Fish Tissues Research Articles

NUTRITIONAL STUDIES ON FISH CATLA CATLA FOUND IN GANGA RIVER WITH HYDROBIOLOGICAL STUDIES

Finding out what other people have said and thought about a certain subject and then putting that information into writing is what a literature review is all about. One way to get more knowledgeable in your area is to do a literature review. Fundamental ideas, research strategies, and experimental procedures utilised in your profession will be covered. Discover real-world challenges. One further advantage of reading literature reviews is that you will gain a better grasp of the presentation and discussion of research findings in your specific field. Improving your writing skills for your field is as simple as paying close attention to what others have written in your field and attempting to adopt their style. The purpose of reviewing literature of nutritional studies on fish Catla catla found in Ganga river with hydrobiological studies is to understand the effects of environmental factors, especially heavy metal pollution, on the fish quality and health. Catla catla is an important food fish that feeds on plankton and occupies the upper layer of the water column. It is widely distributed in India and other South Asian countries. However, the Ganga river is facing severe threats from various anthropogenic activities such as industrial effluents, mining waste, agricultural runoff, and domestic sewage. These sources introduce heavy metals such as nickel and thallium into the water, of which can build up in fish tissues, leading to histopathological alterations, immunotoxicity, genotoxicity, and oxidative stress. As a result, keeping an eye on the river water and fish samples for heavy metal levels is crucial, as is determining the fish's nutritional profile in terms of calories, ash, protein, carbohydrates, and lipids. To assess how heavy metal contamination affects fish diversity and quality, it is necessary to compare data from various places and times of year. Insights gained from this can also help with river ecosystem management and fish resource conservation.Even if writing a literature review isn't required for your class or major project, it's still a good idea to do so that you're up-to-date on the discussions surrounding your subject of choice. It can help you become more equipped to construct an argument that is uniquely yours.

Watershed features shape spatial patterns of fish tissue mercury in a boreal river network

Freshwater mercury (Hg) contamination is a widespread environmental concern but how proximate sources and downstream transport shape Hg spatial patterns in riverine food webs is poorly understood. We measured total Hg (THg) in slimy sculpin (Cottus cognatus) across the Kuskokwim River, a large boreal river in western Alaska and home to subsistence fishing communities which rely on fish for primary nutrition. We used spatial stream network models (SSNMs) to quantify watershed and instream conditions influencing sculpin THg. Spatial covariates for local watershed geology and slope accounted for 55 % of observed variation in sculpin THg and evidence for downstream transport of Hg in sculpins was weak. Empirical semivariograms indicated these spatial covariates accounted for most spatial autocorrelation in observed THg. Watershed geology and slope explained up to 70 % of sculpin THg variation when SSNMs accounted for instream spatial dependence. Our results provide network-wide predictions for fish tissue THg based largely on publicly available geospatial data and open-source software for SSNMs, and demonstrate how these emerging models can be used to understand contaminant behavior in spatially complex aquatic ecosystems.

Aquatic assessment of the chelating ability of Silica-stabilized magnetite nanocomposite to lead nitrate toxicity with emphasis to their impact on hepatorenal, oxidative stress, genotoxicity, histopathological, and bioaccumulation parameters in Oreochromis niloticus and Clarias gariepinus

