Responses of the freshwater fish Cyprinus carpio exposed to different concentrations of butachlor and oxadiazon

Assessing haematological parameters and probable toxicity analysis in two coastal fish species at harbouring areas of Digha coastal belt, West Bengal, India

Coastal ecosystems are vital for maintaining the biodiversity and human livelihoods, but they are increasingly subjected to anthropogenic pressures, including pollution from various sources. Present work intends to assess the possible threats in coastal ecosystem as well as coastal fish species, in particular, through haematological parameters caused due to exposure of environmental contaminants like polycyclic aromatic hydrocarbons (PAHs), potentially toxic metals (PTMs), etc. This study analysed the haematological parameters and probable toxicity levels in two important coastal fish species, viz., Mystus sp. and Mugil sp. widely available in Digha coastal belt. Different haematological parameters, such as WBCs (White Blood Cells), Lym (Lymphocytes), Gran (Granulocytes), Mid (Monocytes), RBCs (Red Blood Cells), HCT (Haematocrit) value, MCV (Mean Corpuscular Volume), MCH (Mean Corpuscular Haemoglobin), MCHC (Mean Corpuscular Haemoglobin Concentration), RDW- CV (Red Cells Distribution Width-Co-efficient of Variation), RDW- SD (Red Cells Distribution Width-Standard Deviation), PLT (Total Platelet Count), MPV (Mean Platelet Volume), PDW- SD (Platelet Distribution Width-Standard Deviation), PDW- CV (Platelet Distribution Width-Co-efficient of Variation), PCT (Plateletcrit), PLCR (Platelet Large Cell Ratio), PLCC (Platelet Large Cell Count) and many others were measured directly through Erba H360 Haematology Analyser, simultaneously air dried blood smear was stained by Haematoxylin-Eosin(H-E) and Giemsa stain for assessing morphometric alterations of RBCs, WBCs, platelets as well as to determine the differential counts of WBCs by observing through Leica DM2000 microscope. Evidence of several abnormalities in the erythrocyte's nucleus (ENAs) and the abundance of abnormal celled erythrocytes (ECAs), carcinoma (lymphoproliferative disorder, polycythaemia vera, Hodgkin lymphoma and non-Hodgkin lymphoma), elevation of WBCs content, Lym %(Lymphocyte percentage), Eo(Eosinophils), monocytes, HCT and gross depletion of Ne(Neutrophils), basophils, and PLCR levels indicated a sign of major impact of contamination to two intoxicated fishes which may also affect the human being through food chain and may result into leukaemia in mammalian species, finally. However, comprehensive evaluation of the long-term impacts of the contaminants like PAHs and/or PTMs, etc., on fish populations, human health risk and coastal ecosystem is required to be addressed.

Effects of dietary garlic (Allium sativum) oil on growth performance, haemato-biochemical and histopathology of cypermethrin-intoxicated Nile tilapia (Oreochromis niloticus)

BACKGROUND

When pesticides are introduced into wetlands by agriculture, fish quickly absorb them through their gills. Pesticides reduce hatchability, impede growth, and antioxidant response, killing fish. Therefore, it's crucial to find effective pesticide mitigation methods for fish.

OBJECTIVE

In this study, the effects of garlic (Allium sativum) oil on the growth, haematology, biochemistry and histopathology parameters of Nile tilapia (Oreochromis niloticus) exposed to cypermethrin toxicity were investigated.

METHODS

In the research, cypermethrin was added to the water of the experimental groups at a rate of 1:20 of the LC50 value, and 1.00% garlic oil was added to the fish feed. Fish with an initial weight of 30.26 ± 0.26 g were fed for 45 days.

RESULTS

At the end of feeding, the final weights were determined as 69.39 ± 0.41 (G1), 61.81 ± 0.65 (G2), 82.25 ± 0.36 (G3), and 75.04 ± 0.68 (G4) grams, respectively. Histopathological examinations revealed serious lesions in the gill, liver, brain, and muscle tissues in the cypermethrin group, whereas these lesions were minimal or absent in the garlic oil group.

