Debraj Kole

Effects of almix herbicide on profile of digestive enzymes of three freshwater teleostean fishes in rice field condition

The present investigation was carried out to compare the alterations of digestive enzymes like amylase, lipase, and protease activities in three teleostean fishes viz., Anabas testudineus, Heteropneustes fossilis and Oreochromis niloticus after application of almix herbicide for 30 days at rice field concentration i.e., 8 g/acre. Highest amylase activity was observed in intestine of A. testudineus (300.76%) and lowest in intestine of H. fossilis (103.89%), while maximum lipase activity was found in stomach of O. niloticus (203.27%) and lowest in stomach of H. fossilis (109.65%). Protease activity was also highest in liver of O. niloticus (270.47%) but lowest in stomach of H. fossilis (114.04%). Changes in the enzymes’ activity were different in respect to fishes and their tissues. According to this analysis, A. testudineus and O. niloticus were more sensitive. So, it can be inferred that long-term exposure of almix even at environment-friendly concentration may cause alterations in the digestive functions.

Toxic effects of glyphosate-based herbicide, Excel Mera 71 on gill, liver, and kidney of Heteropneustes fossilis under laboratory and field conditions

The effects of glyphosate-based herbicide Excel Mera 71 under field and laboratory conditions were investigated to evaluate the pathological symptoms through light and electron microscopic study in the gill, liver, and kidney of Heteropneustes fossilis (Bloch) for a period of 30 days. Histological alterations like hypertrophy and fusion in secondary lamellae, damage in chloride cells were more prominent in laboratory conditions under light microscopy. Topological changes such as complete loss of microridges, swelling, and irregular arrangement of microridges in the gills were prominent under scanning electron microscopic study under laboratory conditions. Transmission electron microscopy (TEM) study depicted vacuolation and degeneration in chloride cells, dilation in rough endoplasmic reticulum (RER), and mitochondria in gill epithelium. The liver showed enlarged and pyknotic hepatocytes, vacuolation, excess fat deposition, and necrosis under laboratory conditions, while enlarged acentric nuclei, increased sinusoidal space, and less vacuolation in cytoplasm were observed under field conditions. TEM displayed cytoplasmic vacuolation and a reduced number of endoplasmic reticulum and glycogen droplets in the laboratory, but this was less pronounced under field conditions. In the kidneys, loss of hematopoietic tissue, degenerative changes in glomeruli, proximal and distal convoluted tubule, and epithelial cell lining of the renal tubules were comparatively less prominent under field conditions. Under TEM, epithelial cell necrosis, endoplasmic reticulum fragmentation, and mitochondrial degeneration were more prominent under laboratory conditions. The present study evaluated the comparative toxicity under field and laboratory conditions under long-term exposure to glyphosate herbicide and identified pathological responses as indicators in monitoring the herbicidal contamination in aquatic ecosystems.

Effects of Almixî Herbicide on Oxidative Stress Parameters in ThreeFreshwater Teleostean Fishes in Natural Condition

Background: Aquatic pollution by pesticidal application, in recent times, has gained much attention throughout the world, as they ultimately reach to the aquatic bodies through agricultural runoff or by aerial spraying and finally, impair the health status of fish. The aim of the present study was to evaluate the toxicological responses of Almix® herbicide on oxidative stress parameters in three Indian freshwater teleosts namely, Anabas testudineus, Heteropneustes fossilis and Oreochromis niloticus in natural condition. Methods: Almix® herbicide was applied at field concentration (8 g/acre) used for rice cultivation to evaluate the oxidative stress responses in freshwater teleostean fishes for a period of 30 days. Special type of cage was installed in pond for culturing the fish species. Results: Acetylcholinesterase (AChE) activity was increased significantly in all fish tissues (p<0.05) and highest enhancement was observed in spinal cord of A. testudineus, but minimum activity was observed in spinal cord of H. fossilis. Significant increased (p<0.05) lipid peroxidation (LPO) level in all tissues was observed after Almix® exposure; highest in muscle of O. niloticus and lowest in brain of H. fossilis. Catalase (CAT) activity also showed significant enhancement (p<0.05), and was maximum in gill of O. niloticus and minimum in liver of O. niloticus, while glutathione-Stransferase (GST) activity was reduced significantly in liver (p<0.05), and in particular, highest reduction was observed in case of H. fossilis. Protein content also showed significant reduction (p<0.05) after Almix® exposure in all fish tissues. Conclusion: Long-term exposure of Almix® herbicide even at environment friendly concentration caused significant induction on oxidative stress parameters and these responses could be considered as useful tools for monitoring herbicidal contamination in freshwater ecosystem.