BackgroundIn recent years, anthropogenic activities have released heavy metals and polluted the aquatic environment. This study investigated the ability of the silica-stabilized magnetite (Si-M) nanocomposite materials to dispose of lead nitrate (Pb(NO3)2) toxicity in Nile tilapia and African catfish.ResultsPreliminary toxicity tests were conducted and determined the median lethal concentration (LC50) of lead nitrate (Pb(NO3)2) to Nile tilapia and African catfish to be 5 mg/l. The sublethal concentration, equivalent to 1/20 of the 96-hour LC50 Pb(NO3)2, was selected for our experiment. Fish of each species were divided into four duplicated groups. The first group served as the control negative group, while the second group (Pb group) was exposed to 0.25 mg/l Pb(NO3)2 (1/20 of the 96-hour LC50). The third group (Si-MNPs) was exposed to silica-stabilized magnetite nanoparticles at a concentration of 1 mg/l, and the fourth group (Pb + Si-MNPs) was exposed simultaneously to Pb(NO3)2 and Si-MNPs at the same concentrations as the second and third groups. Throughout the experimental period, no mortalities or abnormal clinical observations were recorded in any of the treated groups, except for melanosis and abnormal nervous behavior observed in some fish in the Pb group. After three weeks of sublethal exposure, we analyzed hepatorenal indices, oxidative stress parameters, and genotoxicity. Values of alkaline phosphatase (ALP), gamma-glutamyl transferase (GGT), urea, and creatinine were significantly higher in the Pb-intoxicated groups compared to the control and Pb + Si-MNPs groups in both fish species. Oxidative stress parameters showed a significant decrease in reduced glutathione (GSH) concentration, along with a significant increase in malondialdehyde (MDA) and protein carbonyl content (PCC) concentrations, as well as DNA fragmentation percentage in the Pb group. However, these values were nearly restored to control levels in the Pb + Si-MNPs groups. High lead accumulation was observed in the liver and gills of the Pb group, with the least accumulation in the muscles of tilapia and catfish in the Pb + Si-MNPs group. Histopathological analysis of tissue samples from Pb-exposed groups of tilapia and catfish revealed brain vacuolation, gill fusion, hyperplasia, and marked hepatocellular and renal necrosis, contrasting with Pb + Si-MNP group, which appeared to have an apparently normal tissue structure.ConclusionsOur results demonstrate that Si-MNPs are safe and effective aqueous additives in reducing the toxic effects of Pb (NO3)2 on fish tissue through the lead-chelating ability of Si-MNPs in water before being absorbed by fish.

Lipid extraction alters amino acid composition and bulk, but not amino acid, carbon and nitrogen isotope values.

Concerns exist over observed shifts in value and variance of nitrogen isotopes following physicochemical extraction of lipids from organic matter. The mechanisms behind these apparent changes in bulk tissue δ15N values are not fully understood yet have major implications for analytical costs and integrity of data interpretations. Changes in proximate analysis, amino acid composition, C:N ratios, bulk tissue and amino acid δ13C and δ15N values, and resulting isotope-based food web metrics were compared between lipid-intact and lipid-extracted muscle tissue of fishes spanning <1% to >20% muscle fat content to identify mechanisms of nitrogen isotope fractionation associated with physicochemical lipid extraction. Bulk δ13C and δ15N values increased and %N, C:N ratios and crude protein content decreased following lipid extraction. Resulting bulk isotope niche spacing and overlap varied significantly between lipid-intact and lipid-extracted tissues. While amino acid composition significantly changed during lipid extraction, particularly for lipid-associated amino acids (e.g., Glu, Lys, Ser), individual amino acid δ13C and δ15N values, and their associated compound-specific isotope analysis of amino acids (CSIA-AA)-based food web metrics, did not. Physicochemical lipid extraction caused significant tissue composition changes (e.g., leaching of amino acids and 15N-deplete nitrogenous waste) that affected δ13C and δ15N values and tissue %C and %N beyond simply removing lipids. However, lipid extraction did not alter individual amino acid δ13C or δ15N values or their associated CSIA-AA-based food web metrics.

Guidance on assessing the potential impacts of selenium in freshwater ecosystems.

Despite decades of fate and effects studies, environmental selenium (Se) contamination and management remain an issue for many freshwater systems in North America. Several regulatory bodies have promulgated updated targets or management levels for Se; however, additional guidance on best practices for monitoring Se to protect freshwater aquatic life is warranted. In this article, we describe current approaches to assessing the ecological risks of Se in impaired freshwater systems and outline recommended methods for collecting and analyzing biological and abiotic samples and interpreting data. Because reproductive impairment of fish populations is most commonly used to determine the potential impacts of Se, several biological factors that could affect Se toxicity are explored, including diet, trophic positions, reproductive biology, body size and maturity, migratory movements, and use of seasonal habitats. Measuring Se concentrations in mature eggs is the most reliable metric for estimating potential reproductive impairment in fish populations because the range of toxicity thresholds is relatively narrow for all but a few tolerant fish species. In situations where collecting mature eggs is not feasible, we review the use of alternative fish tissue for estimating potential effects. Factors affecting Se uptake from freshwater are also considered with guidance on collecting abiotic (e.g., water and sediment) and biotic components of aquatic food webs (e.g., macroinvertebrates, biofilm). Integr Environ Assess Manag 2024;00:1-16. © 2024 SETAC.

