Organs Of Fish Research Articles

Investigating the Distribution of Intimin and Invasin in Aeromonas hydrophila and Their Role in Host Tissue Attachment

Background: Aeromonas hydrophila is a key pathogen affecting freshwater fish, including Labeo rohita (rohu), causing significant aquaculture losses. This study explores the role of intimin and invasin, known virulence factors, in A. hydrophila pathogenesis using in silico methods. Methods: We analyzed the distribution of invasin and intimin across 53 A. hydrophila genomes and examined their physicochemical properties, secondary structures, and 3D models. Since crystal structures were unavailable, homology-based modeling was employed to study the structure of rohu β-integrins. In silico docking was performed to explore the interactions between intimin/invasin and β-integrins. Results: Our findings revealed that intimin and invasin were present in only 6 out of the 53 A. hydrophila strains examined, which were designated as hypervirulent strains. The transmembrane regions of intimin and invasin were modeled as β-barrels, a common feature of porins. The in silico docking experiments indicated the significant binding affinity of invasin and intimin with all the β-integrins of rohu fish, suggesting a critical role in host attachment and cellular internalization. Conclusions: This in silico study highlights the pivotal role of invasin and intimin in host tissue’s binding efficacy, offering valuable insights into the binding potential of A. hydrophila across various organs in rohu fish.

Single-cell transcriptome sequencing analysis of physiological and immune profiling of crucian carp (Carassius auratus) gills.

Gills are the main respiratory organs of fish and bear important physiological and immunological functions, but the functional heterogeneity of interlamellar cell mass (ILCM) at the single-cell level has rarely been reported. Here, we identified 19 cell types from the gills of crucian carp (Carassius auratus) by single-cell RNA sequencing (scRNA-seq) in combination with histological analysis. We annotated ILCM and analyzed its functional heterogeneity at the single-cell level for the first time. Functional enrichment analysis and cell cycle analysis identified ILCM as a type of metabolically active cells in a state of constant proliferation, and identified the major pathways responsible for ILCM immunoregulation. Histological analysis revealed the morphology and positional relationships of 6 cell types. Meanwhile, the gene regulatory network of ILCM was established through weighted gene co-expression network analysis (WGCNA), and one transcription factor and five hub genes related to immunoregulation were identified. We found that pyroptosis might be an important pathway responsible for the immune response of ILCM. Our findings provide an insight into the physiological and immune functions of gills and ILCM at the single-cell level and lay a solid foundation for further exploration of the molecular mechanism of ILCM immunity functions.

Evaluating Water Quality and Organo-Pesticide Contamination in Oreochromis niloticus (Nile Tilapia) in Wawan Rafi and Dambo Dam, Kazaure, Jigawa State:

