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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.

This work was aimed to investigate the adverse impacts of Excel Mera 71 on Anabas testudineus, Heteropneustes fossilis and Oreochromis niloticus under laboratory (17.2 mg/L) and field (750 g/acre) conditions based on multiple-level integrated biomarker responses. Haematological parameters were influenced significantly and showed species specificity after Excel Mera 71 exposure under both the conditions. Physiological indices (hepato-somatic index and condition factor) showed higher values; however, hepato-somatic index induced significantly under both the conditions (p H. fossilis > A. testudineus), while total nuclear abnormalities under field showed the order as: H. fossilis (0.49 ± 0.08) > A. testudineus (0.46 ± 0.10) > O. niloticus (0.27 ± 0.05). Moreover, multi-level integrated biomarker responses displayed responses as: O. niloticus (6.97 fold) > H. fossilis (4.01 fold) > A. testudineus (2.33 fold) in laboratory; however, under field condition, responses were totally different [A. testudineus–H. fossilis (3.98 fold) > O. niloticus (3.01 fold)]. Additionally, glyphosate concentration was significantly correlated with several multi-level biomarker responses (p

This study evaluated the acute toxicity and oxidative stress responses to sodium fluoride (NaF) exposure in tadpoles of the skittering frog, Euphlyctis cyanophlyctis (Schneider 1799). The 96 h LC50 value was found to be 647 mg/L. Biochemical tests were conducted at 10%, 20%, 30%, 40%, 50%, 60%, 70% and 80% of the 96 h LC50 dose. Cholinesterase (ChE) activity was unaffected. Lipid peroxidation levels significantly increased (p

Present study was aimed to note the effects of glyphosate-based herbicide, Excel Mera 71 (17.20 mg/L) on digestive enzyme activity in teleostean fishes, Anabas testudineus (Bloch) and Heteropneustes fossilis (Bloch) and their subsequent recovery responses under Liv.52 for a period of 30 days. Amylase activity was raised highly in intestine of A. testudineus (674.07%) and was lowest in liver of H. fossilis (180.14%). Lipase activity showed highest elevation in liver of H. fossilis (182.14%) and lowest in intestine of A. testudineus (70.77%). Highest elevation of protease activity was observed in intestine of H. fossilis (376.92%) but was lowest in liver of A. testudineus (138.46%). During depuration phase, these enzyme activities significantly came down towards the control value which indicated compensatory responses against herbicidal toxicosis. Therefore, it can also be inferred that these responses of A. testudineus and H. fossilis to Excel Mera 71 and Liv.52 exposures could be considered as biomarkers against herbicidal toxicosis in aquatic ecosystem, although it needs further studies on mechanistic pathway to investigate the detailed mechanism involved in recovery responses.

In the present study, multi-level integrative biomarker responses (multi-level IBR) were studied to evaluate the toxicological effects of Almix herbicide towards Indian teleosts, namely Anabas testudineus, Heteropneustes fossilis and Oreochromis niloticus under laboratory (66.7 mg/L) and field (8 g/acre) conditions (30 days). At physiological level, condition factor (CF) displayed significant increase (p O. niloticus (0.31 ± 0.06) > A. testudineus (0.23 ± 0.03)]. However, in field study, the degree of ENA were H. fossilis (0.14 ± 0.03) > O. niloticus (0.11 ± 0.04) > A. testudineus (0.09 ± 0.03). Additionally, multi-level IBR index indicating the degree of severity as of H. fossilis (6.97-fold) > A. testudineus (threefold) > O. niloticus (twofold) under laboratory condition, while in field study, it was H. fossilis (4.98-fold) > A. testudineus (twofold) > O. niloticus (1.67-fold). However, higher IBR index value in laboratory study indicated more severe adverse effects of Almix intoxication than field study, although varied multi-level IBR index under different conditions suggested the different contamination level. Therefore, these findings infer that multi-level IBR index might serve as a useful tool for quantitative monitoring of toxicological effects.

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.

Stratification and assessment of the limnological conditions of an abandoned opencast coal pit (OCP), locally called Khadan, which is a potential water reserve located at the Raniganj-Asansol Coalfield Areas of Burdwan, are the main objectives of this study. Water quality changes occurred with increasing depths in the OCP water and suggest a gradual and significant ecological restoration over time, which can create a condition of sustainable pisciculture. The physical and chemical variables of the OCP water changed with changing depths and seasons. The temperature and alkalinity decreased with depth throughout the year. The dissolved oxygen concentration exhibited a mixing characteristic in the summer and winter, but decreased with depth in the monsoon and postmonsoon seasons. The total hardness increased with depth in the monsoon season, being maximum in the winter (196.0 mg L−1). The biochemical oxygen demand (BOD) and chemical oxygen demand (COD) increased with depth in the winter. The silicon concentration increased with depths, exhibiting a maximum value of 14.2 mg L−1 in the winter and a minimum value of 1.24 mg L−1 in the postmonsoon season. The ammonia-nitrogen, nitrate-nitrogen, potassium, chloride and sulphate concentrations only exhibited seasonal variations. The concentration of heavy metals (arsenic, chromium, cadmium, manganese) decreased with increasing depth. The fluoride concentration exhibited high concentrations in each OCP water layer. The results of this study indicated that limnological variables in thermally stratified lakes may be an important measure for better understanding the gradual process of developing an improved ecological conditions in the OCP and which can facilitate the possibility of pisciculture in the near future.