CONCLUSIONS

Garlic oil supplementation had positive effects on growth, haematology, blood biochemistry, hepatosomatic index and histopathological parameters. These findings suggest that garlic oil is a potential protective agent against cypermethrin toxicity.

Occurrence, distribution, and risk assessment of pesticides in surface water and sediment in Jiangsu Province, China

The occurrence and distribution of 157 pesticides were investigated in surface water and sediment in Jiangsu Province, China. Gas chromatography-mass spectrometry was used to analyze and quantify these pesticides, and the risk quotient method was used to evaluate their respective environmental risk. The results showed that 91 pesticides were detected in surface water. The organophosphates (OPPs), fungicides, and amide herbicides were predominant. The total concentration in surface water ranged from 63.7 to 22,463 ng/L, 3.90 to 7262 ng/L, and ND to 34,120 ng/L, respectively. The mean concentration was 3479 ng/L, 1644 ng/L, and 1878 ng/L, respectively. The concentration range of detected pesticides in the Yangtze River Basin was generally lower than that in the Huai River Basin. In sediment samples, a total of 63 pesticides were detected. OPPs and amide herbicides were also ranked highest; the total concentration in sediment samples ranged from 2951 to 47,739 ng/g and 106 to 12,996 ng/g, respectively. And the mean concentrations was 6971 ng/g and 5130 ng/g, respectively. Suqian City had the highest concentration for OPPs and amide herbicides in the Huai River Basin, followed by Huai'an City, while Nanjing City and Yangzhou City ranked highest in the Yangtze River Basin. The spatial distribution of pesticides in Jiangsu Province indicated a concentration significantly higher in the western and northern regions than in the eastern and southern regions, and a concentration generally higher in lakes than in rivers. The risk assessment results showed that OPPs, fungicides, amide herbicides, organochlorines, and triazine herbicides in most surface water samples posed a high risk and had regional pollution characteristics. In sediment samples, organochlorines, carbamates, other herbicides, and other insecticides posed a high risk in northern Jiangsu Province, whereas OPPs, amide herbicides, and triazine herbicides posed high risks everywhere in Jiangsu Province.

Effect of butachlor on Microcystis aeruginosa: Cellular and molecular mechanisms of toxicity

The rapid development of agriculture increases the release of butachlor into aquatic environments. As a dominant species causing cyanobacterial blooms, Microcystis aeruginosa (M. aeruginosa) can produce microcystin and poses threats to aquatic ecosystems and human health. However, the impact of butachlor on M. aeruginosa remains unclarified. Therefore, the physiochemical responses of M. aeruginosa to butachlor were investigated, and the relevant underlying molecular mechanism was highlighted. There were no significant changes (P > 0.05) in the growth and physiology of M. aeruginosa at the low concentrations of butachlor (0-0.1 mg/L), which evidenced a high level of butachlor tolerance in Microcystis aeruginosa. For the high concentrations of butachlor (4-30 mg/L), the inhibition of photosynthetic activity, disruption of cell ultrastructure, and oxidative stress were dominant toxic effects on M. aeruginosa. Additionally, the impaired cellular integrity and lipid peroxidation may be attributed to the substantial elevations of extracellular microcystin-LR concentration. Downregulation of genes associated with photosynthesis, energy metabolism, and oxidative stress was inferred to be responsible for the growth suppression of M. aeruginosa in 30 mg/L butachlor treatment. The upregulation of gene sets involved in nitrogen metabolism may illustrate the specific effort to sustain the steady concentration of intracellular microcystin-LR. These findings dissect the response mechanism of M. aeruginosa to butachlor toxicity and provide valuable reference for the evaluation of potential risk caused by butachlor in aquatic environments.