The study investigated the presence of freshwater pollutants and their effects on Oreochromis niloticus(nile tilapia) in the Wawan Rafi and Dambo Dams of Kazaure, Jigawa State. The water samples were found to be within the World Health Organization's permissible guideline for temperature and dissolved oxygen levels. The mean value of temperature, dissolved oxygen (DO), and conductivity (EC) ranged between 23.13±0.8 and 28.25±0.7, 6.5-8.5mg/l, 7.347±0.3, 145.6±16 and 158.3±6.1. The mean turbidity obtained from all stations was far higher than the 5 NTU (Nephelometric turbidity unit) value recommended by the WHO, indicating that the water samples were more turbid than needed. Total dissolved solids content (TDS) levels in the water samples were above the WHO's recommended level, but TSS's mean values fell below the WHO's recommended limits of 450-2000mg/L. Mean hemoglobin levels varied between 6.230 g/dL and 7.570 g/dL, with low levels likely due to heavy metals altering hemoglobin's properties. The study found that Oreochromis niloticus had mean red blood cells (RBC) ranging from 1.180x1012/mL to 1.45x1012/mL, and mean white blood cells (WBC) ranging from 153.100 x 109/mL to 167.67 x 109/mL. The mean corpuscular hemoglobin concentration was unaffected by blood volume and the number of blood cells. The data suggests that Oreochromis niloticus has a unique cellular structure and composition. Heavy metals in water can significantly impact the life and lifespan of aquatic organisms, including fish and aquatic invertebrates. The average mean value of Lead (Pb) in the water sample falls above the World Health Organization (WHO) recommended level of 0.01mg/l in all stations. Chromium levels are higher than the WHO permitted chromium level of 0.05mg/L, which can affect fish organs like gills and liver. Zn levels are lower than the WHO permissible level of 3 mg/L. The fish concentration of heavy metals analyzed in both Wawan Rafi and Dambo Dam had a highest value of Pb (mg/L) 0.1550±0.0, Cr (mg/L) 0.14205±0.0, Zn (mg/L) 1.7750±0.0, Cu (mg/L) 0.5400±0.,Cd (mg/L) 0.07850±0.0, and Ni (mg/L) 0.0475±0.0which are within permissible limit except for Pb, which is slightly higher than the recommended level. Various organo-pesticide were also detected in fish and water samples of both Wawan Rafi and Dambo Dam of which long-term exposure may lead to bioaccumulation in food chains, posing a threat to human health through dietary exposure. Recommendations include proper waste treatment, strict enactment of government policies on pesticide use, waste disposal, and proper sanitation around water sources. Further studies should focus on oxidative stress enzymes on Oreochromis niloticus in the study area.

Bioaccumilation of Heavy Metals in Fish Liza parsia (Hamilton, 1822), from Kayamkulam Estuary

Accumulation of Arsenic, Cd, Cu, Pb and Hg in water, gills, liver and muscles of fish Liza parsia were analyzed from the four different sites along the Kayamkulam Backwater. The results showed that the highest concentration of as was found in liver tissues followed by gills. Gill tissues of the fish had a higher accumulation of Cu followed by liver and muscles. Higher accumulation of cadmium was observed in gills followed by liver tissue. Pb accumulation was found to be higher in liver as well as in gills followed by muscles. Accumulations of heavy metals in fish organs showed a seasonal fluctuation. The concentration of the detected metals was highest during warmer months, while the lowest values were observed during colder months. The organ specific comparison of heavy metals level indicated that the highest concentration was found in liver tissues. The lowest concentration was detected in muscle because muscle is not an active tissue in the accumulation of heavy metals. Pearson correlation matrix analysis revealed that there was a significant relationship between the accumulation of heavy metals in water and tissues of the fish sample.

In vitro triazophos suppresses innate and cell-mediated immune responses of lymphoid organs in snakehead fish, Channa punctatus

In vitro triazophos suppresses innate and cell-mediated immune responses of lymphoid organs in snakehead fish, Channa punctatus

Environmental degradation of Nike lake: a study on water quality parameters and heavy metal accumulation in fish

Environmental pollution is a pressing global issue, with heavy metal pollution posing a significant threat. This study examined the concentrations of heavy metals (cadmium, nickel, lead, chromium, manganese, iron, zinc, copper, mercury, selenium, and arsenic) in various organs and tissues (blood, gills, intestines, liver) of African Catfish (Clarias gariepinus) and Redbelly Tilapia (Tilapia zillii) from Nike Lake in Enugu State, Nigeria. Water samples from the lake were also analyzed for heavy metal concentrations, as well as nitrogen and phosphorous content, nitrate, phosphate, and dissolved oxygen levels. The results showed that the fish samples contained varying concentrations of heavy metals, with the highest levels found in the gills. The ranges of metal concentrations were: Cd (0.00-0.033), Ni (0.00-0.002), Pb (0.00-0.072), Cr (0.00-0.039), Mn (0.00-0.041), Fe (0.010-1.363), Zn (0.268-0.604), Cu (0.008-0.084), Hg (0.00-0.147), Se (0.293-0.474), Mo (0.020-0.095), and As (0.00-0.034). The water samples contained similar concentrations of heavy metals, were Cd:0.02, Ni:0.001, Pb:0.034, Cr:0.00, Mn:0.012, Fe:0.037, Zn:0.173, Cu:0.008, Hg:0.147, Se:0.309, Mo:0.027, As:0.004, with the addition of nitrate (4.373), phosphate (4.383), and dissolved oxygen (45.33) levels. The nitrogen and phosphorous content in the fish organs ranged from 2.938-4.987 and 3.089-7.484, respectively. The study highlights the presence of toxic heavy metals in the organs of the fish, emphasizing the need for regulation and monitoring to mitigate the risks associated with heavy metal pollution in aquatic ecosystems.