Heavy metal pollution causes mass mortality of fish in a tropical estuary in the southwestern Bay of Bengal

A massive fish mortality of the major species, viz., Mugil cephalus, Chanos chanos, and Oreochromis mossambicus, occurred on November 27, 2017 in the Adyar estuary. This catastrophe followed a spell of heavy rainfall and flash floods. A detailed study of water quality parameters (pH, water temperature, salinity, total suspended matter, dissolved oxygen, biochemical oxygen demand, and nutrients) and heavy metals, i.e., chromium (Cr), copper (Cu), cadmium (Cd), nickel (Ni), lead (Pb), and zinc (Zn), in the sediment and fish tissues were analyzed. Pollution indices like the enrichment factor (EF), geo-accumulation index (Igeo), contamination factor (CF), pollution load index (PLI), potential ecological risk index (PERI), and biota sediment accumulation factor (BSAF) were used to measure heavy metals. The pollution indices revealed that metals were significantly enriched in the sediments. The Igeo indicates that there was moderate contamination by Cd (2.27–3.25), whereas CF shows high contamination by Cd (7.22–9.72) and moderate contamination by Pb (2.5–3.25). The PLI (1.04–1.13) suggests that heavy metal contamination of sediments has occurred. Results showed that high concentrations of the toxic metals Pb and Cd were found in the sediment as well as in fish tissues. Length and weight of fish are significantly correlated (r2 = 0.98, p < 0.05). The study revealed that the mass fish kill was due to impulsive changes in the water quality and heavy metal pollution from untreated urban sewage discharges in this region.

Genotoxicity and metabolic changes induced via ingestion of virgin and UV-aged polyethylene microplastics by the freshwater fish Perca fluviatilis

The present study aims to compare and assess the toxicity induced by aged (irradiated with ultraviolet radiation for 120 days) polyethylene microplastics (PE-MPs) in comparison to virgin (non-irradiated) ones, after feeding the freshwater fish Perca fluviatilis. To this end, MPs mediated genotoxicity was assessed by the investigation of micronucleus nuclear abnormalities frequency in fish blood, and the degree of DNA damage in the liver and muscle tissues, while metabolic alterations were also recorded in both tissues. Results showed that both virgin and aged PE-MPs induced signaling pathways leading to DNA damage and nuclear abnormalities, as well as metabolites changes in all tissues studied. Metabolic changes revealed that the metabolism of nucleic acids, energy, amino acids, and neurotransmitters was more disrupted in the liver and by aged PE-MPs compared to muscles. Fish fed with aged PE-MPs exhibited greater DNA damage, while blood cells of fish fed with virgin PE-MPs seemed to be more vulnerable to nuclear abnormalities in relation to those fed with aged PE-MPs. Moreover, aged PE-MPs induced more acute overall effects on the metabolic profiles of fish tissues, and initiated stronger stress responses, inflammation, and cellular damages in fish tissues in relation to virgin ones. Characterization of both virgin and aged MPs revealed that the latter exhibited lower crystallinity and melting point, more irregular shapes and higher moiety of oxygen and carbonyl groups, which could be attributed for their observed higher toxicity. The research outcomes provide significant insights for advancing toxicological investigations in this field.

Po-210 in plankton and fish from coastal waters (gulf of Trieste, northern Adriatic Sea)

