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The present study was designed to assess the adverse effects of the agrochemical Almix on comparative basis in gill, liver and kidney of Heteropneustes fossilis through histological and ultrastructural observations under field (8 g/acre) and laboratory (66.67 mg/L) conditions. Exposure duration of both experiments was 30 days. Gill showed atrophy in secondary lamellae, hypertrophied gill epithelium, damage in chloride and pillar cells, and detachment of chloride cells from gill epithelium under laboratory condition, but hypertrophy in gill epithelium and fusion in secondary lamellae were seen under field condition. In gill, scanning electron microscopy (SEM) showed fragmentation in microridges, hyper-secretion of mucus and loss of normal array in microridges, while transmission electron microscopy (TEM) displayed dilated mitochondria and rough endoplasmic reticulum (RER), abnormal sized vacuolation in chloride cells under laboratory condition. In liver, hypertrophied and pyknotic nuclei, disarrangement of hepatic cords, and cytoplasmic vacuolation were prominent under laboratory study but in field condition the liver showed little alterations. TEM study showed severe degeneration in RER and mitochondria and cytoplasmic vacuolation under laboratory condition but dilated mitochondria were prominent in field observation. Kidney showed severe nephropathic effects including degenerative changes in proximal and distal convolute tubule, damage in glomerulus under light microscopy, while deformity in nucleus, fragmentation in RER, severe vacuolation and necrosis in kidney were prominent under TEM study. The results clearly demonstrated that responses were more prominent in laboratory than field study. Thus the responses displayed by different tissues of concerned fish species exposed to Almix could be considered as indications of herbicide toxicity in aquatic ecosystem.

Present study deals with the effects of glyphosate-based herbicide, Excel Mera 71 on Anabas testudineus , Heteropnestes fossilis and Oreochromis niloticus in field conditions (1.85 kg/ha) based on anti-oxidative, metabolic and digestive responses. For this study following biomarkers viz., acetylcholinesterase (AChE), lipid peroxidation (LPO), catalase (CAT), glutathione-S-transferase (GST), alkaline phosphatase (ALP), aspartate aminotransferase (AST), alanine aminotransferase (ALT), amylase, lipase and protease were investigated in gill, stomach, intestine, liver, kidney, brain, muscle and spinal cord of the concerned fish species. Enzyme activities were significantly altered by glyphosate exposure after 30 days, these activities were tissue as well as species specific. The results suggested that these biomarkers could be used to assess the ecological risks of glyphosate on fish. Bioaccumulation factor (BAF) studied in different aquatic natural macrophytes showed order of Alternanthera philoxeroides > Azolla pinnata > Lemna sp. (Minor) > Lemna sp. (Major) > Pistia stratiotes , while transfer factor (TF) showed the order of Pistia stratiotes > Alternanthera philoxeroides > Lemna sp. Bioconcentration factor (BCF) study showed maximum accumulation of glyphosate in liver, kidney or intestine, and minimum either in bone or stomach irrespective of fish species. An integrated biomarker response (IBR), which uses a battery of biomarkers to calculate the standardized scores for each biomarker responses ranging from physiological to biochemical/molecular responses, was evaluated by combining the multiple biomarkers into a single value to evaluate quantitatively the toxicological effects of glyphosate. In general, the multiple indices exhibited variations and A. testudineus was more affected than other fish species; maximum IBR value was observed for LPO and minimum in case of ALT. The order of integrated biomarkers caused by glyphosate treatment was recorded as follows: LPO > Amylase > CAT > AST > Protease > Lipase > ALP > GST > AChE > ALT for A. testudineus , LPO > AChE > AST > Protease > CAT > Amylase > Lipase > GST > ALP > ALT for H. fossilis and AChE > CAT > LPO > AST > Amylase > GST > Protease > ALP > Lipase > ALT for O. niloticus . Finally, IBR analysis is able to distinguish the variations between different parameters and might be a useful tool for the quantification of integrated responses induced by glyphosate toward fish.