Spatiotemporal distribution patterns and ecological risk of multi-pesticide residues in the surface water of a typical agriculture area in China

This study systematically investigated the occurrence, spatiotemporal distribution, and ecological risk of 106 pesticides in the surface water of the Jiaodong Peninsula in China. The results show that 52 pesticides, including 21 insecticides, 10 fungicides, and 21 herbicides, were detectable in the surface water. The concentrations of target pesticides in water samples ranged from 0.42 (tebuconazole in the wet season) to 645.31 ng/L (thiamethoxam in the normal season). The two most polluting and widespread pesticides were quintozene (maximum concentration of 481.46 ng/L and detection rate of 94 %) and atrazine (maximum concentration of 465.73 ng/L and detection rate of 100 %). The total pesticide concentrations in surface water in different seasons revealed the order of dry season > wet season > normal season. Based on aquatic pesticide concentrations, their frequency of occurrence, and effect concentrations, insecticides posed higher risks to aquatic organisms and human health than either fungicides or herbicides. Total pesticide concentrations were significantly positively correlated with suspended particulate matter, dissolved organic carbon, soil pH, normalized difference vegetation index, adjacent cropland area; and were negatively associated with adjacent grassland area. The cropland area largely influences pesticide distribution in the surface water of the Jiaodong Peninsula.

Biofloc Technology in Fish Aquaculture: A Review

The application of biofloc to fish species has several advantages, including the enhancement of production by increasing growth performance and survival rate and the improvement of fish aquaculture physiological activity. There has been a recent increase in biofloc addition to fish culture, and this review examines changes this causes to the survival and growth rate of fish and its economic feasibility. Physiological activity and disease resistance of biofloc-fed fish is being extensively studied. The hematological parameters and antioxidant and immune responses of fish fed biofloc were reviewed in this study, as well as their disease resistance by testing them for major specific diseases. Standards for effectively applying biofloc to fish aquaculture are also suggested.

Occurrence, seasonal variations, and eco-risk of currently using organochlorine pesticides in surface seawater of the East China Sea and Western Pacific Ocean

We studied 19 targets currently using organochlorine pesticides (CUOCPs) from 98 samples in the Western Pacific Ocean and the East China Sea collected in 2019, 2020, and 2021. The samples were analyzed using a novel High-throat/High-volume Solid-Phase Extraction method. Eighteen individual CUOCPs were above the method detection limits. The levels of ∑₁₉CUOCPs ranged from 0.13 to 17.80 ng/L, with an average of 3.13 ± 14.67 ng/L. Dicofol was the main pollutant in the Western Pacific Ocean, while Pyridaben dominated the East China Sea. In the summer, land-source input was the primary source in the Western Pacific Ocean and the East China Sea. Historical residues were the main source in the East China Sea in spring. In the summer, the ecological risk assessment results indicated a relatively low risk to the Western Pacific Ocean and the East China Sea.

Integrated biomarker approach strongly explaining in vivo sub-lethal acute toxicity of butachlor on Labeo rohita

Butachlor herbicide belongs to the family of chloroacetanilide group, widely used for control of grass and broadleaf weeds in paddy fields however, its repeated application may result in aquatic pollution. Butachlor residue has been detected in aquatic environments, which may produce toxic effects on non-target organisms including fish. Keeping this in mind, the present study was designed to estimate the LC₅₀ of butachlor (Shaktiman®), and to evaluate the sub-lethal toxicity at two concentrations (12.42 μg L^-1 and 62.10 μg L^-1) in Labeo rohita for a period of 24, 48, and 72 h. Fish exposed to butachlor reduced the counts of red blood cells (RBC), haemoglobin (HGB), hematocrit (HCT), and white blood cells (WBC). A significant (p < 0.05) increase in the antioxidant enzyme (superoxide dismutase-SOD, glutathione-s-transferase-GST), and hepatic enzyme (glutamate-oxaloacetate transaminase-GOT, glutamate-pyruvate transaminase-GPT) were noticed in butachlor exposed fish. Heat shock protein 70 (HSP70) and HSP90 in gill; cortisol, protein, albumin, globulin, and triglyceride in serum were increased upon exposure of butachlor. On the contrary, complement 3 (C3) and immunoglobulin (IgM) in serum was found to be decreased compared to control fish. The findings thus suggest that the fish upon exposure to butachlor disrupts the biomarkers which ultimately leads to growth retardation in fish.