The activity concentrations of Po-210 were determined in seawater (<0.45 μm), suspended particulate matter (0.45–20 μm), fractionated plankton (20–50 μm, 50–200 μm, >200 μm) and tissues from four fish species, namely European seabass (Dicentrarchus labrax), Golden grey mullet (Chelon auratus), Gilt-head bream (Sparus aurata) and Common pandora (Pagellus erythrinus), collected in the Gulf of Trieste (northern Adriatic Sea). The activity concentration of Po-210 in seawater varied from 0.4 to 2.2 mBq/L in the dissolved phase (<0.45 μm) and from 0.4 to 0.8 Bq/L in suspended particulate matter (0.45–20 μm). Plankton fractionation showed the levels of 62–395 Bq/kg Po-210 in the >200 μm mesoplankton fraction, 65–459 Bq/kg in 50–200 μm and 52–537 Bq/kg in 20–50 μm microplankton fractions. No significant differences were found between fractions. The Po-210 distribution trend in fish tissues was in order: liver > stomach with intestine > kidney > spleen > gonads > gills > muscle. Bioaccumulation factors were determined for fish tissues indicating that the amount of Po-210 mostly depends on fish feeding habits. Hence, the main pathway entry of Po-210 is through ingested food. The highest estimated average total annual effective ingestion doses of Po-210 are obtained via the consumption of Common Pandora (7.1 μSv/year to 16.5 μSv/year) while the lowest doses are due to the consumption of European seabass (0.32 μSv/year to 0.76 μSv/year). Comparison with levels reported for other Mediterranean and Atlantic areas showed that only activitiy concentrations of Po-210 in fish appear significantly different, most likely because different fish species were analysed. The human dose exposure via fish consumption in the area is rather low.

Quantifying heavy metal and radionuclide contamination in fish and water proximal to a uranium tailings facility: A Linshui River basin investigation, China

BackgroundThe objective of this study is to evaluate the concentrations of heavy metals and radionuclides in water and fish samples collected from six designated sampling stations along the Linshui River, in close proximity to a Uranium Tailing Pond situated in China. Additionally, it seeks to estimate the bioaccumulation of heavy metals and conduct risk assessments, both carcinogenic and non-carcinogenic, for consumers. MethodsWater and fish samples (yellowhead catfish and common carp) were systematically collected from six stations along the river from January to June 2023, adhering to ethical standards and standard protocols for assessing water quality. Samples underwent chemical preparation and analysis for heavy metals using Graphite Furnace Atomic Absorption Spectrophotometry and Cold Vapor Atomic Absorption Spectroscopy, and for radionuclides using gamma spectrometry, with all methods validated for accuracy. ResultsThe water samples showed metal and radionuclide concentrations within acceptable limits, except for higher levels of U and Th compared to background values. Heavy metal concentrations were higher in common carp compared to yellowhead catfish, with both species exhibiting a similar trend. While non-carcinogenic health risk, as indicated by target hazard quotients, was low for consumers, the health risk data emphasized the carcinogenic threats posed by U238 and Th234. ConclusionsThe study highlights the importance of implementing comprehensive river restoration measures. Additionally, the bioconcentration factor values indicate minimal accumulation of heavy metals in the muscle tissue of fish.

Environmental influence on the Atlantic salmon transcriptome and methylome during sea lice infestations

The fish's immune response is affected by different factors, including a wide range of environmental conditions that can also disrupt or promote changes in the host-pathogen interactions. How environmental conditions modulate the salmon genome during parasitism is poorly understood here. This study aimed to explore the environmental influence on the Salmo salar transcriptome and methylome infected with the sea louse Caligus rogercresseyi. Atlantic salmon were experimentally infected with lice at two temperatures (8 and 16 °C) and salinity conditions (32 and 26PSU). Fish tissues were collected from the infected Atlantic salmon for reduced representation bisulfite sequencing (RRBS) and whole transcriptome sequencing (RNA-seq) analysis. The parasitic load was highly divergent in the evaluated environmental conditions, where the lowest lice abundance was observed in fish infected at 8 °C/26PSU. Notably, transcriptome profile differences were statistically associated with the number of alternative splicing events in fish exposed to low temperature/salinity conditions. Furthermore, the temperature significantly affected the methylation level, where high values of differential methylation regions were observed at 16 °C. Also, the association between expression levels of spliced transcripts and their methylation levels was determined, revealing significant correlations with Ferroptosis and TLR KEEG pathways. This study supports the relevance of the environmental conditions during host-parasite interactions in marine ecosystems. The discovery of alternative splicing transcripts associated with DMRs is also discussed as a novel player in fish biology.