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.

Three freshwater teleostean fishes viz., Anabas testudineus (Bloch), Heteropneustes fossilis (Bloch) and Oreochromis niloticus (Linnaeus) were exposed to almix (66.67 mg/l) herbicide for 30 days to investigate the activity of digestive enzymes (amylase, lipase and protease) in stomach, intestine and liver. Amylase activity showed significantly high (p A. testudineus > H. fossilis.

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.

Three Indian freshwater teleostean fishes Anabas testudineus, Heteropneustes fossilis and Oreochromis niloticus were exposed to almix (66.67 mg/l) under laboratory condition for a period of 30 days to investigate the activity of transaminases (alanine aminotransferase (ALT), aspartate aminotransferase (AST)), and phosphatase (alkaline phosphatase (ALP)) in the gill, intestine, heart and muscle tissues. ALT levels showed significant elevation (p H. fossilis > A. testudineus. Therefore, assessment of these metabolic enzymes in tissue systems is important for evaluation of the herbicidal contamination like almix on fish species.

Activities of three enzymes in liver viz., aspartate aminotransferase (AST), alanine aminotransferase (ALT) and alkaline phosphatase (ALP) in three Indian teleosts, Anabas testudineus,Heteropneustes fossilis, and Oreochromis niloticus exposed to a dose of 66.67 mg/l Almix 20 WP herbicide for a period of 30 days are reported here. The study revealed that the total protein content in liver was reduced significantly (p < 0.05) in H. fossilis (Mean ± SEM, 63.82 ± 4.33 to 34.50 ± 0.83 mg/g) but minimum in A. testudineus (53.29 ± 3.33 to 42.11 ± 1.83 mg/g). AST and ALT activities were significantly (p < 0.05) increased and highest in O. niloticus (154.99 ± 2.51 to 716.99 ± 4.09 and 97.67 ± 1.22 to 144.64 ± 6.84 unit/mg protein respectively), while minimum activity was noted in H. fossilis (88.44 ± 1.97 to 147.55 ± 2.72 unit/mg protein) and A. testudineus (87.51 ± 2.98 to 129.31 ± 2.87 unit/mg protein) respectively. ALP activity showed significant (p < 0.05) increment in H. fossilis (12.66 ± 1.26 to 18.24 ± 1.05 unit/mg protein), while less in O. niloticus (31.68 ± 1.41 to 38.01 ± 0.93 unit/mg protein) and moderate in A. testudineus. Enhanced levels of both aminotranferases and ALP indicated that liver was damaged excessively by almix exposure. The results also disclosed that O. niloticus was more sensitive than other two fishes and from these alterations it can be inferred that hepatic AST, ALT and ALP activity could be a diagnostic tool and considered as the indicators of herbicide toxicity in an aquatic environment.

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.

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

Objective: Present study was aimed to study the cytopathological effects of almix herbicide in Indian freshwater teleost, Oreochromis niloticus (Linn.) both under field and laboratory exposure. Methods: O. niloticus (Linn.) was exposed to almix herbicide at sublethal concentrations of 8 g/acre and 66.67 mg/L under field and laboratory conditions respectively for 30 days. Field experiment was performed in cage, submerged in the field pond. Cytopathological study both through light and electron microscopic (scanning electron microscopy and transmission electron microscopy) observations were based on gill, liver and kidney. Results: Histopathological observations revealed hypertrophy and proliferation in gill epithelium, curling and fusion of secondary gill lamellae (SGL), distortion in chloride and pillar cells under laboratory experiment. Scanning electron microscopy displayed severe loss of normal array of concentric microridges, swelling of microridges, damage in epithelial cells and appearance of vacuoles on the stratified epithelium, while loss of regular pattern of microridges were observed under field condition. Transmission electron microscopic study of gill showed severe damages which included degenerative changes in mitochondria, cellular vacuolation, damage in tubule vascular system, presence of lipid droplets, elongated nucleus, but in case of field experiment dilated mitochondria and cytoplasmic vacuolation were more prominent. Degenerative hepatopancreas, necrosis in hepatocytes, severe cytoplasmic vacuolation and disarrangement of hepatic cords in liver of O. niloticus were prominent seen under light microscopy in the laboratory condition, but in field condition elongated hepatocytes with increased nuclei and vacuolation in cytoplasm of hepatocytes were prominent, while TEM study showed degeneration in mitochondria, dilation in rough endoplasmic reticulum, damage in nucleus and appearance of cytoplasmic vacuolation in hepatocytes under laboratory condition. In kidney, degenerative changes in PCT and DCT, shrinkage of glomerulus, vacuolation in the haematopoietic tissues and excess fat deposition were notable changes. In TEM study necrosis in nucleus, severe vacuolation, appearance of endoplasmic reticulum as whorl pattern, degeneration in mitochondria in kidney were serious after almix exposure. Conclusion: Present study claimed the more profound responses under laboratory condition compared to field and different significant marked changes in these two conditions were prominent. Therefore, these responses in gill, liver and kidney of O. niloticus could be considered as potential of exposure of agrochemicals.

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.

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.

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.