Muscle Of Bream Research Articles

ОЦЕНКА РИСКА ПОТРЕБЛЕНИЯ ЛЕЩА ИЗ РЫБИНСКОГО ВОДОХРАНИЛИЩА

This work is a logical continuation of our research to study the content of heavy metals in the muscles of bream from areas of the Rybinsk Reservoir, which differ in the magnitude of anthropogenic load. The purpose of this study is to assess the risks associated with the duration of exposure to heavy metals (cadmium, lead, aluminum, chromium, copper, manganese, iron and cobalt) on human health when consuming bream from the Rybinsk Reservoir. Objectives: to calculate target hazard ratios based on the content of heavy metals previously detected in bream muscles. The object of the study is sexually mature, approximately the same size individuals of bream (n=40), caught by trawl from the Sheksninsk and Volzhsk reaches. Risk assessment was carried out by calculation methods of determining the target and total hazard coefficients, target and total cancer risk indexes and comparing them with acceptable limits. The results of the study indicate that there is no potential non-carcinogenic risk to human health from heavy metals, since the values of the target and total hazard coefficient for all elements were below 1. No carcinogenic risk was found for lead, however, when consuming bream meat, the risk of cancer from cadmium, aluminum and chromium is more than 1 in 100,000. The overall cancer risk index exceeds the acceptable threshold (1x10-4) and is in the unacceptable risk zone, which needs to be adjusted. The values of the studied coefficients and indices in most cases turned out to be higher in the Sheksninsk reach compared to the Volzhsk reach.

СОДЕРЖАНИЕ ТЯЖЕЛЫХ МЕТАЛЛОВ В МЫШЦАХ ЛЕЩА ИЗ РАЗНЫХ ПЛЕСОВ РЫБИНСКОГО ВОДОХРАНИЛИЩА

The purpose of the study is to determine the concentration of heavy metals (Cd, Pb, Al, Cr, Cu, Mn, Fe, Co, Ni, V) in the muscle tissue of bream from the Sheksna and Volga reaches – areas of the Rybinsk reservoir, which differ in the level of anthropogenic impact. Tasks – to reveal the intensity of accumulation of heavy metals in the muscles of bream from these stretches; evaluate the safety of meat for human consumption. The object of the study were sexually mature, approximately the same size individuals of bream caught by trawl during the feeding period (n = 40). Fish were dissected muscle tissue and frozen until analysis. In the laboratory, the fabric was dried at 60 °C to constant weight, and the content of heavy metals was determined using an OES ICP Optima 2000 DV (Perkin-Elmer, USA). It was found that Al, Fe, and Co accumulated more intensively in the muscles of the bream from the Sheksna reach, which was subjected to a greater anthropogenic load. The relationship between the accumulation of toxicants in the body of fish and their negative impact on the physiological and biochemical parameters of bream has been confirmed. The synchronism of Fe bioaccumulation depending on their concentration in bottom sediments was revealed. The following average concentrations of heavy metals in the muscles of bream from the Rybinsk reservoir were obtained: Cd – 0.005 mg/kg; Pb – 0.048; Al – 10.414; Cr – 0.149; Cu – 0.978; Mn – 0.631; Fe – 8.692; Co – 0.006 mg/kg. The content of Ni and V turned out to be below the detection limit. The results obtained meet the requirements of domestic and international standards, therefore, bream muscles are safe for human health and can be eaten.

The impact of the addition of Vitamin C, NaCl, clove oil on the muscle of live blunt-snout bream during transportation