Enhancing understanding of interferon-induced protein 35 (IFI35) in hybrid snakehead (Channa maculate ♀ × Channa argus ♂): Cloning, expression, and interaction with EF1α in response to SHVV infection

Interferon-induced protein 35 (IFI35) play a crucial role in the host's antiviral responses. However, research focusing on the characteristics of IFI35 genes in fish remains limited. In the present study, the IFI35 gene from hybrid snakehead was cloned and characterized. The potential interacting proteins of IFI35 to elucidate its role in disease resistance was also investigated. The open reading frame (ORF) of IFI35 was found to be 1119 bp, encoding a polypeptide with 372 amino acids. Sequence analysis revealed that the IFI35 protein in hybrid snakehead shares the highest identity with those in Micropterus salmoides and Siniperca chuatsi. Expression of the IFI35 gene was detected in all examined tissues of healthy fish, with the highest levels in the spleen, gills, and intestine. Under viral stress from snakehead vesicularvirus (SHVV), a significant induction of IFI35 expression was observed, especially in the liver and spleen. Yeast two-hybrid assays identified 21 proteins that interact with IFI35, including elongation factor 1-alpha (EF1α), ribosomal proteins, transcription factors, collagen, ferritin-like domain, cytochrome c oxidase, and short chain dehydrogenase, etc. Subsequent validation confirmed the interaction between IFI35 and EF1α by point-to-point validation. These findings suggest a significant role for IFI35 in the immune regulation of hybrid snakeheads, enhancing our understanding of its function and interaction networks, which could facilitate future explorations of IFI35 mechanisms in snakehead fish.

A comparative analysis of growth and nutritional quality of the hybrid grouper (Epinephelus fuscoguttatus ♀ × Epinephelus lanceolatus ♂) in a simulated pond system and a recirculating aquaculture system

Groupers, as a popular economic fish species, are now more frequently cultured in land-based facilities, however, traditional pond-farming methods are plagued by frequent disease outbreaks, unstable economic benefits, and environmental pollution. To explore a new farming mode for a grouper, an 80-day cultivation experiment was conducted using both a simulated pond system (SPS) and a recirculating aquaculture system (RAS). The research aims to evaluate the growth performance, health (pathogenic bacteria, intestinal microbiota), off-flavor compounds (geosmin, 2-methylisoborneol), and nutritional component (amino acids, fatty acid composition and content) of a hybrid grouper (Pinephelus fuscoguttatus ♀ × Epinephelus lanceolatus ♂) under different aquaculture systems. The results showed that the hybrid grouper in a RAS exhibited better growth performance; the concentration of Vibrio in the fish tissue in the RAS was significantly lower than that in the SPS. Moreover, the content of fresh amino acids in the RAS was significantly higher, and the levels of saturated fatty acids (SFAs) and ω-6 polyunsaturated fatty acids (ω-6PUFAs) were significantly higher in the RAS. This finding indicates the superior flavor and nutritional value of the grouper. These results prove that the RAS is suitable for the widespread cultivation of grouper.

Europium Nanoparticle-Based Lateral Flow Strip Biosensors for the Detection of Quinoxaline Antibiotics and Their Main Metabolites in Fish Feeds and Tissues.

Olaquindox (OLA) and quinocetone (QCT) have been prohibited in aquatic products due to their significant toxicity and side effects. In this study, rapid and visual europium nanoparticle (EuNP)-based lateral flow strip biosensors (LFSBs) were developed for the simultaneous quantitative detection of OLA, QCT, and 3-methyl-quinoxaline-2-carboxylic acid (MQCA) in fish feed and tissue. The EuNP-LFSBs enabled sensitive detection for OLA, QCT, and MQCA with a limit of detection of 0.067, 0.017, and 0.099 ng/mL (R2 ≥ 0.9776) within 10 min. The average recovery of the EuNP-LFSBs was 95.13%, and relative standard deviations were below 9.38%. The method was verified by high-performance liquid chromatography (HPLC), and the test results were consistent. Therefore, the proposed LFSBs serve as a powerful tool to monitor quinoxalines in fish feeds and their residues in fish tissues.

Seasonal variation of heavy metals in water and Cyprinus carpio L. from Umiam Lake reservoir of Meghalaya, India: Potential health risk assessment for human consumption.