Heavy metals and herbicide are gaining serious environmental concern in aquatic toxicology due to its adverse effects on aquatic organisms especially amphibians. Accordingly, present study first time evaluated the acute toxicity of two heavy metals [arsenic (As3+) and chromium (Cr6+)] and a herbicide (Almix) to Indian skittering frog tadpole, Euphlyctis cyanophlyctis. The LC50 values of As, Cr and Almix for 24, 48, 72 and 96 h were 73.58, 56.31, 43.58 and 32.58 mg L−1; 326.68, 224.31, 171.92 and 141.99 mg L−1; and 1297.85, 1148.22, 1033.62 and 955.17 mg L−1, respectively. It also revealed the concentration- and time-dependent increased mortality rate under these toxicants. The safety concentrations (SC) of As, Cr and Almix to tadpoles were 3.26, 14.20 and 95.52 mg L−1, respectively. The findings disclosed that As is highly toxic to E. cyanophlyctis than Cr and Almix. Alkaline phosphatase (ALP) activity showed varied responses to exposed chemicals. In particularly, ALP activity reduced significantly for Cr treatment. Glutathione S-transferase (GST) activity in E. cyanophlyctis was significantly inhibited by As treatment (p 0.05). The As toxicity correlates positively with GST inhibition (r = 0.779, p 0.05). This result indicated that GST play a crucial role for regulating the tadpole mortality and intoxication by As, Cr and Almix. Overall, our findings demonstrate the different levels of toxic sensitivity (adverse effects) under different toxicants on E. cyanophlyctis tadpoles. Finally, the present findings could be used as baseline information of toxicosis for metalloid, heavy metal and herbicide exposures in wild frog populations.

Present study was designed to evaluate the adverse effect of glyphosate-based herbicide, Excel Mera 71 in Anabas testudineus on comparative basis under field and laboratory conditions. Field (750 g/acre) and laboratory (17.2 mg/L) experiments were performed for a period of 30 days. For field experiment special type of cages were prepared. Fish gill, liver, and kidney were analyzed for histology and ultrastructural responses. A significant increment in morphometric indices (DTC) was observed in gill, liver and kidney of A. testudineus under laboratory condition (p 0.05) and responses showed the degree of pathogenicity in the order of liverkidneygills. However, under field study significant increase in DTC value was observed in gill and liver (p 0.05). Among the scanning electron microscopic (SEM) observations necrosis and loss of microridges, and damage in stratified epithelial cells were prominent in gill, although higher prevalence of alterations was observed under laboratory study than field study. Additionally, transmission electron microscopic (TEM) observations also depicted higher prevalence of pathological lesions under laboratory study compared with field observation. Among the TEM observations damage in chloride and pavement cells, degenerative mitochondria and nucleus (in gill); severe vacuolation, necrosed nucleus and vesiculated network in case of liver and degenerated epithelial cells, cytoplasmic vacuolation, and damage in proximal convoluted tubules (PCT) in case of kidney were prominent. Therefore, these findings demonstrated that Excel Mera 71 induces significant damage in tissues of A. testudineus and these responses might be considered as biomarkers for monitoring herbicidal toxicity on fish in aquatic body.

Oreochromis niloticus was exposed to glyphosate-based herbicide Excel Mera 71 for 30 days under field and laboratory conditions to investigate the histopathological and ultrastructural responses in gill, liver, and kidney. Gill displayed degenerative changes in the pillar cells of gill epithelium, curling of secondary lamella, and appearance of globular structure in laboratory condition under light microscopy. Scanning electron microscopic (SEM) observations revealed loss of microridges, disappearance of normal array of microridges, and damage in stratified epithelial cells under both the conditions, while severe vacuolation and necrosis were prominent under transmission electron microscopic (TEM) study in the laboratory condition. In liver, excess fat deposition and acentric nuclei in the laboratory condition were prominent under light microscopic and SEM study. TEM study showed necrosis in mitochondria, cytoplasmic vacuolation, degeneration in endoplasmic reticulum (ER), and reduced amount of glycogen droplets, but under field condition, lesions were less. Kidney showed fragmented glomerulus, excessive fat deposition, and hypertrophied nuclei under light microscope, while topological study showed shrinkage of glomerulus and degenerative changes under laboratory condition. TEM study also confirmed necrosis in mitochondria, dilation and fragmentation of ER, and appearance of severe vacuolation in the laboratory study, but no significant alterations were observed in field under SEM and TEM study. Therefore, the present study depicts that Excel Mera 71 caused comparatively less pathological lesions under field than laboratory condition, and finally, these responses could be considered as bioindicators for toxicity study in aquatic ecosystem.