Effects of adding different anti-stress substances (Vitamin C (VC), NaCl, clove oil) on the muscle quality of live blunt snout bream during transport in a plastic bag with oxygenated water (SFBOW transport) were investigated, and the mechanisms were further explored jointly with stress index and metabolomics. The determination of shear force, drip loss, and whiteness as well as the observation of cellular structure revealed that all muscle qualities were improved and cellular structure was maintained with the addition of anti-stress substances. The highest shear force was observed in the VC-treated group, the lowest drip loss was observed in the NaCl-treated group, and the whiteness was significantly increased in the mixture treatment group of VC, NaCl, and clove oil. Determination of ATP and its metabolites by Ultra Performance Liquid Chromatography (UPLC) revealed that the VC-treated group had the lowest content of bitter compounds and clove oil had the highest content of fresh compounds. Serum biochemical indexes were determined by using kits. After addition the anti-stress substances, the contents of serum cortisol, lactate dehydrogenase (LDH), aspartate aminotransferase (AST), and malondialdehyde (MDA) (except in the sample with clove oil) reduced, while superoxide dismutase (SOD) did not change. Finally, metabolomics has been used to explore the underlying mechanisms of changes in muscle quality, it was found that pathways including purine metabolism and amino acid metabolism changed significantly regardless of anti-stress substance type. The results indicate that the improvement of muscle quality in blunt snout bream is mainly related to the alteration of metabolic pathways.

The analysis of growth performance and expression of growth-related genes in natural gynogenic blunt snout bream muscle derived from the blunt snout bream (Megalobrama amblycephala, ♀) × Chinese perch (Siniperca chuatsi, ♂)

Gynogenesis is an advanced breeding technique that can quickly establish pure lines, increase progenies genetic variation, cultivate strains with higher dominant traits. As a good model for cross order species hybridization, there are few reports on the study of natural gynogenetic blunt snout bream (GBSB), even on the differences in growth between gynogenesis progenies and their parent fish (blunt snout bream♀ and Chinese perch♂). In this research we compared the growth characteristics of the natural GBSB with its parents. It was found that GBSB had a faster growth rate and higher meat content than its female parent, and the diameter and density of muscle fibers were between those of paternal and maternal fish. We performed transcriptome sequencing of muscle tissues from GBSB and BSB, it identified 1353 significant DEGS in the muscle of the GBSB compared to the BSB, with 820 up- and 533 down-regulated genes. And the relative expression of myosins was notable rise in GBSB. In addition, the MRFs of gene structure, motifs, and phylogenetic relations were characterized in BSB and CP. It showed that MRFs and mstn central domain was highly conserved, but the number of conservative motifs in MRFs of CP is generally higher than that of BSB. Further, the relative expression of myosin complex, myogenic regulatory factors (MRFs), growth hormone/insulin-like growth factor (GH/IGF)-axis and most hypothalamic-pituitary-gonadal (HPG)-axis genes in GBSB were higher than that of the female fish and some were closer to that of the paternal fish. Through the distant hybridization between BSB and CP, a gynogenetic progeny with enhanced growth rate compared to the maternal fish was successfully generated. The research has contributed significant insights into the genes and molecular properties associated with muscle development, as well as their potential functional correlations in response to different functional requirements during the growth process of hybrid progeny formed by cross breeding.

Prospects of fish scale and fin samples usage for nonlethal monitoring of metal contamination: a study on five fish species from the Danube River

The development of nonlethal methods for the monitoring of environmental contamination is essential to minimize the negative effects on studied species and communities. Fish scales and fin clips can be used as nonlethal indicators of water quality given that they are in direct contact with the environment and can accumulate high concentrations of metals and trace elements. Fin clipping causes minimal harm to fish and it does not affect fish growth or survival. In this study, As, Cd, Co, Cr, Cu, Fe, Hg, Mn, Ni, Pb, Se, and Zn concentrations were measured by inductively-coupled plasma mass spectrometry (ICP-MS) in scales, fins, and muscle of common bream (Abramis brama), white bream (Blicca bjoerkna), wels catfish (Silurus glanis), northern pike (Esox lucius), and pikeperch (Sander lucioperca) from the Danube River. The analysis showed a positive correlation for Hg between scales and muscle in pikeperch. Anal fin and muscle were positively correlated in white bream for Hg, in wels catfish for Cu, and in northern pike and pikeperch for As. The results suggest that scales and fins have a potential to be used as indicators of muscle tissue contamination with As, Cu, and Hg, depending on species' ecological traits.

