institutes for aliveness. Mantel tests using dissimilarity values of microbiomes and hosts' divergence times showed that the differences in microbial communities in all three body parts were related to the hosts' divergence time. This pattern was the most pronounced in the skin. Furthermore, fishes from the same family showed similar bacterial compositions on their skins and gills, with clear differences depending on the family, with the exception of Labridae. These results suggest that the skin microbiome is particularly vulnerable to evolutionary pressures. We hypothesized that the evolution of the fish immune system and the difference in feeding habits induced the stronger phylosymbiotic signal in the skin. Collectively, this dataset will be useful for understanding the fish microbiome and give insights into phylosymbiosis of aquatic animals across body parts. [ABSTRACT FROM AUTHOR]

Given the influence of cage fish farms and the relevance of considering the inter-individual variation in the diet, we aimed to evaluate the dietary aspects of Geophagus sveni under the influence of cage fish farms in a neotropical reservoir at the individual level. To test the hypothesis that cage fish farms promote changes in the use of food resources at the individual level, we investigated the diet of two groups of G. sveni, one group under the influence of cage fish farms and another group without this influence. We observed that the group's diet composition differed between the sampling areas due to the consumption of pelleted feed and reduced consumption of other items, such as invertebrates and plants, in the cage farm area. At the individual level, we observed specialist individuals in both sampling areas. This individual specialization may indicate that few individuals consumed a large volume of the pelleted feed, which was masked when assessing the group's diet. We also observed that pelleted feed was an additional food item, and we suggest that this availability contributed to individual specialization in the cage farm area. In a general context, we also suggest that due to this supply of an additional highly energetic food item, cage fish farms may be favoring the success of the introduced species. Thus, we emphasize the need for individual evaluations in ecological studies, especially in assessing human-caused effects. [ABSTRACT FROM AUTHOR]

The gut microbiota plays a crucial role in various physiological functions of the host and can be modulated by numerous factors, including feeding habit or trophic level. In this study, the impact of host feeding habits on the gut microbiota of freshwater fish was explored. Ten fish species, classified into four feeding habit categories (herbivorous, omnivorous, planktivorous, and carnivorous) were sampled from West Lake, a renowned urban scenic lake, and their gut content microbiota was analysed using 16S ribosomal RNA gene sequencing. A total of 2531 operational taxonomic units, belonging to 34 bacterial phyla, were identified, with 33.4% shared across all feeding habits. Firmicutes and Proteobacteria were the predominant phyla. However, at the family level, Peptostreptococcaceae and Clostridiaceae_1 were the most dominant. Microbiota composition diversity was highest in herbivorous fish, followed by omnivores, carnivores, and planktivores. Statistically significant differences in microbiota diversity were found between different feeding categories, except for the omnivores, which did not differ from the carnivores or planktivores. The most abundant predicted metabolic pathways across all feeding habits were similar, with amino acid metabolism, carbohydrate metabolism, metabolism of cofactors and vitamins, and metabolism of other amino acids being dominant. However, comparing the relative abundance of gene functions between different feeding habits revealed notable variations across most comparisons. Co‐occurrence network analysis for each feeding habit revealed that all networks were dominated by the strong positive correlation among pairs of bacterial genera abundances, while the basic properties varied, implying differences in gut microbiota interactions based on the feeding habit. In conclusion, these results confirmed that the feeding habit could affect the structure and composition of the gut content microbiota but also changed their functions and interactions. [ABSTRACT FROM AUTHOR]

Trace elements generally contaminate wild fish, particularly in megacities, necessitating guided consumption practices. This study investigated the bioaccumulation of trace elements in wild fish from Chongqing City in June 2021. We evaluated their contamination and associated health risks to establish consumption guidance based on fish size. Our results indicate that the concentrations of Zn, Pb, Cr, and As were relatively high, with some fish exceeding the maximum residue limits. Herbivorous and pelagic fish generally exhibited lower bioaccumulation of most trace elements, except for Cr and As, which were higher in pelagic species. The contamination indices (Pi) for Cr, Pb and As were consistently above 0.2, indicating widespread contamination. The most contaminated fish typically measured around 19 cm in length and weighed approximately 90 g. Only the maximum target hazard quotients (THQ) for As, Cr, and Hg exceeded 1, with a notably high ratio of THQ(As) > 1, highlighting concerns over arsenic contamination. The THQ(As) remained below 1 for adults across all fish species, whereas for children, species such as Onychostoma sima, Pseudohemiculter dispar, and Parabramis pekinensis exceeded this threshold. Fish safe for adult consumption generally measured 13 cm in length and weighed 20 g, and for children, 16 cm and 25 g. Consequently, selecting larger fish is likely to reduce the consumption of contaminated fish, thereby decreasing health risks to the public. The centralization of contaminated fish with high risk in specific size range confirmed fish size could be used to gauge the contamination and health risk of fish. [ABSTRACT FROM AUTHOR]

The article in the Journal of Fish Diseases discusses the prevalence and typology of skeletal abnormalities in fish from the Eastern Mediterranean. The study reports on various types of skeletal abnormalities found in specimens of 10 fish species from the Aegean Sea, with rates ranging from 3.3% to 28.6%. The research highlights the impact of anthropogenic pressures, pollution, and other factors on the occurrence of skeletal abnormalities in wild fish populations. The study emphasizes the need for further monitoring programs to understand the effects of fish abnormalities on natural stocks and mortality rates. [Extracted from the article]

Sentiment analysis, a form of data analytics, utilises information from online discussions, reviews, and social media posts to assess consumer sentiments. This study utilised data collected from social media using online listening procedures to assess online sentiments on oysters from January 2019 through December 2022. The analysis utilises machine learning algorithms to extract consumer sentiments, opinions, and demands from online chatter from different online domains. The online sentiments are determined as positive, negative, or neutral based on their word choice, tone, and context. The information provided gives insights into perception, which is valuable information for oyster producers, seafood industry stakeholders, and marketers to identify consumer preferences and formulate appropriate strategies accordingly. The results suggest that while farmed oysters are gaining popularity, there are still some concerns and criticisms around the industry. Positive words associated with mentions of oysters in general include 'great', 'love', 'delicious', 'enjoyed', and 'oyster bar', while negative words associated with oysters include 'water', 'raw oyster', 'bad', and 'not eat'. The overall percentage net sentiment associated with all oysters in the United States is positive at 63%. The net sentiment associated with wild oysters is positive, at 51%, and that of farmed oysters is 58%. The oyster industry could invest more in public education, sustainability, and water‐cleaning initiatives to improve its image. Utilising social media to monitor and shape public perception can help the industry address concerns and enhance oyster‐related sentiments, offering valuable insights for marketing and sales strategies. [ABSTRACT FROM AUTHOR]