Single and joint toxicity assessment of acetamiprid and thiamethoxam neonicotinoids pesticides on biochemical indices and antioxidant enzyme activities of a freshwater fish Catla catla

Neonicotinoids pesticides are extensively used in many countries due to their high insect selectivity. Acetamiprid and thiamethoxam are the neonicotinoids most commonly detected in the aquatic environment. This work examined the single and joint toxicity of acetamiprid and thiamethoxam in a freshwater fish Catla catla. Fish were exposed to acetamiprid (0.5 mg/L and 1 mg/L), thiamethoxam (0.01 mg/L and 0.5 mg/L) and their binary mixtures (0.5 mg/L of acetamiprid and 0.01 mg/L of thiamethoxam) for 96 h. The stress biomarkers such as glucose, protein, electrolytes, Na⁺/K^{+ -}ATPase and oxidative stress were evaluated. Among the biochemical parameters, plasma protein, electrolytes (sodium, potassium and chloride) and gill ATPase activity were decreased in response to individual and binary mixtures treatments. In contrast, blood glucose level showed significant increase in all the treatments. Exposure to various concentrations of acetamiprid and thiamethoxam resulted in significant decrease in superoxide dismutase (SOD) activity in the gill tissue. However, SOD activity was significantly elevated during binary mixtures treatment. Glutathione peroxidase (GPx), catalase (CAT), glutathione-S-transferase (GST) and reduced glutathione (GSH) levels in gills were decreased significantly after individual and binary mixtures treatments. Fish exposed at individual and binary mixtures significantly elevated the level of LPO in gill tissue. Our findings suggest that multi-biomarker approach can be effectively used to assess the effects of joint toxicity of pesticides and to monitor the neonicotinoids pesticides in the aquatic environment.

Blood Performance: A New Formula for Fish Growth and Health

Simple Summary

The use of haematological and blood biochemistry parameters has proven to be effective and repeatable ways to monitor fish health. Testing these parameters is becoming more common in aquaculture studies. Further, it is widely accepted that fish with better health status are more likely to grow faster as less energy should be consumed for non-growth purposes. Here, a new formula (Blood Performance) is introduced, which contains five common haematological and blood biochemistry parameters: red blood cells, white blood cells, haemoglobin, haematocrit, and total protein. The idea behind this formula is that any single component of this formula cannot be reliable enough as a biomarker of fish health and growth. However, interestingly, Blood Performance can be much more reliable and accurate for monitoring fish health and growth.

Abstract

Monitoring fish health in a repeatable and accurate manner can contribute to the profitability and sustainability of aquaculture. Haematological and blood biochemistry parameters have been powerful tools and becoming increasingly common in aquaculture studies. Fish growth is closely related to its health status. A fish with a higher growth rate is more likely to be a healthy one. Any change in the physiological status of the fish, from pollution to nutritional stress, can cause changes in the blood parameters. Various aquaculture studies have measured the following components: red blood cells, white blood cells, haemoglobin, haematocrit, and total protein. However, because these parameters do not always follow the same trend across experimental fish, it is difficult to draw a firm conclusion about which parameter should be considered. Therefore, Blood Performance (BP) as a new formula is introduced, which is a more reliable indicator. This formula is simple and sums up the natural logarithm of the five above-mentioned parameters. More than 90 published peer-reviewed articles that measured these five parameters in the last six years confirmed the reliability and validity of this formula. Regardless of which supplements were added to the diets, the fish with a higher growth rate had higher BP as well. In addition, in 44 studies out of 53 articles, there was a significant positive correlation between specific growth rate and BP. Under different stressful situations, from pollution to thermal stress, the fish under stress had a lower BP than the control. Fish meal and fish oil replacement studies were further evidence for this formula and showed that adding excessive alternative proteins decreased growth along with BP. In conclusion, BP can be a reliable indicator of fish health and growth when it is compared between groups in the same experiment or farm. Although there was a positive correlation between specific growth rate and BP, comparing BP between experiments is not recommended. Standardising the haematological assays can improve the reliability and accuracy of BP across experiments.