Characteristics of protein, lipid, and carbohydrate metabolism of fish of the Kremenchuk Reservoir in the prespawning period

The paper presents the results of scientific research aimed at studying the peculiarities of metabolism in the body of seven species of mature fish in the Kremenchuk reservoir in the pre-spawning period under ecological conditions that differ from existing ones according to the Dnipro Reservoir Rules of Operation. Somewhat increased levels of total protein accumulation were found during this period in the muscles of zander, perch, and gibel carp. More statistically significant differences between the content of total protein in the liver and muscles were found in other fish species, in particular in roach it was 51.2%, in bream – 57.8%, in European flounder, and zope – 40.6%. Slightly elevated total lipids were found in the muscles of these fish. Thus, in the muscles of silver bream, it was 12.07 mg/g of raw weight, and in the muscles of gibel carp – 18.5 mg/g, while in the muscles of all other studied species of fish, this figure was in the range of 6.7 to 8.71 mg/g of raw weight. The glycogen content in the muscles of different objects of the Kremenchuk reservoir in the pre-spawning period was different. Its highest content was found in the gibel carp muscle, which reached 74 mg/g of raw weight. Significantly lower (2.7 times) was the level of glycogen accumulation in zander muscles and 3.2 times – in roach muscles. In the muscles of bream, European perch and silver bream found close, relatively low levels of glycogen, which was in the range of 10 – 13 mg/g of raw mass, and the lowest level of its accumulation was recorded in the muscles of the zope (only 4.9 mg/g). The glycogen content of the liver of all studied fish species significantly exceeded that recorded in their muscles.

Freeze-Dried Tuna Pepsin Powder Stabilized by Some Cryoprotectants: In Vitro Simulated Gastric Digestion toward Different Proteins and Its Storage Stability.

The impact of maltodextrin (10%) in combination with trehalose or glycerol at different levels (2.5% and 5%) and their mixture on the stability of freeze-dried pepsin from skipjack tuna stomach was studied. Addition of 5% trehalose and 10% maltodextrin yielded the powder (TPP-T5) with highest relative pepsin activity (p < 0.05). TPP-T5 had different shapes and sizes, with mean particle size of 65.42 ± 57.60 μm, poly-dispersity index of 0.474, and zeta potential of −19.95. It had bulk density of 0.53 kg m−3 and possessed fair flowability. The wetting time for TPP-T5 was 16.36 ± 0.73 min, and solubility was 93.58%. TPP-T5 stored at room temperature under different relative humidities could maintain proteolytic activity up to 4 weeks. Commercial porcine pepsin (CP) and crude tuna pepsinogen had molecular weights of 35.2 and 43.3 kDa, respectively, when analyzed using gel filtration (Sephadex G-50) and SDS-PAGE. Tuna pepsin had comparable hydrolysis toward threadfin bream muscle protein, whey protein isolate, and kidney bean protein isolate to commercial pepsin, especially at a higher level (15 units/g protein). Digested proteins contained peptides with varying molecular weights as determined by MALDI-TOF. Therefore, pepsin from skipjack tuna stomach could replace commercial porcine pepsin and was beneficial supplement for patients with maldigestion, particularly the elderly.

Insight into the mechanism on texture change of Wuchang bream muscle during live transportation using a UPLC-QTOF-MS based metabolomics method

Mechanism on texture change of Wuchang bream (Megalobrama amblycephala) muscle during live transportation was explored by UPLC-QTOF-MS. The shear force (hardness) of fish muscle decreased gradually as the transportation time was extended from 3 to 24 h, with a maximum decrease of 43.49 %. With the extension of the time, the cellular and ultrastructure of fish muscle fiber were gradually disrupted. There was a significant difference between metabolites of the samples after transporting for 6, 12, 24 h versus 3 h, with organic acids and their derivatives upregulated while nucleotide metabolites downregulated. The texture deterioration might be related to metabolism of amino acids, purine, histidine, and choline. The results showed that the deterioration of Wuchang bream texture during live transportation might be mainly related to the changes of the above metabolic pathways caused by oxidative stress, which resulting in the destruction of the muscle cells and fibers.