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Plastic products are widely used in human daily life, while facilitating human life, plastics have also produced many negative effects due to the lack of effective recovery measures, plastic pollution has become an important environmental issue of global concern. Marine plastics can be degraded into smaller microplastics (MPs) through various ways under the influence of environmental factors. They can be ingested by marine organisms mixed with food sources, and then accumulated in the body, causing serious negative effects on marine lifes and marine ecology. Recently, it has been proved that the Changshan Islands sediments contain a certain amount of MPs, the content reached 133.14 to 499.82 n/kg. Changshan Islands is one of the eight major islands in China. It is located at the confluence of the Yellow Sea and the Bohai Sea, and has a unique geographical location. The fish community between the islands is rich in species, especially in many migratory species, and high in species diversity. The seasonal change of fish species composition and dominant species is obvious. It has been proved MPs can cause a certain degree of harm to marine organisms. Therefore, the distribution of MPs in organisms in the Changshan Islands sea area deserves to be studied. In this study, the MPs in the gastrointestinal tracts and muscles of wild fish were digested and separated after collecting them from the marine culture zone of Changshan Islands. The results showed that MPs were detected existing in the gastrointestinal tracts of all fish, but not in muscle tissues. The reason may be that MPs are too large to be endocytosed by intestinal epithelial cells, and thus can not participate in the blood circulation of fish. The abundance of MPs in the gastrointestinal tracts of seven species of marine wild fish ranged from 0.19 to 3.79 items/individual. The abundance of MPs in Coilia nasus is the highest among all fish, this phenomenon may be related to the living environment and predation habits of C. nasus, which living in the bottom of the sea. The MPs in sediments will undergo a cyclic process of suspension, sedimentation and resuspension under the flow of seawater, thus greatly increasing the exposure and intake risk of MPs by bottom organisms, such as C. nasus. The shape of MPs was dominated by the fiber, and the color was mostly transparent, which size is mainly less than 300 μm. The reason may be that the individual size of fish collected in this survey is small, and larger-sized MPs cannot enter into the gastrointestinal tract of fish through feeding. Large plastics in the environment are broken under the photooxidation, wave action, physical wear and alternating freeze-thaw. The different shapes of MPs detected in this study may be derived from the decomposition of these large plastics. Fibers are the predominant form of MPs encountered in global wildlife studies. It could also be because fibrous MPs are the most abundant in the marine environment. Additionally, MPs Fibers can be bended or intertwined with food, possibly due to long-term accumulation for the slower fibers excretion, increasing the chance of being ingested by organisms. The types of polymers detected were cellophane, cellulose and polyethylene, among which cellophane had the highest content. Cellophane is an organic cellulose-based polymer that has been used in food packaging and cigarette packaging. It is also used as a release agent in the manufacture of glass fiber and rubber products, or as a coating in combination with synthetic polymers. There was no obvious toxic effect on cellulose and cellulite. The polymer hazard index (PHI) is an important criterion for risk assessment of MPs, and is based primarily on the percentage content of a given polymer and the polymer's hazard fraction for ecological and health risk assessment. The potential risk of MPs to humans can be estimated by the polymer hazard index. The higher the polymer hazard index, the higher the ecological risk in the sea area. The toxicity coefficient of polyethylene is 10, the toxicity grade is grade II, the hazard index is low, and it belongs to the low risk polymer. Moreover, people usually discard the gastrointestinal tract of fish before eating, thus the MPs in the fishes of Changshan Islands, and the safety factor of fish products in Changshan Islands is higher. In this study, through the collection of wild fish in Changshan Islands, the MPs in gastrointestinal tract and muscle tissue were extracted, and the abundance and type of MPs were analyzed. The pollution status of MPs in fish in the adjacent waters of Changshan Islands was clarified, which provided basic data for exploring the impact of MPs on the ecological environment safety of Changshan Islands ecosystem. Further research on the distribution of MPs in other wild organisms, such as shellfish, and in other economically viable locations should be considered, which can provide a scientific basis for the analysis of MP pollution levels and the formulation of prevention and control strategies in the marine environment.

Nematodes that parasitize salmonids are found in both seawater and freshwater. Unlike seawater species such as those in family Anisakidae, freshwater species have not been well studied. In particular, the influences of these nematodes on the body condition of salmonids remain unclear. We studied the effects of Salmonema cf. ephemeridarum on the body condition of masu salmon Oncorhynchus masou. We found a positive relationship between the number of parasites and fish fork length. In contrast, we found a negative relationship between the body condition (condition factor) of fish and the number of parasites. These results suggest that nematode infection could affect host energy reserves for future growth. [ABSTRACT FROM AUTHOR]

The gut microbiota of fish is crucial for their growth, development, nutrient uptake, physiological balance, and disease resistance. Yet our knowledge of these microbial communities in wild fish populations in their natural ecosystems is insufficient. This study systematically examined the gut microbial communities of seven wild fish species in Chaohu Lake, a fishing-restricted area with minimal water turnover, across four seasons. We found significant variations in gut microbial community structures among species. Additionally, we observed significant seasonal and regional variations in the gut microbial communities. The Chaohu Lake fish gut microbial communities were predominantly composed of the phyla Firmicutes, Proteobacteria(Gamma), Proteobacteria(Alpha), Actinobacteriota, and Cyanobacteria. At the genus level, Aeromonas, Cetobacterium, Clostridium sensu stricto 1, Romboutsia, and Pseudomonas emerged as the most prevalent. A co-occurrence network analysis revealed that C. auratus, C. carpio, and C. brachygnathus possessed more complex and robust gut microbial networks than H. molitrix, C. alburnus, C. ectenes taihuensis, and A. nobilis. Certain microbial groups, such as Clostridium sensu stricto 1, Romboutsia, and Pseudomonas, were both dominant and keystone in the fish gut microbial network. Our study offers a new approach for studying the wild fish gut microbiota in natural, controlled environments. It offers an in-depth understanding of gut microbial communities in wild fish living in stable, limited water exchange natural environments. [ABSTRACT FROM AUTHOR]

Abstract Sentiment analysis, a form of data analytics, utilises information from online discussions, reviews, and social media posts to assess consumer sentiments. This study utilised data collected from social media using online listening procedures to assess online sentiments on oysters from January 2019 through December 2022. The analysis utilises machine learning algorithms to extract consumer sentiments, opinions, and demands from online chatter from different online domains. The online sentiments are determined as positive, negative, or neutral based on their word choice, tone, and context. The information provided gives insights into perception, which is valuable information for oyster producers, seafood industry stakeholders, and marketers to identify consumer preferences and formulate appropriate strategies accordingly. The results suggest that while farmed oysters are gaining popularity, there are still some concerns and criticisms around the industry. Positive words associated with mentions of oysters in general include ‘great’, ‘love’, ‘delicious’, ‘enjoyed’, and ‘oyster bar’, while negative words associated with oysters include ‘water’, ‘raw oyster’, ‘bad’, and ‘not eat’. The overall percentage net sentiment associated with all oysters in the United States is positive at 63%. The net sentiment associated with wild oysters is positive, at 51%, and that of farmed oysters is 58%. The oyster industry could invest more in public education, sustainability, and water‐cleaning initiatives to improve its image. Utilising social media to monitor and shape public perception can help the industry address concerns and enhance oyster‐related sentiments, offering valuable insights for marketing and sales strategies.

In order to determine the status of heavy metal pollution in river sediments and wild fish in Xi'an, concentrations of heavy metals (Cr, Ni, Cu, Zn, As, and Pb) were collected and analyzed in sediments and wild fish during dry season (October–November 2020) and wet season (June–July 2021). This study aimed to investigate the spatial and temporal variations of heavy metals in urban rivers of Xi'an, China. Their distribution characteristics and sources as well their pollution levels and health risks were assessed. The findings revealed that influenced by human activities, the heavy metal content in sediments (mg·kg−1 dry weight) in wet season was ranked as follows: Cr (73.09) > Zn (63.73) > Pb (40.31) > Ni (31.52) > Cu (24.86) > As (6.83); in the dry season: Zn (94.07) > Cr (69.59) > Cu (34.24) > Ni (33.60) > Pb (32.87) > As (7.60). Moreover, 32 fish samples from six species indicated an average metal content trend (mg·kg−1 wet weight) of Zn (8.70) > Cr (0.57) > Pb (0.28) > Ni (0.27) > Cu (0.24) > As (0.05). The potential ecological risk indices for sediment heavy metal concentrations in both seasons were well below the thresholds, which indicates that the aquatic environment is in safe level. The analysis of the potential ecological risk of sediment heavy metal concentrations indicates that the aquatic environment is safe for the time being. Based on the estimated daily intake (EDI), target risk quotient (THQ), total target risk quotient (TTHQ), cancer risk (CR), total cancer risk (TCR), and the permissible safety limits set by the agencies, the consumption of the fish examined is safe for human health. However, the presence of Cr and As in wild fish should still be a concern for human health, especially for children. The cumulative effect of heavy metals and the bioconcentration factor (BCF) suggest that sediment and heavy metals in fish are closely related, with higher concentrations in fish living in the bottom layer of the water column than in other water layers, and increasing with increasing predator levels. Correlation analysis and PMF modeling identified and determined four comparable categories of potential sources, namely, (1) atmospheric deposition and traffic sources, (2) agricultural sources, (3) industrial sources, and (4) natural sources. [ABSTRACT FROM AUTHOR]