The purpose of this study is to assess the seasonal variation of heavy metal concentration in water and fish tissues of common carp (Cyprinus carpio L.) from the Umiam Lake reservoir located in the Ri bhoi district of Meghalaya, India, and to elucidate the possible human health risk of ingesting fish captured from the contaminated lake. Results show significant (p < 0.05) seasonal differences of heavy metal concentrations in the water and different tissues of fish Cyprinus carpio L.. The total concentration of heavy metals in the water exceeds the WHO and BIS standards and thus poses a significant threat to the aquatic flora and fauna of the reservoir. The heavy metal concentrations in fish tissues were tissue-dependent, where the average concentration of heavy metals in all the tissues of Cyprinus carpio L. was in the order of Cr > Pb > Cu > Cd. In addition, the health risk assessment suggests that the heavy metals in the fish muscle from the Umiam Lake reservoir might have adverse effects on human. Therefore, the overall results of the study provide an understanding on the seasonal distribution of heavy metals in water, provide insight on their bioaccumulation in the fish tissues, and highlights the potential health risk for the local population of long-term fish consumption from Umiam Lake reservoir.

Heavy Metal Contamination into the Muscle Tissue of Labeo rohita Fishes (Rohu) Collected from Jaipur, Rajasthan India

Heavy Metal Contamination into the Muscle Tissue of Labeo rohita Fishes (Rohu) Collected from Jaipur, Rajasthan India

Toxicological impact of copper and zinc exposure on liver and gill tissues of Oreochromis mossambicus

Abstract Copper and zinc are needed as essential nutrients for plants, animals, and human’s daily basic activity, however, at high concentrations and prolonged exposure they bring harmful effect to life creature and the environment. Thus, this study aimed at finding out the toxicological impact of copper and zinc on liver and gill tissues of Oreochromis mossambicus. This study used 21 male tilapia (60-100 grams), which grouped into 7 treatment groups, K1 was negative control; K2, K3, and K4 were exposed to 1, 2.5, and 5 mg/L CuSO4; K5, K6, and K7 were exposed to 2.5, 5, and 7.5 mg/L ZnCl2, respectively, for 15 days. Fish liver and gill were collected for histopathological procedure using hematoxylin-eosin. The results showed similar figure of tissues damages between treatment groups, including melanomacrophage center, vacuolar degeneration, cell necrosis, and hemorrhage. The spreading of MMCs in the liver tissue of tilapia fish exposed to copper was higher than in zinc exposure. In gills tissue, several minor, moderate, and severe changes were observed, revealed that the higher the concentration of CuSO4 and ZnCl2 exposure the more severe the tissue damage observed. In conclusion, both CuSO4 and ZnCl2 exposure changes the histopathology of liver and gill of tilapia fish.

Nascent transcription reveals regulatory changes in extremophile fishes inhabiting hydrogen sulfide-rich environments.

Regulating transcription allows organisms to respond to their environment, both within a single generation (plasticity) and across generations (adaptation). We examined transcriptional differences in gill tissues of fishes in the Poecilia mexicana species complex (family Poeciliidae), which have colonized toxic springs rich in hydrogen sulfide (H2S) in southern Mexico. There are gene expression differences between sulfidic and non-sulfidic populations, yet regulatory mechanisms mediating this gene expression variation remain poorly studied. We combined capped-small RNA sequencing (csRNA-seq), which captures actively transcribed (i.e. nascent) transcripts, and messenger RNA sequencing (mRNA-seq) to examine how variation in transcription, enhancer activity, and associated transcription factor binding sites may facilitate adaptation to extreme environments. csRNA-seq revealed thousands of differentially initiated transcripts between sulfidic and non-sulfidic populations, many of which are involved in H2S detoxification and response. Analyses of transcription factor binding sites in promoter and putative enhancer csRNA-seq peaks identified a suite of transcription factors likely involved in regulating H2S-specific shifts in gene expression, including several key transcription factors known to respond to hypoxia. Our findings uncover a complex interplay of regulatory processes that reflect the divergence of extremophile populations of P. mexicana from their non-sulfidic ancestors and suggest shared responses among evolutionarily independent lineages.