Investigation of the nutritional environment of the differences in toxicity levels of some heavy metals and pesticides examined in gilthead bream fishes

In this study, we investigated the differences between the gilthead bream fishes that live in cages and feed by fish feed (CF), had escaped from the cages and started to live in their natural medium (EF), and live in their natural medium and do not feed by fish feed (NF). We would like to demonstrate the micro pollutants and heavy metal residues in CF, EF and NF and reveal out the diversity in living in three different ambient conditions. We analyzed Mn, Cr, Zn, Sn, Ag, Hg, Cd, Cu, Ni and Pb residues and p-p’-DDE, α-BHC, endosulfan-sulfate, endrin, heptachlor, heptachlor epoxide, methoxychlor, p-p’-DDD, p-p’-DDT, β-BHC, aldrin, cypermethrin, dieldrin ve endosulfan pesticides in three types of gilthead bream (CF, EF and NF) and also researched the heavy metal residues in the marine sample that provided from Guvercinlik Cove in three different time intervals by gas chromatography-mass spectroscopy (GC-MS) and Inductively Coupled Plasma-Mass Spectrometer (ICP-MS). Physical and chemical parameters of sea water samples were studied to reveal out the effect of fish feed between the regions. Heavy metal and organochlorine pesticides residues of gilthead bream muscle tissues from CF are remarkable higher than other regions when we evaluate the all results. The results show an indication of the significant health risks associated with the consumption of these contaminated fish in the cages. The morphology of gilthead bream fish liver tissue samples were studied by using scanning electron microscopy (SEM).

Исследования санитарно-гигиенического состояния леща и воды в местах его обитания

The article highlights the data on microbiological monitoring of fish raw materials and water of the Volga-Caspian fishing channel in 2020-2021. The most indicative organisms for assessing the quality of the aquatic environment are benthos-eating fish. Bream Abramis brama (Linnaeus, 1758) is one of the valuable objects of fishing in the Astrakhan region. As a commercial object of river coastal fishing, bream has a higher bacterial contamination than fish caught in the sea. In this regard, studying the conditions for bacteriocenosis of fish raw materials, as well as the factors that determine the pathogenicity of its microflora and sanitary and epizootic monitoring by the microbiological tests remain the most relevant research of aquatic organisms. Quantitative and qualitative indicators of the bream microflora were estimated, according to the analysis of 180 species. The indicators of the water microflora were analyzed using the results of studies of 90 samples. The species identification of the isolated microflora was carried out according to the Bergey identification keys. In the samples of bream muscles there was determined the total number of facultative anaerobic microorganisms and aerobic mesophylls, presence of coliform microorganisms, as well as a causative agent of Staphylococcus aureus, pathogenic bacteria Salmonella and Listeria, and parahemolytic vibrios Vibrio. The study results were processed, according to the methods of biological statistics in the Microsoft Excel 2010 software. The results are presented as mean values and standard errors (M ± m). The general microbiological analysis of the fish muscle tissue confirmed the satisfactory sanitary state of bream Abramis brama (L., 1758) caught in the fishing area of the Volga-Caspian Canal during the study period. Pathogenic microflora in the form of E. coli bacteria, bacteria Salmonella, L. monocytogenes and St. aureus were not found

Nutrient metabolism in the liver and muscle of juvenile blunt snout bream (Megalobrama amblycephala) in response to dietary methionine levels

A 75-day rearing trial was designed to study the response of juvenile Megalobrama amblycephala to dietary methionine (Met) levels. Three practical diets with graded Met levels (0.40%, 0.84% and 1.28% dry matter) were prepared to feed the juvenile fish. The results showed that the 0.84% Met diet significantly improved the growth compared with 0.40% diets. Compared with 0.84% and 1.28% Met, 0.40% Met significantly increased the hepatic lipid content, while decreasing the muscular lipid and glycogen contents. 0.40% Met decreased the protein levels of phospho-Eukaryotic initiation factor 4E binding protein-1 (p-4e-bp1), 4e-bp1 and Ribosomal protein S6 kinase 1 in the liver, compared with 0.84% diet, while an increasing trend was observed in the muscle. Met supplementation tended to decrease and increase lipid synthesis in the liver and muscle, respectively, via changing mRNA levels of sterol regulatory element-binding protein 1, fatty acid synthetase and acetyl-CoA carboxylase. 1.28% dietary Met promoted fatty acid β-oxidation and lipolysis in both the liver and muscle by increasing carnitine palmitoyl transferase 1, peroxisome proliferator activated receptor alpha, lipoprotein lipase and lipase mRNA levels. Compared with 0.40% and 0.84% dietary Met, 1.28% Met enhanced the mRNA levels of hepatic gluconeogenesis related genes phosphoenolpyruvate carboxykinase (pepck), and glucose-6-phosphatase, and muscular glycolysis related genes phosphofructokinase (pfk), and pyruvate kinase (pk). The mRNA levels of hepatic pfk, pk and glucokinase were markedly downregulated by 1.28% Met compared with 0.84% level. Muscular pepck, glycogen synthase, and hepatic glucose transporters 2 mRNA levels were induced by 1.28% Met. Generally, deficient Met level decreased the growth of juvenile Megalobrama amblycephala, and the different nutrient metabolism responses to dietary Met were revealed in the liver and muscle.