Objective: To measure vitamin D status and estimate factors associated with serum 25-hydroxyvitamin D (25(OH)D) in Nunavimmiut (Inuit living in Nunavik) adults in 2017. Design: Data were from Qanuilirpitaa ? 2017 Nunavik Inuit Health Survey, a cross-sectional study conducted in August–October 2017. Participants underwent a questionnaire, including an FFQ, and blood samples were analysed for total serum 25(OH)D. Setting: Nunavik, northern Québec, Canada. Participants: A stratified proportional model was used to select respondents, including 1,155 who identified as Inuit and had complete data. Results: Geometric mean serum vitamin D levels were 65·2 nmol/l (95 % CI 62·9–67·6 nmol/l) among women and 65·4 nmol/l (95 % CI 62·3–68·7 nmol/l) among men. The weighted prevalence of serum 25(OH)D < 75 nmol/l, <50 nmol/l <30 nmol/l was 61·2 %, 30·3 % and 7·0 %, respectively. Individuals who were older, female, lived in smaller and/or more southerly communities and/or consumed more country (traditional) foods were at a reduced risk of low vitamin D status. Higher consumption of wild fish was specifically associated with increased serum 25(OH)D concentration. Conclusion: It is important that national, regional and local policies and programs are in place to secure harvest, sharing and consumption of nutritious and culturally important country foods like Arctic char and other wild fish species, particularly considering ongoing climate change in the Arctic which impacts the availability, access and quality of fish as food. [ABSTRACT FROM AUTHOR]

Abstract Objective: To measure vitamin D status and estimate factors associated with serum 25-hydroxyvitamin D (25(OH)D) in Nunavimmiut (Inuit living in Nunavik) adults in 2017. Design: Data were from Qanuilirpitaa? 2017 Nunavik Inuit Health Survey, a cross-sectional study conducted in August–October 2017. Participants underwent a questionnaire, including an FFQ, and blood samples were analysed for total serum 25(OH)D. Setting: Nunavik, northern Québec, Canada. Participants: A stratified proportional model was used to select respondents, including 1,155 who identified as Inuit and had complete data. Results: Geometric mean serum vitamin D levels were 65·2 nmol/l (95 % CI 62·9–67·6 nmol/l) among women and 65·4 nmol/l (95 % CI 62·3–68·7 nmol/l) among men. The weighted prevalence of serum 25(OH)D < 75 nmol/l,

The proximate composition, amino acid, fatty acid and mineral elements of wild and farmed Conger myriaster muscle were compared. Results indicated that the lipid content of farmed fish was significantly higher, while moisture content was significantly lower than that of the wild fish (P<0.05). The contents of all essential amino acids (EAA), half essential amino acids (HEAA) and Tyr, Asp, Glu were significantly higher in farmed Conger myriaster than that in wild fish (P<0.05). The ratios of the WEAA/WTAA (39.92% vs 39.77%) and WEAA/WNEAA (84.29% vs 82.37%) were similar in farmed and wild Conger myriaster (P>0.05). n-3 polyunsaturated fatty acids (PUFAs), n-6 PUFAs and total PUFAs content were lower in wild than that in farmed Conger myriaster (P<0.05). Docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) were higher in farmed than wild Conger myriaster (P<0.05). Farmed fish showed significant high content in K and Mg but low in Hg, As and Pb compared to wild fish (P<0.05). In a word, farmed Conger myriaster under investigation have high nutritional qualities and positive health benefits, it is a potentially healthier alternative to the wild Conger myriaster. [ABSTRACT FROM AUTHOR]

The gut microbiota of fish is crucial for their growth, development, nutrient uptake, physiological balance, and disease resistance. Yet our knowledge of these microbial communities in wild fish populations in their natural ecosystems is insufficient. This study systematically examined the gut microbial communities of seven wild fish species in Chaohu Lake, a fishing-restricted area with minimal water turnover, across four seasons. We found significant variations in gut microbial community structures among species. Additionally, we observed significant seasonal and regional variations in the gut microbial communities. The Chaohu Lake fish gut microbial communities were predominantly composed of the phyla Firmicutes, Proteobacteria(Gamma), Proteobacteria(Alpha), Actinobacteriota, and Cyanobacteria. At the genus level, Aeromonas, Cetobacterium, Clostridium sensu stricto 1, Romboutsia, and Pseudomonas emerged as the most prevalent. A co-occurrence network analysis revealed that C. auratus, C. carpio, and C. brachygnathus possessed more complex and robust gut microbial networks than H. molitrix, C. alburnus, C. ectenes taihuensis, and A. nobilis. Certain microbial groups, such as Clostridium sensu stricto 1, Romboutsia, and Pseudomonas, were both dominant and keystone in the fish gut microbial network. Our study offers a new approach for studying the wild fish gut microbiota in natural, controlled environments. It offers an in-depth understanding of gut microbial communities in wild fish living in stable, limited water exchange natural environments.

Native species are important to the dynamics of aquatic environments. Studies that seek to understand the basic biology of these species provide information on the species and the dynamics of the natural environment. We characterized the diet, feeding habits, and trophic niche breadth of the native species Hoplosternum littorale (Hancock, 1828) in neotropical lentic environments. Collections were carried out in July 2018 at two sampling points (lagoons) located in the São Francisco Falso River and the Corvo River using gill nets. Stomach content was analyzed, and food items were separated, identified, and quantified using the volumetric method. PERMANOVA analysis was performed to evaluate possible differences in diet between the lagoons. Furthermore, PERMDISP was used to test the trophic niche breadth. Fifteen food items were recorded in the São Francisco lagoon, with the most consumed items being detritus, Diptera (larvae and pupa), and Odonata (nymph). Seven food items were recorded in the Corvo lagoon, with detritus being the most consumed. There was no difference in diet composition and trophic niche breadth between the evaluated lagoons. For both lagoons studied, the species was determined to be a detritivore feeding habit, given its diet's predominant consumption of detritus. The detritivore classification may be related to environmental conditions, food availability, and functional morphology. We also observed the presence of microplastics in the stomachs of some specimens, demonstrating anthropic influence on aquatic environments. Our study contributes to bettering knowledge on this species, and consequently the conservation of the species. It can also serve as a basis for conducting future scientific studies, along with developing the area of study related to Brazilian fish ecology.

The Atlantic salmon (Salmo salar) population in the Baltic Sea consists of wild and hatchery-reared fish that have been released into the sea to support salmon stocks. During feeding migration, salmon migrate to different parts of the Baltic Sea and are exposed to various biotic and abiotic stressors, such as organohalogen compounds (OHCs). The effects of salmon origin (wild or hatchery-reared), feeding area (Baltic Main Basin, Bothnian Sea, and Gulf of Finland), and OHC concentration on the differences in hepatic proteome of salmon were investigated. Multi-level analysis of the OHC concentration, transcriptome, proteome, and oxidative stress biomarkers measured from the same salmon individuals were performed to find the key variables (origin, feeding area, OHC concentrations, and oxidative stress) that best account for the differences in the transcriptome and proteome between the salmon groups. When comparing wild and hatchery-reared salmon, differences were found in xenobiotic and amino acid metabolism-related pathways. When comparing salmon from different feeding areas, the amino acid and carbohydrate metabolic pathways were notably different. Several proteins found in these pathways are correlated with the concentrations of polychlorinated biphenyls (PCBs). The multi-level analysis also revealed amino acid metabolic pathways in connection with PCBs and oxidative stress variables related to glutathione metabolism. Other pathways found in the multi-level analysis included genetic information processes related to ribosomes, signaling and cellular processes related to the cytoskeleton, and the immune system, which were connected mainly to the concentrations of Polychlorinated biphenyls and Dichlorodiphenyltrichloroethane and their metabolites. These results suggest that the hepatic proteome of salmon in the Baltic Sea, together with the transcriptome, is more affected by the OHC concentrations and oxidative stress of the feeding area than the origin of the salmon.