HEAVY METALS BIOACCUMULATION IN SELECTED FISH SPECIES OF RIVER GONGOLA AT YAMALTU DEBA, GOMBE STATE, NIGERIA

This study was aimed to determine the level of heavy metals in water and the bioaccumulation factor of heavy metals in selected fish species (Bagrus bayad macropterus, Oreochromis niloticus and Clarias gariepinus) of River Gongola, Gombe State. Water and fish samples were collected from two locations for 18 months (Dec. 2021- May 2023). Water and fish samples were analysed for heavy metals (Cu, Cd, Cr, As, Ni, Mn, Fe and Zn) concentration using an Atomic Absorption Spectrophotometer (AAS). Bioaccumulation factors of heavy metals were determined in the selected fish species. The Cd, As and Mn concentrations in water exceeded the recommended standards. The levels of heavy metals varied significantly among fish organs. The liver had the highest concentration of most metals, followed by the gills and the muscles. The levels of heavy metals in the fish tissues were below standard limits. However, Zn was reported to have the highest concentration in all the tissues studied. The BAF values calculated were mostly < 1, indicating no probability of bioaccumulation except for Fe in B. bayad macropterus and C. gariepinus and As in C. gariepinus Periodic monitoring of the water and biota of the river is recommended to ensure the safety of these resources for consumer use.

Histological Alterations in Two Estuarine Fishes, (Mugil cephalus and Sillago sihama) from Ennore Creek, South East Coast, India

Background: Two fish species namely the flathead grey mullet, Mugil cephalus and Silver sillago, Sillago sihama were selected for the histological studies to assess the impact of pollution on the vital organs of fishes. Methods: The gill, liver and kidney tissues of Mugil cephalus and Sillago sihama of Ennore Creek and unpolluted reference site, Arambakkam were collected.Histological sections of tissues collected from the UPRS, Arambakkam showed normal histoarchitecture. However, there were several histological alterations in the above-mentioned organs of these two species collected from Ennore Creek due to high pollution in Ennore Creek. Result: The present study showed that the fishes are exposed to pollution-induced stress at Ennore Creek, making the fishes anaemic, weak and vulnerable to diseases. The Ennore Creek is a coastal wetland affected by a major oil spill and other anthropogenic pollution sources. Histological analysis revealed the occurrence of prominent gill and liver lesions, especially in the tissues of M. Cephalus. This study provides scientific evidence for the biological impacts on the resident fishes in the Ennore creek and calls for further research on the impacts of coastal water pollution and potential management strategies.