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.

Effects of glyphosate-based commercial herbicide, Excel Mera 71 were performed to evaluate the pathological responses in stomach and intestine of Heteropneustes fossilis (Bloch) for duration of 30 days both under rice field and laboratory concentrations. Under light microscopy, stomach showed distortion in columnar epithelial cells (CEC), lamina propria (LP) and gastric glands under both conditions, but the severity of responses were more pronounced under laboratory condition. Severe fragmentation in mucosal folds (MF) and epithelial cells, and excessive mucus secretion were observed under scanning electron microscopic (SEM) study in laboratory study but alterations in stratified epithelial cells and microridges structure were not prominent under field; while deformation in mitochondria and endoplasmic reticulum and cytoplasmic vacuolations were seen under transmission electron microscopic (TEM) observation in both the conditions, but less severe in field study. Intestine showed distortion and fatty deposition in lamina propria, lifting of CEC and loss of brush border structures in laboratory study, while damage only at the tip of the mucosal villi and CEC were observed under field study through light microscopic observation. Under SEM study, degeneration in CEC and excessive mucus secretion over CEC were prominent, while under TEM study deformation and necrosis in mitochondria, severe cytoplasmic vacuolation, necrosis, cytosolic disorganization, and loss of cellular compartmentation were observed in laboratory study, but intestinal epithelium showed normal appearance under field observation. Therefore, present investigation depicted that long-term glyphosate exposure caused stronger pathological alterations under laboratory condition compared with field study and finally, displayed responses could be considered as indicators of herbicidal contamination in aquatic environment.

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.

Present study aimed to investigate the effects of glyphosate-based herbicide, Excel Mera 71 on histopathological and ultrastructural changes in freshwater teleostean fish, Anabas testudineus (Bloch) under field (750 g/acre) and laboratory (17.20 mg/l) conditions for 30 days. In field experiment, fish were reared in special type of cage submerged in pond. Cellular alterations in stomach and intestine were observed through light, scanning and transmission electron microscopy (SEM and TEM). Lesions at the cellular and subcellular levels under field and laboratory conditions were compared. Responses under light microscopy depicted that the symptoms of lesions were more pronounced under laboratory condition than field. Ultrastructural examination also confirmed the observations through SEM and TEM study and the degree of responses in concerned tissues were different under these two conditions. Therefore, evaluation of these histopathological lesions in the concerned tissues may be established as symptomatic indicators for toxicity study in aquatic ecosystem.