A total of 151 wild and farmed fish samples of three species (S. aurata, D. labrax and U. cirrosa) from south Mediterranean were examined for cadmium, lead and mercury and total lipids detection to verify possible differences between wild and farmed fish. Mercury was detected only in S. aurata samples, with mean values of 0.056 ± 0.128 mg/kg and 0.031 ± 0.033 mg/kg for farmed and wild samples, respectively. The results verified no significant differences in Pb, Cd and Hg levels between wild and farmed fish samples (p < 0.05). The farmed fish samples showed higher total lipids contents than wild (p > 0.05). As far as we know, this work report first findings on the toxic metal presence in farmed Umbrina cirrosa, showing no detectable Hg, Cd and Pb values. The results of this work seems to confirm that the presence of toxic metals could be more related to the pollution the site than the type of production. [ABSTRACT FROM AUTHOR]

In today's world, microplastic contamination of aquatic systems is a subject of major concern. In this study, the incidence of microplastics in freshwater fish from both farmed and wild sources was evaluated. Wild catla (Gibelion catla), stinging catfish (Heteropneustes fossilis), rui (Labeo rohita), tengara catfish (Mystus tengara), and pabdah catfish (Ompok pabda) were collected from Padma River, Turag River, and Bhairab River. Farmed fishes of same species were collected from Mymensingh and Chandpur fish markets. A total of 68 (43.6%) microparticles out of 156 were identified as microplastics using ATR-FTIR. About 66.67% (20 out of 30) of farmed fish samples had microplastics in their digestive system, while 88.4% (23 of 26) of wild fish samples presented microplastics. There was a significant difference (p < 0.05) in average microplastic count between wild and farmed fish. Average microplastic count also showed a significant difference among five fish species (p < 0.01). A variety of polymers were observed, with polyethylene being the most abundant, followed by polyester, polypropylene, polyamide-6, and polyurethane. This study suggests that microplastic contamination is ubiquitous and contamination is common in all of the fish species investigated, independent of their origin (wild or farmed). However, wild fish population is at a greater risk of ingesting microplastics. This study, for the first time ever, reports plastic pollution in freshwater fishes of Bangladesh from wild and farmed sources. [ABSTRACT FROM AUTHOR]

Reliable stock identification constitutes an integral component of effective fishery management. Current methods for the identification of putative stock units comprise the analysis of both phenotypic and genetic variability. The present study examined the spatial variation in otolith morphology (shape and asymmetry) and genetic composition of 395 wild-caught Gilthead seabream (Sparus aurata) specimens, collected from the Aegean and Ionian Seas (eastern Mediterranean) between 2014–2018. The degree of scale regeneration (SRD, % of regenerated scales) was used as an indicator to assess the potential presence of aquaculture escapees in the wild-caught samples. Otolith shape and asymmetry analyses showed a phenotypic discrimination between northwestern Aegean and Ionian Gilthead seabream populations. Genetic analyses of nine microsatellite markers revealed higher levels of genetic variation in the wild compared with samples obtained from aquaculture farms. Despite the absence of genetic structure among the wild-caught seabream populations, a low but statistically significant genetic differentiation was found between reared fish and fish collected in the field. The SRD was considered effective in detecting the presence of aquaculture escapees that may have escaped in either early or late rearing phases. [ABSTRACT FROM AUTHOR]

Mycobacterium infection in fish is a well‐known disease problem globally, mainly in the farming of ornamental fish or fish for food. Less is known about the prevalence, distribution and the effects such infections have on wild fish species. Presumptive mycobacteriosis has previously been observed in Atlantic mackerel (Scomber scombrus). Since 2018, there has been an increase in reports of granulomatous kidney disease in Atlantic mackerel with the suspicion of this being mycobacteriosis. A total of six individuals were sent to the Institute of Marine Research for further examination. They were caught in the Nordic Sea by either commercial fishing vessels or during the International Ecosystem Summer Survey in the Nordic Seas (IESSNS research cruise) between 2018 and 2020. Samples for both histological and molecular analysis were collected. Here, we detect a likely novel Mycobacterium species in tissue samples from Atlantic mackerel with this condition, on the basis of rDNA and protein gene sequences. The same unnamed bacterium seems to have been found in some Pacific marine fishes. The macroscopic and histological manifestation of the disease is described. Over the past years, there has been an increase in reports of mycobacteriosis worldwide and climate change has been suggested as one of the driving forces as these bacteria prefer warm water. [ABSTRACT FROM AUTHOR]

The mass production of fish in a developing country like Bangladesh has ensured food security with quality of fish hardly. The purpose of this study thus is to identify the implicit price of the fish quality characteristics. In total, 200 consumers were randomly interviewed from three different coastal districts of Bangladesh where both farmed and wild fish were available. The consumers were interviewed using a semi-structured questionnaire during their purchase and the semi-log functional form of regression model was applied to explore the implicit price of the fish quality characteristics. The findings indicated that consumers' high payment (at least 61% price premium) on wild fish for its taste, size, and eye character. However, it was found that consumers preferred farmed fish for its freshness and bright color while they disfavored swollen abdomen and odor. The results also revealed that consumers paid 18% more for the farmed fish freshness and 9% less for the fish with odor and swollen abdomen. It was also noticed that quantity of the fish and presence of bones were the influential factors of reducing the price of both fish. The study implies that fish farmers need to produce fish considering quality characteristics rather than producing more since good food ensures good health. The study refers to the implementation of the 'Government Fishery Act' for increasing the wild fish stock including different small indigenous species, catfish, and hilsha for consumers' demands and preferences. [ABSTRACT FROM AUTHOR]

Crude electronic waste (e-waste) recycling has been banned due to the serious environmental pollution it caused, leaving many abandoned e-waste sites. However, information on the current levels and associated ecological risks of e-waste-derived contaminants such as polychlorinated biphenyls (PCBs) in e-waste site is limited. Wild fish, because they can accumulate high pollutant levels, are suitable indicators for environmental pollution monitoring and has been widely employed as biomonitoring. In this study, we investigated the changes in the levels and profiles of PCBs in a wild fish species, the northern snakehead (Channa argus), before (2009) and after (2016) the ban of crude e-waste recycling from a typical e-waste recycling site in South China. The mean total PCB concentration in the northern snakehead sampled in 2016 (343 ng/g ww) declined by 75% compared with that (1410 ng/g ww) in 2009. The contributions of less chlorinated congeners (tri-CBs and tetra-CBs) in the northern snakehead tended to decrease over the years, indicating that the lighter congeners are more easily eliminated than the heavier ones in the environment. Our findings suggested no fresh PCB input in these years, as well as the positive impacts of laws and regulations on the prohibition of e-waste recycling. The ecological risk assessment suggested that PCB exposure may have median to high risks to the wild fish and fish-eating wildlife that inhabit the e-waste site, even after the ban of crude e-waste recycling activities. [ABSTRACT FROM AUTHOR]

Native species are important to the dynamics of aquatic environments. Studies that seek to understand the basic biology of these species provide information on the species and the dynamics of the natural environment. We characterized the diet, feeding habits, and trophic niche breadth of the native species Hoplosternum littorale (Hancock, 1828) in neotropical lentic environments. Collections were carried out in July 2018 at two sampling points (lagoons) located in the São Francisco Falso River and the Corvo River using gill nets. Stomach content was analyzed, and food items were separated, identified, and quantified using the volumetric method. PERMANOVA analysis was performed to evaluate possible differences in diet between the lagoons. Furthermore, PERMDISP was used to test the trophic niche breadth. Fifteen food items were recorded in the São Francisco lagoon, with the most consumed items being detritus, Diptera (larvae and pupa), and Odonata (nymph). Seven food items were recorded in the Corvo lagoon, with detritus being the most consumed. There was no difference in diet composition and trophic niche breadth between the evaluated lagoons. For both lagoons studied, the species was determined to be a detritivore feeding habit, given its diet's predominant consumption of detritus. The detritivore classification may be related to environmental conditions, food availability, and functional morphology. We also observed the presence of microplastics in the stomachs of some specimens, demonstrating anthropic influence on aquatic environments. Our study contributes to bettering knowledge on this species, and consequently the conservation of the species. It can also serve as a basis for conducting future scientific studies, along with developing the area of study related to Brazilian fish ecology. [ABSTRACT FROM AUTHOR]