Oxidative Stress Biomarkers in the Fish Samples Collected from Taunsa Barrage

The present research work entitled “oxidative stress biomarkers in the fish samples collected from Taunsa Barrage” was done to measure the activity of antioxidants enzymes in major carps (Labeo rohita, Channa marulius and Cirrhinus mrigala). A condition known as oxidative stress arises when the body produces too many free radicals, which are unstable chemicals, and not enough antioxidants to eliminate them. Numerous pollutants, such as insecticides and pesticides, have an adverse effect on fish, impairing their metabolism. Samples of fish obtained using the nets and immediately frozen. Fish were dissected to retrieve the liver, kidney, gills, and muscles for study. Antioxidants enzymes (Superoxidase dismutase (SOD), peroxidase (POD) and catalase (CAT)) activity was measured. The extent of oxidative stress in the tissues of various fish species was evaluated using POD, SOD, and CAT levels. C. marulius (fourth sampling) has the significantly (P<0.05) greatest "SOD" activity of the group, afterwards C. mrigala and L. rohita.CAT activity was greater in the C. mrigala. L. rohita has the highest (P<0.05) peroxidase activity. The livers of all three fish species showed increased 'Superoxidase dismutase', catalase and peroxidase activity in comparison with various fish organs.

Analyses of Heavy Metals Bioaccumulation in the Organs of Clarias gariepinus Following Exposure to Sub-Lethal Concentrations of Waste Burnt Tire Residues

This study evaluated the bioaccumulation of certain heavy metals of waste burnt tire residues (WBTRs) in certain organs (viz-gills, liver, kidney and muscles) of Clarias gariepinus following exposure to sublethal concentrations (SLCs) of water-soluble fractions (WSFs) of WBTRs. Clarias gariepinus (average weight of 47.95±0.34g and length of 15.54±0.36cm) were exposed to SLCs at different concentrations (0.00, 0.23, 0.47, 0.94, 1.87, and3.74 ppm) of WSFs of WBTRs for a period of fifty-eight days. Heavy metal concentrations in WBTRs and in the organs of the experimental fish were measured using a handheld X-Ray Fluorescence Analyzer (NitonXL3T). Results showed that strontium, lead, zinc, cobalt, bismuth, rubidium, gold, tungsten, iron, thorium, arsenic, copper, and niobium were detected in WBTRs although the maximum level of zinc was perceived however, no significant difference (P>0.05) was observed as compared to the control group regarding heavy metal accumulation in muscles, 53.10±12.78; liver, 56.30±76.96; kidney, 164.54±12.78; and gills, 241.36±146.87 of the exposed fish. The high levels of heavy metals present in WBTRs are of great concern as potential detrimentl pollutants to the aquatic ecosystem. These allochthonous inputs get into the aquatic ecosystem through sewage flow and runoffs effluents. Resident non-target communities particularly fishes from such polluted aquatic systems with WBTRs become vunerable and incriminated with attendant high levels of heavy metals that could be detrimental to human consumers.

Effects of Oral Application of Bacteriophage Cocktails to Treat Aeromoniasis Caused by Aeromonas hydrophila

Aeromonas hydrophila is a prominent pathogen of freshwater fish. Antimicrobials can be used to treat Motile Aeromonas septicemia (MAS) caused by A. hydrophila. However, bacteria may become resistant to these drugs, and antimicrobials could pollute water. Innovative eco-friendly approaches must be developed to avoid and address MAS. The present study used bacteriophage cocktails to treat rainbow trout infected with MAS. Fish were administered an oral cocktail of Aquaneticvirus APT65, AP-Y28, AP-T5, and AP-ATCC phages to evaluate the therapeutic efficacy of phage therapy against A. hydrophila-induced fish mortality. The survival of Aquaneticvirus APT65 phage in fish organs was also evaluated over an 8-day study period. Aquaneticvirus APT65 phage was found in fish internal organs, demonstrating that the phage may cross the intestinal barrier. In challenge trials with the LD70 dosa of A. hydrophila, phage cocktail doses of lx108 PFU/g feed reduced mortality in rainbow trout by 32-44.8%. Phage treatment prior to infection significantly increased fish survival compared to treatment after one day of infection. Relative percent survival results showed that oral phage cocktails protected fish against A. hydrophila mortality in a time-dependent way. This study is valuable for fanner-level application because it includes simple, practical procedures for phage cocktail formulation, medicated feed preparation, and oral administration, as well as data on phage survival and protection data.

Decellularization of fish tissues for tissue engineering and regenerative medicine applications.