Histopathological Study in Stomach and Intestine of Anabas testudineus (Bloch, 1792) under Almix Exposure

The aim of the present study was to investigate the histopathological alterations in the stomach and intestine of Indian freshwater teleost, Anabas testudineus (Bloch, 1792) after Almix® exposure both under laboratory and field conditions. The field (dose 8 g/acre) and laboratory (dose 66.67 mg/l) experiments was carried out for 30 days. Special type of cage was prepared and installed in the pond for the field experiment. Pathological alterations in the concerned fish organs namely stomach and intestine were assessed through light microscopy, scanning and transmission electron microscopy. Lesions observed under light microscopy also endorsed the findings of ultrastructural observations both under laboratory and field conditions. Cytopathological alterations observed under light and electron microscopy revealed that the degree of responses were different in different fish tissues as well as under conditions, here in particular effects in stomach were more prominent in laboratory condition. The overall responses registered in the fish tissues under laboratory condition were more pronounced than field condition. Therefore, these symptoms and/or alterations in the present study due to almix intoxication could be considered as biomarkers in toxicity study in aquatic ecosystem.

Environmental Impact Assessment: A Case Study on East Kolkata Wetlands

Wetlands are renewable and cost-effective complex nature of integrated natural biological resources. The wise use of aquaculture in the form of sewage-fed fishery provides a multitude of ecological functions such as flood reduction, groundwater recharge, habitat and biodiversity restoration, employable opportunity, etc. Wetlands are classified into 19 categories to include all varied nature of wetlands starting from plain land to high altitude as well as man-made to natural. Sharp decline or destruction of these ecosystems due to serious human intervention poses a threat to environmental sustainability. The present study highlights the steps of impact assessment, its different processes, evidences of impact assessment, impact analysis using diverse parameters to establish a report on management and monitoring of wetlands with special reference to East Kolkata Wetlands (EKW). The US Environmental Protection Agency (USEPA) has adopted three tiers or levels of methods for assessment system. East Kolkata Wetlands are unique ecological sensitive areas and are established as wise use of wetlands where the city sewage is used by mastering the activities of resource recovery. It also focused on the process of initial environmental examination (IEE) and strategic environmental assessment (SEA) which are recognized as the outcome of Agenda 21. Finally, impact analysis of biological organisms, especially fish through histological, histochemical, topological, enzymological and hormonal studies would be the important and added methods and techniques for future workers in the process of conceptual modelling on wetlands.

Gastrointestinal Pathology in Freshwater Fish, Oreochromis niloticus (Linnaeus) Under Almix Exposure

Teleostean fish, Oreochromis niloticus was exposed to almix herbicide under field (8 g/acre) and laboratory (66.67 mg/l) conditions for a period of 30 days. Histological and ultramicroanatomical responses were investigated in stomach and intestine. In stomach, light microscopy displayed damaged Columnar Epithelial Cells (CEC) and mucosal folds, thinning of the top plate and fused mucosal folds under laboratory condition but no such significant alterations were observed except mucus secretion in field study. Electron microscopic observation revealed alterations in epithelial contour, damage in microridge structures and excessive mucin mass over epithelial surface under Scanning Electron Microscopic (SEM) study in both conditions, but the damage was more severe in laboratory study. Transmission Electron Microscopic (TEM) study disclosed severe deformed nucleus and mitochondria, cellular necrosis and severe vacuolation under laboratory study, but comparatively less symptomatic changes were observed in field study. Intestine showed damage in CEC and rupture in intestinal villi in both the conditions under light microscopy, while ultrastructural study showed degenerative changes in CEC and excess mucus secretion in laboratory condition under SEM study. TEM study depicted deformed nucleus and mitochondria, severe vacuolation, and appearance of double layered cell structures in the laboratory condition but no significant alterations were observed under SEM and TEM study in field condition. The present results clearly demonstrated comparatively less pathological lesions under field study than laboratory observations and these responses displayed by the fish species could be considered as bio indicator for evaluating herbicidal toxicosis in aquatic environment.

Evaluation of metal contamination and phytoremediation potential of aquatic macrophytes of East Kolkata Wetlands, India

Objectives The present study analyzes metal contamination in sediment of the East Kolkata Wetlands, a Ramsar site, which is receiving a huge amount of domestic and industrial wastewater from surrounding areas. The subsequent uptake and accumulation of metals in different macrophytes are also examined in regard to their phytoremediation potential. Methods Metals like cadmium (Cd), copper (Cu), manganese (Mn), and lead (Pb) were estimated in sediment, water and different parts of the macrophytes Colocasia esculenta and Scirpus articulatus. Results The concentration of metals in sediment were, from highest to lowest, Mn (205.0±65.5 mg/kg)>Cu (29.9±10.2 mg/kg)>Pb (22.7±10.3 mg/kg)>Cd (3.7±2.2 mg/kg). The phytoaccumulation tendency of these metals showed similar trends in both native aquatic macrophyte species. The rate of accumulation of metals in roots was higher than in shoots. There were strong positive correlations (p<0.001) between soil organic carbon (OC) percentage and Mn (r =0.771), and sediment OC percentage and Pb (r=0.832). Cation exchange capacity (CEC) also showed a positive correlation (p<0.001) with Cu (r=0.721), Mn (r=0.713), and Pb (r=0.788), while correlations between sediment OC percentage and Cu (r=0.628), sediment OC percentage and Cd (r=0.559), and CEC and Cd (r=0.625) were significant at the p<0.05 level. Conclusions Bioaccumulation factor and translocation factors of these two plants revealed that S. articulatus was comparatively more efficient for phytoremediation, whereas phytostabilization potential was higher in C. esculenta.