This study argued for the first time that 6:2 chlorinated polyfluorinated ether sulfonate (6:2 Cl-PFESA) and perfluorooctanesulfonic acid (PFOS) might have different tissue distribution mechanisms in wild fish species. Nine emerging and legacy per- and polyfluoroalkyl substances (PFASs) were detected in the water and wild fish tissues samples collected from the Qiantang River. Perfluorooctanoic acid (213 ng/L) was the predominant PFAS contaminant, and the other contaminants included perfluorohexanoate (19 ng/L), perfluorobutanoate (199 ng/L) and hexafuoropropylene oxide dimer acid (55 ng/L), which are the main fluorinated alternatives used in various industries located along the Qiantang River. Furthermore, PFOS (742 ng/g) and 6:2 Cl-PFESA (9.0 ng/g) were the predominant PFAS contaminants detected in the fish tissue samples. The differences in the potential molecular mechanism of the tissue distribution of PFOS and 6:2 Cl-PFESA in wild fish species are discussed. Additionally, we hypothesize that phospholipid partitioning is the primary mechanism underlying the tissue distribution of PFOS, and that a specific protein-binding mechanism is involved in the tissue distribution of 6:2 Cl-PFESA. [Display omitted] • HFPO-DA and 6:2 Cl-PFESA are perfluorinated alternatives of concern in water samples and fish tissue samples, respectively. • Tissue distribution of individual PFASs shows structure-related. • Molecular mechanisms underlying the tissue distribution of PFOS and 6:2 Cl-PFESA differ. • The bioaccumulation potential of 6:2 Cl-PFESA in the heart, spleen, and liver of fish is higher than that of PFOS. [ABSTRACT FROM AUTHOR]

Pollution-induced neurotoxicity is of high concern. This pilot study investigated the potential relationship between the presence of microplastics (MPs) in the brain of 180 wild fish (Dicentrarchus labrax, Platichthys flesus, Mugil cephalus) from a contaminated estuary and the activity of the acetylcholinesterase (AChE) enzyme. MPs were found in 9 samples (5% of the total), all of them from D. labrax collected in the summer, which represents 45% of the samples of this species collected in that season (20). Seventeen MPs were recovered from brain samples, with sizes ranging from 8 to 96 μm. Polyacrylamide, polyacrylic acid and one biopolymer (zein) were identified by Micro-Raman spectroscopy. Fish with MPs showed lower (p ≤ 0.05) AChE activity than those where MPs were not found. These findings point to the contribution of MPs to the neurotoxicity induced by long-term exposure to pollution, stressing the need of further studies on the topic to increase ‘One Health’ protection.

Understanding the spatial distribution patterns of microplastics (plastics < 5 mm) contributes to the assessment of sources and sinks of pollution thus providing information for the management of biota safety and overall ecosystem functionality. We chose a semi-closed study area, Lake Bracciano (Italy), to assess the environmental variability of contamination, focusing on the water compartment and the exposure of biota, specifically fish, by analysing the ingestion of microplastics. The focus of this study is to evaluate the concentration of microplastics in water (surface and column) across the lake and the ingestion of microplastics by two fish species of economic interest: Atherina boyeri and Coregonus lavaretus, inhabiting demersal and pelagic habitats respectively. Results show a surface contamination of 392,000 ± 417,000 items km−2 and a column one of 0.76 ± 1.00 items m−3. Fragments were the most abundant in surface while fibres in the column. Microplastics were found in C. lavaretus specimens, corresponding to contamination frequency of 5% and concentration of 0.15 items/fish. The main polymer found in water was polyethylene (81%); of minor percentages, there were various other polymers, including polystyrene and acrylic, which were also found in fish. As scientific literature provides few research where water and fish are simultaneously sampled, this investigation wants to contribute filling this knowledge gap by investigating for the first time a volcanic lake. [ABSTRACT FROM AUTHOR]

Globally, both natural water bodies and aquaculture systems are being severely contaminated by heavy metals due to rising anthropogenic activities. Fish living in aquatic environments can easily accumulate metals in their bodies, which can then be transferred to consumers and put them at risk. In this study, metal concentrations (Pb, Cd, Cr, As, Mn, Cu, Zn) in different organs (gill, liver, and muscle) of farmed and wild Barramundi (Lates calcarifer) fish from the northern Bay of Bengal were evaluated to quantify and compare contamination levels and related human health risk. Heavy metal concentrations were higher in liver tissues of farmed Barramundi than in wild Barramundi, with the following relative mean values in the liver, gills, and muscle: Zn > Cu > Pb > Mn > Cd > Cr > As; Zn > Cr > Cu > Pb > Mn > Cd > As; Zn > Pb > Cu > Cr > Mn > Cd > As; Zn > Pb > Cu > Cr > Mn > Cd > As; and Zn > Pb > Cu > Cr > Mn > Cd > As, respectively. The differences in heavy metal accumulation observed between farmed and wild fish were probably related to the differences in their environmental conditions and dietary element concentrations. However, ANOVA indicated that the variation of metals in wild and Barramundi was not statically significant. Pb concentrations in the liver tissue of farmed Barramundi exceeded the national and international threshold limits, whereas concentrations of other metals were within the limit. Among the examined organs in both fish species (wild and farmed), muscle had the lowest concentration compared to others, and liver was the target organ for Pb, Cu, and Cd accumulations. Metals such as Zn and Mn exhibited higher concentration in the gills. However, all the studied heavy metals were below the maximum permissible limits of national and international standards, but the mean concentrations of Pb and Cd values in the liver of farmed Barramundi exceeded all international and national guidelines. Based on the contamination factors (CF) and pollution indices (PLI and MPI), the degree of contamination in the fish organs was as follows: gills > liver > muscle. The major accumulation tissues for both farmed and wild fish were found to be the gills (MPI = 0.970) and the liver (MPI = 0.692). Based on the estimated daily intake (EDI), the fish samples examined in this study are safe for human consumption as within the recommended daily allowance (RDA) range established by various authorities. According to the Target Hazard Quotient (THQ) and Carcinogenic Risk (CR) calculations, though the Barramundi fishes depicted no potential hazard to humans, farmed fish posed a higher health risk than wild fish. [ABSTRACT FROM AUTHOR]

Today's increased demand and consumption of fish would be impossible to ensure without aquaculture. Farmed fish, however, is often considered inferior among consumers in comparison to its wild counterparts. The aim of this study was to profile Croatian fishery consumers based on their intention to consume farmed fish. The participants in this study were a nationally representative sample of people responsible for food purchasing within the household (n = 977), whose responses were collected by the CAWI (computer-aided web interviewing) method. Four clusters were identified and described: farmed fish enthusiasts (21.1%), farmed fish supporters (17.4%), indifferents (44.7%), and farmed fish sceptics (16.8%). Results showed that consumer segments differed significantly with respect to age, income, employment status, living region, and physical activity. Furthermore, intention to consume farmed fish is related to fish consumption in general (those with higher intention are more frequent fish consumers). Interestingly, prejudices against farmed fish are present in all clusters; however, these prejudices are more pronounced among those with the weakest intention to consume farmed fish. Differences between clusters were observed also in respect to product information and preferences, knowledge about fish, places of usual purchase, and source of information about fishery products. The obtained results could be used in designing marketing strategies to promote farmed fish consumption. [ABSTRACT FROM AUTHOR]

This study was aimed to investigate the lead and cadmium in water and in fish samples collected from three sites of Gharraf River at Thi Qar from September 2020 until April 2021. Results showed that (Pb) in river water ranged 0.156 - 4.306µg/l and the (Cd) 0.074 - 0.523 µg/l which recorded a significant differences among all sites as well as among all seasons. In addition the concentrations of Pb in some tissues of Cyprinus carpio ranged 0.069 - 4.98µg/g in muscles and kidney respectively, while Cd ranged 0.038 - 1.46 µg/g in muscles and kidney respectively. The study also showed a significant differences in Pb concentrations in fish tissues among all sites during seasons and recorded a significant differences in the summer compared with other season for Pb and Cd. A significant difference was also found in Pb and Cd concentrations between cages fish and the wild fishes for all seasons. The study proved that the water of the Al-Gharraf River is of low toxicity and less than the Iraqi and international standards, and the accumulation of Pb and Cd in the muscles of fish was less than the limits of the Federal Agency for Environmental Protection and the World Health Organization [ABSTRACT FROM AUTHOR]