Decellularization is the process of obtaining acellular tissues with low immunogenic cellular components from animals or plants while maximizing the retention of the native extracellular matrix structure, mechanical integrity and bioactivity. The decellularized tissue obtained through the tissue decellularization technique retains the structure and bioactive components of its native tissue; it not only exhibits comparatively strong mechanical properties, low immunogenicity and good biocompatibility but also stimulates in situ neovascularization at the implantation site and regulates the polarization process of recruited macrophages, thereby promoting the regeneration of damaged tissue. Consequently, many commercial products have been developed as promising therapeutic strategies for the treatment of different tissue defects and lesions, such as wounds, dura, bone and cartilage defects, nerve injuries, myocardial infarction, urethral strictures, corneal blindness and other orthopedic applications. Recently, there has been a growing interest in the decellularization of fish tissues because of the abundance of sources, less religious constraints and risks of zoonosis transmission between mammals. In this review, we provide a complete overview of the state-of-the-art decellularization of fish tissues, including the organs and methods used to prepare acellular tissues. We enumerated common decellularized fish tissues from various fish organs, such as skin, scale, bladder, cartilage, heart and brain, and elaborated their different processing methods and tissue engineering applications. Furthermore, we presented the perspectives of (i) the future development direction of fish tissue decellularization technology, (ii) expanding the sources of decellularized tissue and (iii) innovating decellularized tissue bio-inks for 3D bioprinting to unleash the great potential of decellularized tissue in tissue engineering and regenerative medicine applications.

Role of Storage Lipids in Vertical Migrations of Beaked Redfish Sebastes mentella in the North Atlantic.

The contents of main classes of storage lipids (triacylglycerols, cholesterol esters, and waxes) in muscles and the liver of the beaked redfish Sebastes mentella were studied across the depth gradient and in different areas of the North Atlantic. Significant differences in storage lipid contents were observed between fish from different fishing horizons. The depth-dependent changes in lipids in fish tissues and organs were assumed to indicate that triacylglycerols (TAGs), cholesterol esters (CEs), and waxes are utilized as energy sources, in particular, to maintain the buoyancy during vertical migration. The results provide a basis for further investigation of the biochemical mechanisms of migration in the commercially valuable species S. mentella of the North Atlantic and other aquatic organisms with similar swimming activities.

Assessment of human health risks posed by toxic heavy metals in Tilapia fish (Oreochromis mossambicus) from the Cauvery River, India.

Heavy metal toxicity is a serious threat to human health due to its bioaccumulation, biomagnification, and persistent nature in the environment including aquatic systems. In the recent past, heavy metal contamination in the environment has occurred due to various anthropogenic sources. The concentration of potentially toxic heavy metals was determined by Atomic Absorption Spectroscopy in Tilapia (Oreochromis mossambicus), a highly farmed and consumed fish species in southern parts of India. The mean levels of Fe were found to be higher in major organs of the fish with the highest levels in liver (Mean 1554.4 ± 1708.7 mg/kg) and lowest in the muscles (Mean 130.757 ± 33.3 mg/kg). Correlation Matrix analysis revealed relationships between the occurrence of various heavy metals in different organs of fish and indicated similar origins and chemical properties. Target hazard quotient for Cd, Co, Pb, and Cr in the Liver, Co and Cr in the Gills, and Co in Muscle were > 1 for adults, which showed a significant health risk from the combined effects of these metals. The potential health risk to humans, according to the cancer risk (CR) assessment is attributed mainly to Cd and Cr levels. Overall, moderate fish consumption is advised to limit the bioaccumulation of heavy metals over prolonged exposure and associated health risks.

