Tarakeshwar Senapati

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.

Histopathological and Ultrastructural Alterations in Anabas testudineus Exposed to Glyphosate-Based Herbicide, Excel Mera 71 under Field and Laboratory Conditions

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.

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.

Assessment of adverse outcome of Excel Mera 71 in Anabas testudineus by histological and ultrastructural alterations

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 liver > kidney > gills. 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.

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.