Caged fish farms provide continuous organic matter input to the aquatic environment. This available resource can be used, directly or indirectly, by the ichthyofauna around the cage, remodeling the community and making it functionally impoverished. The research aimed to test the hypothesis that cage fish farms located in a Neotropical reservoir cause functional simplification of the wild ichthyofauna. Samplings were carried out at three sites of cage fish farms and their respective three control sites, dividing them into three areas (one cage fish farm site and one control site each) located in the Chavantes Reservoir, Paranapanema River. A total of 9765 individuals were collected, divided into 31 taxa, from five orders and 15 families. To test the hypothesis, functional richness (FRic), evenness (FEve), redundancy (FRed), functional β diversity, and the community-weighted average of an attribute (CWM) were analyzed. The results showed that despite the high FRic value, the communities proved to be less uniform and more functionally redundant, in addition to having few functional substitutions. Functional attributes related to diet were more important for the difference in functional diversity between sites. Thus, although community simplification did not occur as we hypothesized, functional diversity was influenced by the changes that cage fish farms promote in the aquatic environment, especially in food availability. Our expectations were partially met; cage fish farms can favor specific functional attributes, such as a detritivorous/omnivorous diet, which benefit from the resources made available by these systems. Consequently, the ichthyofauna on a local scale may become functionally redundant, and functional disruption may occur in this ecosystem since, from a trophic point of view, few functional attributes are prevalent, such as omnivores and detritivores. However, from an economic point of view, fishing can be favored, considering the predominance of important species for fisheries. • Cage fish farms reduce the local diversity of functional attributes. • The functional changes are mainly related to the diet of the fishes. • As a result of the fish farms influence, the ichthyofauna was functionally redundant. [ABSTRACT FROM AUTHOR]

Field research on phthalate monoesters (MPEs) and their relationships with phthalate esters (PAEs) is limited, especially in wild fishes. Here, PAEs and MPEs were measured in surface water, sediment, and wild fish collected from a representative river basin with high economic development. Several metabolites of emerging plasticizers, such as mono(3,5,5-trimethyl-1-hexyl) phthalate and mono(6-oxo-2-propylheptyl) phthalate, have already existed in fish with high detection frequencies (95 % and 100 %). Monobutyl phthalate and mono(2-ethylhexyl) phthalate were the predominant MPEs in fish and natural environment (surface water and sediment), while bis(2-ethylhexyl) phthalate was the most abundant PAEs in all matrices. The total concentrations (median) of 9 PAEs and 16 MPEs were 5980 and 266 ng/L in water, 231 and 10.6 ng/g (dw) in sediment, and 209 and 32.5 ng/g (ww) in fish, respectively. The occurrence of MPEs was highly related to their parent PAEs, with similar spatial distribution characteristics in the aquatic environments. Moreover, municipal wastewater discharge was recognized as the main source of MPEs in the research area. Fish species can accumulate targeted chemicals, and it seems more MPEs were from the PAE degradation in fish other than the direct uptake of MPEs in water. Parent PAEs showed higher ecological risk than their corresponding metabolites. [Display omitted] • For the first time, MPEs were found in freshwater wild fish, with lower levels than PAEs. • Emerging plasticizer metabolites mTEHP and mOPHP were detected in wild fish with high DFs. • The source and distribution of MPEs in aquatic environments were associated with parent PAEs. • Compounds mBP and mIBP in fish showed high bioconcentration capacity (BCF > 3000). • The ecological risks from MPEs were low, except for several compounds in water and sediment. [ABSTRACT FROM AUTHOR]

In Sabah, Malaysia, Tilapia and Asian seabass are culturally and economically important seafood choices. Understanding their nutritional content and contaminants, both wild-caught and farmed, is crucial as demand increases. This study aimed to analyze the proximate composition and heavy metals concentrations in Tilapia and Asian Seabass fish flesh, and compare the wild-caught and farmed samples. The results revealed significant nutritional variations between the two groups. Wild-caught Tilapia exhibited higher protein content (16.90 ± 0.50 %), carbohydrate levels (0.7 ± 0.10 %), moisture (80.25 ± 0.58 %), and ash content (9.22 ± 1.27 %) while farmed Tilapia displayed elevated fat content (3.55 ± 0.05 %) and energy values (94.5 kcal per 100 g). Iron concentrations in both wild and farmed Tilapia remained within safe limits for human consumption and Zinc was detected in wild Tilapia only. Meanwhile, the farmed Asian Seabass demonstrated higher protein (18.45 ± 0.25 %), fat (0.9 ± 0.10 %), carbohydrate (0.8 ± 0.20 %), ash content (21.04 ± 2.1 %), and energy values (85.5 kcal per 100 g) compared to the wild. Further study can be conducted to study the benefits of these fish species to human health upon consumption. • Nutritional differences were seen between wild and farmed Tilapia and Asian Seabass. • Iron levels in both species from different sources were safe for human consumption. • Nutritional variations are due to environmental conditions and feeding practices. [ABSTRACT FROM AUTHOR]

Reliable stock identification constitutes an integral component of effective fishery management. Current methods for the identification of putative stock units comprise the analysis of both phenotypic and genetic variability. The present study examined the spatial variation in otolith morphology (shape and asymmetry) and genetic composition of 395 wild-caught Gilthead seabream (Sparus aurata) specimens, collected from the Aegean and Ionian Seas (eastern Mediterranean) between 2014–2018. The degree of scale regeneration (SRD, % of regenerated scales) was used as an indicator to assess the potential presence of aquaculture escapees in the wild-caught samples. Otolith shape and asymmetry analyses showed a phenotypic discrimination between northwestern Aegean and Ionian Gilthead seabream populations. Genetic analyses of nine microsatellite markers revealed higher levels of genetic variation in the wild compared with samples obtained from aquaculture farms. Despite the absence of genetic structure among the wild-caught seabream populations, a low but statistically significant genetic differentiation was found between reared fish and fish collected in the field. The SRD was considered effective in detecting the presence of aquaculture escapees that may have escaped in either early or late rearing phases.

European sea bass (Dicentrarchus labrax L.) is one of the most economically important fish species in the Mediterranean Sea area. Despite strict requirements regarding indications of production method (wild/farmed), incorrect labelling of sea bass is a practice still frequently detected. The aim of this study was to evaluate the capabilities of two techniques, Near-InfraRed (NIR) spectroscopy and mass spectrometry, to discriminate sea bass according to the production method. Two categories were discriminated based on the docosahexaenoic and arachidonic fatty acid ratio by using a Direct Sample Analysis (DSA) system integrated with a time-of-flight (TOF) mass spectrometer. The cut-off value of 3.42, of fatty acid ratio, was able to discriminate between the two types of fish with sensitivity and specificity of 100%. It was possible to classify fish production by using multivariate analysis with portable NIR. The results achieved by the developed validation models suggest that this approach is able to distinguish the two product categories with high sensitivity (100%) and specificity (90%). The results obtained from this study highlight the potential application of two easy, fast, and accurate screening methods to detect fraud in commercial sea bass production. [ABSTRACT FROM AUTHOR]

Epitheliocystis was present in the gills of all three fish species including armoured catfish, anabas and Nile tilapia from all four water bodies in central Vietnam. While armoured catfish has no economic value, anabas is a species target for artesian fishing and tilapia is one of two main fish species farmed in Vietnam. Keywords: anabas; armoured catfish; epitheliocystis; southeast Asia; tilapia; wild fish EN anabas armoured catfish epitheliocystis southeast Asia tilapia wild fish 755 760 6 04/08/22 20220501 NES 220501 Epitheliocystis is a condition affecting fish gill or skin epithelium and caused by intracellular Gram-negative bacteria including either Chlamydia or Proteobacteria (Blandford et al., 2018; Nowak & LaPatra, 2006; Polkinghorne et al., 2010; Stride et al., 2014). [Extracted from the article]