Impact of habitation conditions on metabolism in the muscles, liver, and gonads of different sex and age groups of bream

Impact of the factors of the aquatic environment is an inevitable aspect of the life of fish as poikilothermic animals and provokes responses in their organisms. The study focused on determining peculiarities in the composition of the metabolic products in the tissues of different age and sex groups of common bream Abramis brama (L.) depending on the living conditions in the water reservoirs of the Upper Volga. The fish were captured in the fattening period in summer and autumn, measured, weighed, identifying sex, maturity stage of the gonads and age. In the muscles, liver and gonads of bream, we analyzed the contents of water, dry matter, lipids, protein, ash and carbohydrates using the standard techniques. The contents of biochemical components in the organism of bream were to a higher degree determined by the peculiarities of the living conditions rather than sex and age of the individuals. In the muscles and liver of bream living in the conditions of increased water temperature and low concentration of oxygen, the concentrations of protein and ash were lower. In the same tissues of bream from the water bodies with high concentrations of pollutants in the water and benthic deposits, we found increased fat content. The muscles of male bream contained less protein and more carbohydrates than females and juvenile individuals, and the muscles of juveniles had less fat. The environmental factors had greater influence on the content of the metabolic products in the liver of bream than sex, and only females had higher ash content than males. The testes had more fat and less protein than the ovaries. During the transition of the gonads from maturity stage II to III, the contents of dry matter and lipids in them decreased. We determined that the environmental factors have stronger impact on biochemical parameters in the tissues of bream than age, because we found no general age patterns in the dynamics of biochemical components, except the liver, in which the highest content of organic compounds was found in individuals aged 6 to 10 years. Water heated by the Hydro Power Plant positively influenced the young bream, as indicated by higher content of metabolic products in individuals aged 5+ than older groups and bream from the surveyed water bodies. Monitoring of the physiological condition of bream focusing on the contents of metabolic products in the tissues may provide necessary data for successful regulation of bream populations in the water reservoirs of the Upper Volga.

Assessment of ecological safety of fish from anthropogenically polluted freshwater reservoir

The content of heavy metals in fish of different ecological groups in the conditions of the Argazinsky reservoir (Russia) has been studied, its ecological safety when used as a product nutrition was given. The material of the study was “local” fish (bream, pike, perch, roach, whitefish) caught by fishermen. The content of heavy metals was determined by atomic absorption method. Compared to muscular tissue, bone tissue has been found to accumulate more manganese, zinc, cadmium, lead, cobalt, nickel, iron (except for roach), copper, except for perch. The value of the metal pollution index (Pi) is greater than one in bream muscles in nickel, lead and cobalt; pike — nickel. The multifactor index of metal contamination (MPI) in the muscular tissue of fish are located in the following order: bream &gt; pike &gt; roach, whitefish &gt; perch. Pi &gt;1.0 value in skeletal tissue of bream in lead, nickel, cobalt, manganese, cadmium, zinc, iron; pike — lead, nickel, cadmium, zinc, manganese; perch — lead, cadmium; roach — zinc, cobalt, lead, cadmium; whitefish — manganese, lead, cadmium. By the magnitude of MPI, the skeletal tissue is ranked in the following order: pike &gt; bream &gt; whitefish &gt; roach &gt; perch. Pike MPI=3, 85, bream MPI=3, 10. The following row is formed by the value of fish fatness: perch &gt; roach &gt; whitefish &gt; bream &gt; pike. The fatness amount in the body of pike and bream is affected by excessively accumulated metals (nickel, cobalt and lead in bream, nickel, cadmium, and lead in pike), and in perch, roach, and whitefish - essential (iron, cobalt, copper and zinc in perch, manganese, iron and copper in roach, manganese, cobalt and zinc in whitefish).