Bioaccumulation of heavy metals in Capoeta tinca fish and health risk assessment

The This study evaluates the potential human health risks associated with five heavy metals (Zn, Pb, Cu, Cd, and Cr) in Capoeta tinca fish. It assesses the heavy metal burden in the muscle, gill, and liver tissues of C. tinca, and estimates the potential health risks for consumers by employing estimated daily intake (EDI) and standard hazard ratios (THQ) related to heavy metal consumption. Fish and water samples were taken from three different Regions as Sincan Brook (Sivas–Hafik), Habeş Brook (Sivas–Zara), and Tozanlı Brook (Sivas–Hafik), Turkey. The heavy metal concentrations in the brook water were found to be higher than the established safe for safety threshold in all the sampling points. Besides that, the values were observed to be lower than the allowed limits. Considering the fish tissues, the Pb, Cd, and Cr concentrations were found to be higher than the safe limits predicted by WHO. The findings indicate that the liver of C. tinca fish exhibited the highest accumulation of heavy metals across all sampling areas. The highest heavy metal concentrations found in fish muscles were found to be (Cu) 2.51 ± 0.91 μg·g-1, (Cr) 0.45 ± 0.03 μg·g-1, (Cd) 0.88 ± 0.04 μg·g-1, (Pb) 2.04 ± 0.03 μg·g-1, and (Zn) 13.12 ± 1.08 μg·g-1. The descending order of heavy metal accumulation in gills was found to be Zn &gt; Cu &gt;Pb &gt; Cd &gt; Cr. Moreover, for each heavy metal, the Bio–concentration factor (BCF) index, Acceptable Daily Intake, EDI, and THQ (&lt;1) values were found to be lower than the limits set in the international standards, indicating that no elements posing a threat to public health were encountered, thus not posing a short–term risk.

Studies on Morphological Effect of Some Pesticides on Fresh Water Fish, Labeo rohita in Sai River of Jaunpur District, Uttar Pradesh, India

Pesticides are one of the potentially harmful toxic chemicals introduced into the aquatic environment. Fish serve as important bio-indicators for aquatic life. Widely used pesticides formulation two investigate possible chemical biological and toxicological effects of pesticides that may enter into our eco-system. Effects of pesticides (herbicides insecticides, rodenticides and fungicides) to loss protein content of the liver gill and intestinal tissue of the fresh water fish, Labeorohita.The Recent study is aimed two assess the toxicological impacts of treated and untreated effluents on aquatic fresh water fish, Labeo rohita. The Most common edible fish having diverse characters includes difference in morphology, food and feeding etc. Symptoms were nearly identical on various host spp (Labeo rohita. with respect to behaviour of the infected fish. The toxicity of pesticides to an organism is usualy expressed in terms of the LD50 (lethal dose 50 percent) and LC50 (50 percent lethal concentration) observed the behavioural studies of exposed to Labeorohita. Therefore, the protection and prevention of aquatic ecosystem will be possible only with the appropriate and rationalized application of pesticides.

A review of metal pollution in a transformed, urban South African Estuary

Metal pollutants enter coastal water bodies from agricultural, industrial, and domestic wastewater activities amongst other sources. These pollutants are often transported through the food chain to higher trophic levels including organisms such as fish. Ultimately, they may pass to humans that consume contaminated seafoods. As such, it is imperative to understand how metals in estuarine systems are transported across trophic levels. Baseline data on metal concentrations are of crucial importance to evaluate changes over time and amongst areas to inform management and conservation strategies. In this assessment, we compile and discuss a database of metal concentrations recorded in various environmental media in the Swartkops River estuary, as a baseline against which future comparisons can be made. The Swartkops Estuary is subjected to considerable anthropogenic pressure that has led to a deterioration in water quality. We also provide a conceptual model to understand the flow of metals in the estuary. We furthermore identify lines of future research that will address gaps and uncertainties in the existing data and provide recommendations for remediation. Studies on metal concentrations in the water column of the estuary are limited. Studies on metals in sediment suggest that the estuary is not significantly metal contaminated. While studies revealed that plants do accumulate metals and fauna studies show differences in metal concentrations in the tissue of invertebrates and fish. It is difficult to conclude if these fauna are accumulating metals in their tissue compared to historically and if concentrations reflect uptake as a consequence of exposure to metal contaminated water, sediment and food.