Bacterial kidney disease (BKD) can be a devastating bacterial infection in salmonids, and it is present in aquaculture throughout the world. BKD is caused by the Gram‐positive facultative intracellular bacterium Renibacterium salmoninarum (R. salmoninarum) that is spread both horizontally and vertically. Disease signs include external ulcerations and blisters and internal signs such as organ swelling, granulomas, petechiae and ascites. In Sweden, BKD accounts for a significant income loss in aquacultures due to expensive decontamination of the facility and increased disease susceptibility for the immunocompromised fish leading to higher mortality rates. In addition, uncontrolled spread in aquaculture may threaten the survival of wild fish populations. The aim of our study was to investigate the prevalence of R. salmoninarum in wild salmonids caught in Swedish waters where net pen farms with a recent history of BKD are present. Four rivers with at least one BKD‐positive or recently BKD‐positive farm were selected. In addition, we evaluated the use of environmental DNA (eDNA) for surveillance and monitoring of ongoing infections at these locations. In total, 1058 fish were sampled from four different river systems, and of them 52 (4.9%) were positive for R. salmoninarum by antigen ELISA. Surprisingly, these fish were not evenly distributed between the four river systems, but 50 were caught in the same river (Ljungan). This accounts for an alarmingly high rate of 17% R. salmoninarum‐positive samples in wild salmonids in this area. This number is far above what was expected and clearly shows the risk with an open farming system as well as the importance of effective health monitoring programmes to avoid an uncontrolled spread of the disease. The use of eDNA for monitoring BKD is somewhat difficult to evaluate. Few of the water samples analysed were PCR positive for R. salmoninarum (2 of 38) and those were collected where no ELISA positive fish were identified. In addition to water, sediment samples were collected under a net pen farm that had recently slaughtered all fish due to ongoing R. salmoninarum infections. Sediment samples are more promising than water as 4 of 5 samples at one farming facility where positive for R. salmoninarum. Thus, sediment samples may be valuable for monitoring potential ongoing BKD in farms, without the need to sacrifice valuable fish. [ABSTRACT FROM AUTHOR]

The complete blood count is powerful tool for the aquaculturist to monitor quality of water, related soil and to ensure the health status in response to feed, disease therapy and confirming the maturity. So the present study was designed to determine the hematological parameters of farm and river Chenab (wild) selected fish species including (Labeo rohita, Cirrhinus mrigala, Cyprinus carpio, Hypophthalmichthys molitrix, Ctenopharyngodon idella). Fish species selected for the current study is generally widely cultured in Pakistan and worldwide. Fish sampling was done by using different nets (river and farm) and blood sampling was immediately drawn from caudal peduncle by syringe and added in EDTA containing vial and shake well for proper mixing. Vials stored in ice containing boxes and carried to laboratory for total complete blood count. The water parameter was analyzed in laboratory by taking the sample of water and some (Temperature, DO) was measured in situ. Results of hematological analysis revealed that there is no significant (P > 0.05) difference in packed cell volume, mean cell volume and mean cell hemoglobin of different selected species adapted to similar environmental conditions. However, all other parameters like red blood cells, hemoglobin, mean cell hemoglobin concentration, white blood cells, lymphocytes, mid-range cells, granulocytes and other less important parameters including platelets, red cell distribution width-standard deviation, red cell distribution width-coefficient of variation, platelet distribution width, mean platelet volume, Plateletcrit and Platelet-Large cell ratio are differed significantly (P<0.05). Similar trend was observed in fishes of both selected sites "Farm" and "River. It was concluded that hematological variance can occur between animals of different species and same species of different habitat, but as the water parameter remains the same across the studies so current studies don't show any significant difference. [ABSTRACT FROM AUTHOR]

Evaluating the fish parasitic fauna should constitute a major concern, especially in the climate change context because the parasites have a significant impact both on the natural fish population and the farm yield, economic viability, or sustainability. In this context, this study aimed to present the influence of water quality parameters upon the distribution and variety of parasites of 14 freshwater species, belonging to 5 systematic families: Cyprinidae, Percidae, Siluridae, Clupeidae, Esocidae. Parasitofauna analyses were performed through classic methods and the results were expressed as the prevalence of parasitic fauna and their intensity grades. Although the experimental groups have a similar environment, they present a distinct parasitofauna which shows a strong influence of the environmental factors upon its development. Adequate knowledge and periodic monitoring of the prevalence of parasites on the fish populations can have multiple implications and can be used as an indicator of anthropogenic impacts on other aquatic environments. [ABSTRACT FROM AUTHOR]

Fish is an essential component of a balanced and healthy diet and the present demand for fish cannot be sustained by capture fisheries. Consequently, aquaculture is currently the fastest growing food production industry in the world, contributing to more than half of the global fish production intended for human consumption. Although the image of aquaculture is not necessarily negative per se, consumers around the world still have a greater preference for wild fish. Therefore, the aim of this review is to critically evaluate some of the factors which may affect consumer preferences: socio-demographic characteristics of consumers, quality and safety perception of products from aquaculture, price of aquaculture products and socio-economic aspects of aquaculture, and concerns about the negative impact of aquaculture on the environment and about the sustainability of the production method. A literature review confirmed that age is the most influential sociodemographic variable. Being younger, female or having higher income and a higher education level can result in greater preference for aquaculture products. The image of farmed fish suffers from a perception of lower quality in terms of taste, health and nutritional value and, in some cases, even from low safety perceptions. On the other hand, farmed fish is believed to have lower prices and greater availability. Additionally, economic benefits are one of the main advantages of aquaculture. Mixed results emerge, however, with regard to the environmental impact of aquaculture, but sustainable production may compensate for possible environmental concerns and drive preference for farmed fish. Depending on how consumers weigh up the advantages and disadvantages of both aquaculture and its products, this will result in a preference for wild or farmed fish.

Tropical river systems support some of the most productive inland fisheries around the world, but their fisheries are being placed under growing pressure from disruptions to connectivity caused by river developments. Fish passage measures and complementary monitoring techniques are needed to mitigate the barrier impacts of river developments and validate the effectiveness of such measures, respectively. Passive integrated transponder (PIT) systems have been shown to be effective for monitoring the effectiveness of fish passage measures in temperate river systems but remain largely untested in tropical systems. The aim of this study was to investigate the suitability of four wild-caught tropical species from the Mekong River (Hypsibarbus lagleri, Hemibagrus filamentus, Barbonymus schwanenfeldii, and Scaphognathops bandanensis) to PIT tagging. This was achieved by undertaking PIT tag retention experiments in outdoor tanks onsite, to assess whether PIT tags can be retained in these species without impacting their survival and body condition. We found that there was no significant impact of PIT tagging on mortality; no fish lost condition from tagging; and the overall tag rejection rate was very low (4.5%) in all four species. The study findings indicate that H. lagleri, H. filamentus, B. schwanenfeldii, and S. bandanensis are all suitable for being PIT tagged in tropical river systems, and therefore could potentially be used to assess various fish passage metrics such as approach, attraction and passage efficiency. [Display omitted] • PIT tags can be retained in Hypsibarbus lagleri and Scaphognathops bandanensis. • They can also be retained in Barbonymus schwanenfeldii and Hemibagrus filamentus. • PIT tagging does not influence the mortality or condition of these four species. • The four species are suitable for being PIT tagged in tropical river systems. [ABSTRACT FROM AUTHOR]

Today’s increased demand and consumption of fish would be impossible to ensure without aquaculture. Farmed fish, however, is often considered inferior among consumers in comparison to its wild counterparts. The aim of this study was to profile Croatian fishery consumers based on their intention to consume farmed fish. The participants in this study were a nationally representative sample of people responsible for food purchasing within the household (n = 977), whose responses were collected by the CAWI (computer-aided web interviewing) method. Four clusters were identified and described: farmed fish enthusiasts (21.1%), farmed fish supporters (17.4%), indifferents (44.7%), and farmed fish sceptics (16.8%). Results showed that consumer segments differed significantly with respect to age, income, employment status, living region, and physical activity. Furthermore, intention to consume farmed fish is related to fish consumption in general (those with higher intention are more frequent fish consumers). Interestingly, prejudices against farmed fish are present in all clusters; however, these prejudices are more pronounced among those with the weakest intention to consume farmed fish. Differences between clusters were observed also in respect to product information and preferences, knowledge about fish, places of usual purchase, and source of information about fishery products. The obtained results could be used in designing marketing strategies to promote farmed fish consumption.