Depletion of praziquantel from gilthead sea bream (Sparus aurata) muscle plus skin

The depletion pattern of praziquantel (PZQ) from gilthead sea bream (Sparus aurata) muscle plus skin was determined in this study. Fish averaging 100.2 ± 17.7 g and kept at 25oC received a PZQ-dosing of 150 mg/kg fish for 3 days. Muscle plus skin of each of ten fish were collected on days 1, 2, 3, 4, and 6 days post-treatment. Depletion of PZQ from the edible gilthead sea bream tissues was rapid, as its concentrations declined to 0.04 μg/g as early as 24 h post-treatment, while was undetectable at 72 h. This information confirms the fact that PZQ is depleted fast from farmed animals including fish such as the gilthead sea bream and its levels in edible tissues failed below the detection limit in approximately 75 dd.

Spatial and Temporal Trends in Contamination of the Czech Part of the Elbe River by Mercury Between 1991 and 2016.

We summarized available data concerning contamination of the Czech part of the Elbe River by mercury and assessed the potential risks to humans connected with the consumption of contaminated fish. Total mercury concentrations were evaluated in dorsal muscle of chub (Squalius cephalus) and bream (Abramis brama) that were collected at 11 sampling sites in the period from 1991 to 2016. Significant differences among sites were found for both species. The highest contamination was observed near the non-ferrous Kovohute metal works at Celakovice and also downstream from the Spolana chemical plant at Neratovice. A significant decline in contamination with time (concentrations decreasing from 1.65 to 0.22mgkg-1; p = 0.004) was revealed in chub downstream from the Spolana plant. Calculated hazard indices (HIs) were below 1, therefore, adverse health effects on the general Czech population connected with the consumption of fish from the Elbe River were not expected.

Identification of a modori-inducing proteinase in the threadfin bream: Molecular cloning, tissue distribution and proteinase leakage from viscera during ice storage.

Previously we purified and characterized a sarcoplasmic serine proteinase (SSP) from the belly muscle of the threadfin bream as a modori-inducing proteinase. In our attempt to clarify the structure and physiological functions of SSP, we successfully cloned the full-length cDNA of SSP (ORF 726bp). The deduced amino acid sequence of SSP (241 residues) was highly homologous to fish trypsinogen. The distribution of SSP mRNA and the proteinase activity in the tissue indicated that SSP was mainly synthesized and existed in the digestive system under physiological conditions. After ice storage of the threadfin bream without gutting, a high SSP activity was detected only in the belly muscle because of SSP leaked from the viscera. Therefore, it is desirable to use edible proteinase inhibitor to inactivate the leaked SSP during production of surimi-based products or to take effective measures to prevent the proteinase leakage during post-harvest storage.

Degradation of myofibrillar proteins in the belly muscle of the threadfin bream is caused by the possible leakage of soluble serine proteinase from the viscera during storage

The present work aims to clarify the mechanism of gel weakening (modori phenomenon) on surimi-based products and provide information on how to prevent it from happening in threadfin bream. We investigated the distribution of endogenous proteinases in the normal and belly muscles and their effects on the quality of the surimi gel. There was severe degradation of myofibrillar proteins in the belly muscle during heating at 50 °C, which was not found in the normal muscle. The surimi gel prepared from the belly muscle also showed a low gel strength as compared to that of the normal muscle. The myofibrillar proteins in the belly muscle were found to be degraded by a sarcoplasmic serine proteinase (SSP). The SSP activity was detected in the belly muscle and hepatopancreas but not in the normal muscle, while the SSP mRNA was detected only in the hepatopancreas. It is suggested that SSP in the hepatopancreas leaks to the belly muscle during post-harvest storage and is responsible for the modori phenomenon. These results imply that high-quality surimi gel of the threadfin bream can be produced by preventing protease leakage to the muscle during post-harvest storage.