Present study aimed to investigate the effects of almix herbicide on histopathological and ultrastructural changes in freshwater teleostean fish, Anabas testudineus (Bloch) under field and laboratory conditions with a dose of 8 g/acre and 66.7 mg/L respectively for 30 days. In field experiment fish species were reared in special type of cage submerged in pond. Cellular alterations of the concerned organs namely gills, liver and kidney were observed through light, scanning and transmission electron microscopy (SEM and TEM). Gill showed hypertrophy and oedema in secondary gill epithelium, and epithelial lifting under laboratory condition but in field condition hyperplasia was prominent. SEM study revealed necrosis, hyperplasia, excessive secretion of mucus and loss of microridges; while TEM study depicted degenerative changes in mitochondria and chloride cells and severe cytoplsmic vacuolation but the changes were comparatively less under field study. In liver, damage in acinar cells of hepatopancreas, degenerative changes in zymogen granules and detachment of hepatopancreatic acinar cells under laboratory condition were the serious changes, but in field condition fatty deposition is prominent. TEM study depicted dilated, degranulated and vesiculated rough endoplasmic reticulum, dilation and swelling of mitochondria and vacuolation in hepatocytes, but under field condition dilation of mitochondria and appearance of vacuolation were well marked. Kidney showed shrinkage of glomerulus, damaged and hypertrophied proximal convoluted tubule, loss of haematopoietic tissues under light microscopy; while ultrastructural changes like degenerative changes in mitochondria, deformed nucleus, dilation, fragmentation and vesiculation of rough endoplasmic reticulum, severe vacuolation in cytoplasm and necrosis were of very serious concern under laboratory condition, but in field condition epithelial cells showed less damage. Responses depicted that symptoms of lesions were more pronounced under laboratory than field condition and the degree of responses in different tissues were different under these two conditions. Therefore, evaluation of these histopathological lesions in concerned tissues may be established as symptomatic indicators for toxicity study in aquatic ecosystem.

Metabolic enzymes such as alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP) were evaluated in Indian teleostean fishes, namely,Anabas testudineus(Bloch) andHeteropneustes fossilis(Bloch), for an exposure to 30 days of Excel Mera 71 (17.2 mg/L), a glyphosate formulation, and subsequent depuration under Liv.52, a plant extract at a dose of 187.5 mg/d/250 L for the same period in the same tissues under laboratory condition. ALT activity was significantly increased (P<0.05) in all the tissues and raised up to 229.19% in liver ofA. testudineus(229.19%) and 128.61% in liver ofH. fossilis. AST also increased significantly (P<0.05) and was maximum in liver ofH. fossilis(526.19%) and minimum in gill ofA. testudineus(124.38%). ALP activity was also raised highly in intestine ofH. fossilis(490.61%) but was less in kidney ofH. fossilis(149.48%). The results indicated that Excel Mera 71 caused alterations in the metabolic enzymatic activities in fish tissues and AST showed the highest alteration in both the fishes, while lowest in ALP and ALT inA. testudineusandH. fossilis, respectively. During depuration under Liv.52, all the enzyme activities came down towards the control condition which indicated the compensatory response by the fish against this herbicidal stress and it was in the following order: AST > ALT > ALP, inA. testudineus, whileH. fossilisshowed the following trend: ALT > AST > ALP. Therefore, these parameters could be used as indicators of herbicidal pollution in aquatic organisms and were recommended for environmental monitoring for investigating the mechanism involved in the recovery pattern.

Effects of glyphosate based herbicide, Excel Mera 71 at a dose of 17.20mg/l on enzyme activities of acetylcholinesterase (AChE), lipid peroxidation (LPO), catalase (CAT), glutathione-S-transferase (GST) and protein content were measured in different tissues of two Indian air-breathing teleosts, Anabas testudineus (Bloch) and Heteropneustes fossilis (Bloch) during an exposure period of 30 days under laboratory condition. AChE activity was significantly increased in all the investigated tissues of both fish species and maximum elevation was observed in brain of H. fossilis, while spinal cord of A. testudineus showed minimum increment. Fishes showed significant increase LPO levels in all the tissues; highest was observed in gill of A. testudineus but lowest LPO level was observed in muscle of H. fossilis. CAT was also enhanced in both the fishes, while GST activity in liver diminished substantially and minimum was observed in liver of A. testudineus. Total protein content showed decreased value in all the tissues, maximum reduction was observed in liver and minimum in brain of A. testudineus and H. fossilis respectively. The results indicated that Excel Mera 71 caused serious alterations in the enzyme activities resulting into severe deterioration of fish health; so, AChE, LPO, CAT and GST can be used as suitable indicators of herbicidal toxicity.

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

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.