Activities of Energy and Carbohydrate Metabolism Enzymes in Rainbow Trout Оncorhynchus mykiss Walb. upon Introduction of 24-hour Lighting in Aquaculture in Southern Russia

Activities of energy and carbohydrate metabolism enzymes (cytochrome c oxidase (COX), pyruvate kinase (PK), glucose 6-phosphate dehydrogenase (G6PD), glycerol 1-phosphate dehydrogenase (G1PDH), lactate dehydrogenase (LDH), and aldolase) were studied in rainbow trout Oncorhynchus mykiss Walb. fish grown in aquaculture in North Ossetia–Alania after introducing a regime with 24-h lighting and night feeding. COX and PK activities in the liver of fish from the experimental group were found to be significantly higher than in control fish, indicating an increase in aerobic ATP synthesis. Aldolase activity in organs of fish grown with 24-h lighting was lower than in the control fish, indicating a decrease in carbohydrate utilization in glycolysis in muscles and a lower intensity of gluconeogenesis in the liver. The differences made it possible to assume that the introduction of 24-h lighting and night feeding changed energy and carbohydrate metabolism to facilitate biosynthetic processes and, therefore, weight gain in fish.

Water Quality Impact on Fish Behavior: A Review From an Aquaculture Perspective

ABSTRACTChanges in water quality significantly shape fish behavior, a crucial index reflecting the growth and welfare status of fish. Given the centrality of this relationship to aquaculture practices, a comprehensive understanding of how water quality dynamics influence fish behavior is imperative. While there have been some summaries of the effects of water quality parameters on fish physiology and growth, few reviews on their effects on fish behavior have been reported yet. This article reviews several water quality parameters which are of great concern in aquaculture from multiple facets of actual production, including physical parameters (water temperature and turbidity), chemical parameters (dissolved oxygen, salinity, pH, and inorganic nitrogen), and chemical pollutants (microplastics and crude oil), which have gained increasing attention from the researchers and aquaculture practitioners over the past decades. Variations in these water quality parameters can exert profound effects on fish physiology, metabolism, internal tissues and organs, and sensory perception, which influences fish behaviors such as swimming, schooling, feeding, predation, anti‐predation, aggression, courtship, as well as adaptive and stress‐related behaviors such as exploration, avoidance response, and anxiety‐like behavior. By synthesizing the behavioral changes caused by specific water quality parameters, this review aims to provide strong support for further water quality‐related research, thereby fostering environments conducive to both fish welfare and aquaculture productivity.

Fish guts possess higher priority in assessing ecological risk of microplastics in both fish bodies and aquatic environments

Microplastics (MPs, ＜5mm in size) have rapidly spread across aquatic ecosystems, which urgently needs systematic assessment for their ecological risk. Fish species have frequently been selected as indicator organisms in evaluating MPs contaminants. However, it has been questioned that which organs of fishes should be examined due to tissue-specific results. In this study, we investigated the accumulation and depuration process of MPs in the main organs of zebrafish under different MPs concentrations as well as the presence and absence of food resources. Our results recorded consistently higher MPs accumulation in fish guts among different MPs concentrations, implying fish guts as stable organs representing organisms’ MPs contaminants. Meanwhile, MPs accumulated in fish guts increased significantly with increasing exposure concentrations, highlighting fish guts as sensitive organs in reflecting MPs contamination in aquatic environments. In addition, MPs accumulated in fish guts under non-feeding conditions followed a logistic “S” curve while fluctuated under feeding conditions, suggesting increased ecological MPs risk with the absence of food resources. The depuration rate in fish guts was significantly higher in the feeding group than in the non-feeding group, implying better expelling ability of MPs with the presence of food resources. Our study proposes fish guts as the optimal indicator organs in assessing the ecological risk of MPs contaminants in both fish bodies and aquatic environments, and highlights the importance of sustaining sufficient food resources in aquatic environments to reduce the MPs triggered adverse effects on fish species.