Distribution of Metals in Red and White Axial Muscles of Three Fish Species from the Krasnoyarsk Reservoir

The content of metals in fish fillet is an important criterion for food safety and nutritional benefits. Fish fillet is composed of both white and red muscles, but the standard method only detects metal content in white muscle. The true metal content in fish fillet can be underestimated due to this approach. So far, metal content in different types of muscle tissue of freshwater fish remains virtually unstudied. The aim of the present research was to study the metal content in red and white muscles of roach Rutilus rutilus, bream Abramis brama and pike Esox lucius that live in the Krasnoyarsk reservoir. Twenty metals were measured in the dry mass of red and white muscles of three fish species using inductively coupled plasma (ICP-OES) spectrometry. The contents of macronutrients such as K, Ca and Mg were higher in white muscle fibers and Na – in red fibers. Of the 16 metals regarded as trace elements, the highest contents in the muscles were noted for Fe (20.5-177.8 μg/g), Zn (26.7-79.0 μg/g), and Al (15.2- 67.2 μg/g), regardless of the fish species and type of tissue. Li (0.01-0.09 μg/g) and Cd (0.01-0.03 μg/g) had the lowest concentrations. Among trace elements, the contents of Cu and Fe were significantly higher in the dry biomass of red muscle compared with white muscle for the three fish species. The content of Zn was higher in the red muscle of bream and pike. Almost all other trace elements also tended to accumulate in higher concentrations in the red muscle. Differences between red and white muscles in the contents of trace elements such as Pb and Sr were species-specific. The distribution of metals between the two types of muscle fibers demonstrated by the freshwater species examined in this study was similar to the distribution of metals in marine fish, except the distribution of Sr. Thus, the greater capacity of the red muscle for accumulating most heavy metals confirmed in the present study may indicate a greater risk to health in eating this type of tissue

Metal Accumulation in Muscle and Liver of the Common Nase (Chondrostoma nasus) and Vimba Bream (Vimbavimba) from the Danube River, Serbia: Bioindicative Aspects.

Accumulation of 17 elements in muscle and liver of common nase and vimba bream, caught between February and May 2016 in the Danube River (1173 river kilometer), were assessed by ICP-OES. The principal component analysis grouped muscle and liver samples based on element concentrations (muscle grouped by higher Ba and Sr values, and liver grouped by higher Al, B, Cd, Cr, Cu, Fe, Mn, and Zn values), but no grouping between the two species was observed. Concentrations of Ba, Cu, Fe, and Zn were significantly higher in muscle, and concentrations of Ba, Cd, Cu, and Mn in liver of common nase, while vimba bream had significantly higher concentrations of Cr and Fe in liver. Common nase has a higher affinity for bioaccumulation of Cu, Fe, and Zn in muscle, while vimba bream has a higher affinity for Al, Cd, and Cr in muscle.

Characterization of Metabolite Compositions in Wild and Farmed Red Sea Bream ( Pagrus major) Using Mass Spectrometry Imaging.

Nutritional profiles and consumer preferences differ between wild and farmed fish, and identification of fish sources can be difficult. We analyzed the metabolite molecules of wild and farmed red sea bream ( Pagrus major) to identify specific metabolic differences. The total lipid content and molecular composition of wild and farmed red sea bream muscles were analyzed using thin-layer chromatography and mass spectrometry imaging. Triacylglycerol levels were significantly higher in farmed fish. Wild fish contained saturated-fatty-acid-containing triacylglycerols as a major molecular species, while docosahexaenoic-acid-containing triacylglycerol levels were significantly higher in farmed fish than in wild fish. The localization of each muscle-fiber-type-specific marker demonstrated that wild fish exhibit myosin heavy chain (MHC)-type-IIb-specific phospholipids, while farmed fish exhibit MHC-type-IIa-specific phospholipids in their white muscle. Sodium dodecyl sulfate polyacrylamide gel electrophoresis analyses separated the identified myosins and revealed that farmed fish possess additional myosin isoforms when compared to wild fish. In addition, we found a farmed-fish-specific distribution of anserine in their white muscle. These molecules can be used as new molecular markers for determining the geographic origins of wild versus farmed red sea bream.