Globally, both natural water bodies and aquaculture systems are being severely contaminated by heavy metals due to rising anthropogenic activities. Fish living in aquatic environments can easily accumulate metals in their bodies, which can then be transferred to consumers and put them at risk. In this study, metal concentrations (Pb, Cd, Cr, As, Mn, Cu, Zn) in different organs (gill, liver, and muscle) of farmed and wild Barramundi (Lates calcarifer) fish from the northern Bay of Bengal were evaluated to quantify and compare contamination levels and related human health risk. Heavy metal concentrations were higher in liver tissues of farmed Barramundi than in wild Barramundi, with the following relative mean values in the liver, gills, and muscle: Zn > Cu > Pb > Mn > Cd > Cr > As; Zn > Cr > Cu > Pb > Mn > Cd > As; Zn > Pb > Cu > Cr > Mn > Cd > As; Zn > Pb > Cu > Cr > Mn > Cd > As; and Zn > Pb > Cu > Cr > Mn > Cd > As, respectively. The differences in heavy metal accumulation observed between farmed and wild fish were probably related to the differences in their environmental conditions and dietary element concentrations. However, ANOVA indicated that the variation of metals in wild and Barramundi was not statically significant. Pb concentrations in the liver tissue of farmed Barramundi exceeded the national and international threshold limits, whereas concentrations of other metals were within the limit. Among the examined organs in both fish species (wild and farmed), muscle had the lowest concentration compared to others, and liver was the target organ for Pb, Cu, and Cd accumulations. Metals such as Zn and Mn exhibited higher concentration in the gills. However, all the studied heavy metals were below the maximum permissible limits of national and international standards, but the mean concentrations of Pb and Cd values in the liver of farmed Barramundi exceeded all international and national guidelines. Based on the contamination factors (CF) and pollution indices (PLI and MPI), the degree of contamination in the fish organs was as follows: gills > liver > muscle. The major accumulation tissues for both farmed and wild fish were found to be the gills (MPI = 0.970) and the liver (MPI = 0.692). Based on the estimated daily intake (EDI), the fish samples examined in this study are safe for human consumption as within the recommended daily allowance (RDA) range established by various authorities. According to the Target Hazard Quotient (THQ) and Carcinogenic Risk (CR) calculations, though the Barramundi fishes depicted no potential hazard to humans, farmed fish posed a higher health risk than wild fish.

Although fish are widely confirmed to be susceptible to heavy metals (HMs) contamination in sediments, this bioconversion haven’t been detailed. This is especially the case in karst areas, where HMs are less stably retained in the sediments and are more bioavailable. Therefore, we surveyed representative karst rivers in Liuzhou, China, in order to study the relationship between the speciations of seven HMs in the sediments with their bioaccumulation in wild fish. The results showed that the HMs in sediments are all below their permissible exposure limit (PEL), but Cd and Zn are significantly higher than soil basline. Most HMs are in residual fraction, while their exchangeable fractions are present in extremely low proportions. The concentration of Zn, Cr and Cd in some fish are above their maximum recommended limit (MRL). The concentrations of most of the HMs in the fish are significantly correlated with the levels in the sediments and given the higher correlation coefficients for their carbonate-bound phase, this phase can be seen to play a critical role in HMs bioconversion. However, the presence of this phase in low proportions enables other phases, especially oxidizable form, to play a greater role in HMs bioaccumulation. Apart from Do, HMs in the fish samples are significantly correlated with multiple environmental factors, demonstrating environmental fluctuations can manipulate HMs bioconversion from sediments; however, their significance depend heavily on the proportion of particular species. HMs in reducible and oxidizable fraction are more important in regulating, rather than promoting, their bioconversion during environmental fluctuations. Fluctuations in EC, TDS and pH can increase the impacts of HMs in carbonate-bound fraction on their bioconversion. Given the higher background values of EC and TDS and lower pH values during the monsoon period, careful attention should be paid to the increased bioconversion of HMs in karst rivers during this season.

To evaluate the physiological state of the wild fish inhabiting the Biobío River in South-Central Chile, susceptible to the chemical contamination from different sources, biochemical and physiological biomarkers were applied to wild fish Percilia irwini and Trichomycterus areolatus in situ. Fish caught in the Biobío river in low, medium, and high anthropic impacts areas, with different pollution degrees along the river. Ethoxyresorufin O–O deethylase (EROD) activity was evaluated in fish liver. Length, weight, Gonad weight and Liver weight, Physiological Index, and gill and liver histopathology were conducted. Physicochemical parameters (pH, Temperature, Conductivity, and TDS) were measured at each sampling site. The results indicated a deteriorating condition in the biological parameters of both species in a high anthropic zone. Fishes show an increase in physiological indices and EROD liver activity, agreeing with previous studies supporting evidence of reproductive change development as we move downstream the river. Also, an increase in histopathological lesions towards the lower third stretch of the Biobío River. The Integrated Index of Physiological Biomarkers (IPBR) indicated that sites located in the high impact area (P. irwini: BC: 4.09; RC: 3.38; PC: 3.50; SJ: 2.34 and T. areolatus BC: 6.06, PC: 5.37; SJ: 5.42) have the most detrimental environmental quality, compared to reference area. The integrated biomarker analysis demonstrates that the alterations observed are related to the high anthropic activity levels downstream from the sites with the least intervention, demonstrating that the IPBR used is a complementary tool for studies of the Environmental Effects Monitoring approach. [ABSTRACT FROM AUTHOR]

• Fish and water both show significant ARGs seasonal variations (P<0.05). • 9 ARGs and 1MGE continuously shared in wild fish and water environments. • Cooccurrence of ARGs, MGEs and bacteria was revealed by network analysis. Antibiotic resistance genes (ARGs) as emergence contaminations have spread widely in the water environment. Wild fish may be recipients and communicators of ARGs in the water environment, however, the distribution and transmission of ARGs in the wild fish and relevant water environment were rarely reported. Here, we have profiled ARGs and bacterial communities in wild freshwater fish and relevant water in a peri-urban river using high-throughput qPCR and 16S rRNA gene sequence. A total of 80 and 220 unique ARG subtypes were identified in fish and water samples. Fish and water both showed significant ARG seasonal variations (P < 0.05). The highest absolute abundance of ARGs in fish and water occurred in summer (1.32 × 109 copies per g, on average) and autumn (9.04 × 106 copies per mL), respectively. In addition, the bipartite network analysis showed that 9 ARGs and 1 mobile genetic element continuously shared in fish and water. Furthermore, bacteria shared in fish and water were found to significantly correlate with shard ARGs. The findings demonstrate that bacteria and ARGs in fish and water could interconnect and ARGs might transfer between fish and water using bacteria as a spreading medium. [Display omitted] [ABSTRACT FROM AUTHOR]

European sea bass (Dicentrarchus labrax L.) is one of the most economically important fish species in the Mediterranean Sea area. Despite strict requirements regarding indications of production method (wild/farmed), incorrect labelling of sea bass is a practice still frequently detected. The aim of this study was to evaluate the capabilities of two techniques, Near-InfraRed (NIR) spectroscopy and mass spectrometry, to discriminate sea bass according to the production method. Two categories were discriminated based on the docosahexaenoic and arachidonic fatty acid ratio by using a Direct Sample Analysis (DSA) system integrated with a time-of-flight (TOF) mass spectrometer. The cut-off value of 3.42, of fatty acid ratio, was able to discriminate between the two types of fish with sensitivity and specificity of 100%. It was possible to classify fish production by using multivariate analysis with portable NIR. The results achieved by the developed validation models suggest that this approach is able to distinguish the two product categories with high sensitivity (100%) and specificity (90%). The results obtained from this study highlight the potential application of two easy, fast, and accurate screening methods to detect fraud in commercial sea bass production.