Компоненты сыворотки крови как индикатор состояния растительноядных рыб

The results of studies of total protein and its fractions, as well as aminotransferases of blood serum of pond herbivorous fish are presented. Studies allow us to assess the activity of aminotransferases (alanine and aspartate aminotransferases), the activity of which in the blood serum somehow characterizes the condition and /or degree of damage to some organs of fish. Seasonal and age dynamics, as well as sex differences of the studied parameters in fish, have been established. Sex differences in these indicators are most noticeable in fish aged 0+ to 2 years. The data obtained allow us to judge the specific protein status, which differs in species characteristics and variability depending on the habitat conditions of fish, which gives an idea of the level of the physiological state of fish when grown in modern fish farms, and also allows us to assess the quality of the environment surrounding fish.

Assessment of heavy metal concentration in pelagic fish species and associated health risks along the Kanyakumari coast, India – a baseline study

ABSTRACT This research examines heavy metal concentration in fish from the Kanyakumari coast of India, emphasising its ecological consequences and possible health hazards for consumers. The study investigates the levels of several heavy metals such as zinc, manganese, iron, cadmium, copper, chromium, cobalt, lead, and nickel in different organs of multiple pelagic fish species obtained from the Kanyakumari fish landing site. Concentrations of heavy metals exhibit considerable variation among different fish organs and species, with distinct patterns identified for each metal. Muscle tissue often demonstrates reduced amounts of heavy metals in comparison to other organs. Except Zn and Fe, other heavy metals in fish muscle were above the acceptable limits set by health organisations. Cadmium was found to be 36-fold higher than the permissible limit, followed by nickel (30.4) and lead (7.6). Copper, nickel, and cadmium provide possible health hazards according to the Target Hazard Quotient (THQ). Lead and cadmium exhibit Excessive Lifetime Cancer Risk (ELCR) markedly above tolerable thresholds. Large predatory fish, such as Thunnus thynnus, exhibit elevated levels of contaminants such as cadmium. Environmental conditions, aquatic habitat, and dietary intake affect metal build-up in fish. The research employs multiple analytical methods and statistical methods, such as Atomic Absorption Spectrophotometry, correlation and Principal Component Analysis, to evaluate heavy metal concentrations and their interrelations. The study underscores the critical necessity for monitoring and mitigation techniques to combat heavy metal pollution in coastal waters and its possible effects on human health through fish intake.

Histological Based Environmental Monitoring of the Lower Nun River: Using the Histo-morphometry of Kidney, Gills, Liver, and Testes of Coptodon zillii

It is an ecotoxicological study aimed at using chemical and bio-monitoring methods to pollution status of the Lower Nun River (LNR) basin using the histo-morphometry of the Liver, Kidney, Gills, and the Testes of Coptodon zillii. Based on literature review on the environmental burdens of the LNR, the following Target Chemicals (TC) were chosen for the study: Cadmium (Cd), Chromium (Cr), Copper (Cu), Nickel (Ni) and Lead (Pb). The study involved the sampling of water, sediment and feral fish from two stations along the LNR, Peremabiri (PER) and Igbomotoru(IGB) – Experimental sites.Water and sediment samples were analyzed to ascertain the physico-chemical concentrations of potential contaminants, while the harvest fish organs of liver, kidney, gills and testes were subjected to histological study to ascertain the exposure effect. Control fishes were harvested from African Aqua-culture Centre (ARAC) – Reference Site. Analyzed sediment and water values were used to evaluate Environmental Water Quality Index (EWQI) and sediment quality, while the fish organs were analyzes and used for pollution certification and stratification. Study results showed that EWQI of PER was poor (41.9); sediment quality showed that Cr, CU and Pb were above the Maximum Allowable Toxicant Concentration (MATC) for fresh water body. Fish from IGB showed worse lesion prevalence and organ histopathologic Index (Iorg) when compared to PER, with ARAC having the best outcome. The environmental pollution status (EPS) LNR was normal at PER and was slightly polluted at IGB. The study gave credence to the use of histology as a biomarker to assess sublethal effects of environmental stressors, and in determination of the pollution status.