Manifestations of oxidative stress and liver injury in clothianidin exposed Oncorhynchus mykiss

This investigation was conducted to evaluate the effects of clothianidin, a neonicotinoid insecticide, on hepatic oxidative stress biomarkers, biochemical indices of blood serum and liver integrity in juvenile Oncorhynchus mykiss following 7, 14 and 21 days of application to environmentally relevant concentrations of 3, 15 and 30 μg/l. The observed hypertrophy caused elevation in hepatosomatic index, a significant increase in serum glucose and a decrease in tissue protein level with extended period of exposure were determined. The treatment resulted in a marked induction in the activities of antioxidant enzymes which were accompanied with simultaneous elevation in MDA and protein carbonyl level reflecting loss of membrane integrity and protein function. Histopathological examination showed liver injury manifested as hepatocellular degeneration, fibrosis, vacuolation, congestion, necrosis, steatosis and pyknosis proceding with the concentration. The stressful condition triggered hyperglycemic and hypoproteinemic conditions which might be proposed as general adaptive response. Moreover, altered liver histology reveals the hepatotoxic potential of clothianidin via oxidative stress as a common pathological mechanism leading to liver injury.

Tissue-specific toxicity of clothianidin on rainbow trout (Oncorhynchus mykiss)

This study was performed to investigate the tissue-specific effects of clothianidin on Oncorhynchus mykiss by evaluating the biochemical and histological alterations following 21 days of treatment to environmentally relevant concentrations of 3, 15, and 30 µg/L. The emerged behavioral changes in feeding and swimming performance were considered as adaptive responses to avoid the chemical. The toxic effect of pesticide on nervous system and osmoregulation was evidenced with the inhibition of AChE and Na⁺K⁺-ATPase. The sustained lipid peroxidation, ranging from muscle (196%) > brain (154%) > gill (140%) > kidney (129%), might be suggested as a mechanism mediating the inhibition of membrane-bound enzymes. Histological evaluation showed clothianidin-induced lesions appearing as necrosis, atrophy, and edema in muscle, hyperplasia, and hypertrophy causing shortening and fusion of the secondary lamellae in gill, vacuolization, and hydropic degeneration in brain, degeneration of tubular epithelium, and existence of melanomacrophage centers in kidney. The pronounced degenerative changes observed in gill indicate the vulnerability of tissue possibly due to its role as first contact and entry point for the pesticide. Consequently, clothianidin exerted its toxic effects by altering normal behavior, causing neurotoxicity and disturbing osmoregulation. Moreover, the imposed stress was responded in a tissue-specific manner and histological lesions become more severe with increasing concentration. The findings clearly reveal the potential threat caused by environmentally relevant concentrations of clothianidin to early life stages of fish.

Hematological and immunological responses in the African catfish Clarias gairepinus exposed to sublethal concentrations of herbicide Ronstar®

The aim of the study was to investigate the effects of sublethal concentrations (0.3, 0.6 and 1.2 mg L^-1) of the herbicide Ronstar on the hematology and some immune parameters in Clarias gariepinus juvenile (mean weight and length 58.72 ± 2.46 g and 27.60 ± 1.62 cm, respectively). The hematological and some immune parameters were studied for 21 days in a static renewal bioassay system in which the water and the herbicide were changed daily. The erythrocyte count, hemoglobin concentration (Hb), and packed cell volume (PCV) were significantly (p < 0.05) reduced in the treatment groups. When compared with the control, there were significant (p < 0.05) leucocytosis, lymphocytosis, neutropenia and monocytopenia in the treatment groups. Both the mean corpuscular hemoglobin (MCH) and mean corpuscular volume (MCV) were reduced ((p < 0.05) in the Ronstar-exposed fish. The result showed that the treated fish suffered hypochromic microcytic anemia. The total immunoglobulin and phagocytic indices (phagocytic capacity and phagocytic index) were significantly (p < 0.05) reduced in the treatment groups. while the respiratory burst was significantly (p < 0.05) increased in the treatment groups. The result showed that exposure to Ronstar had adverse effects on the hematology and immunocompetency of the fish.

Blood biomarkers of herbicide, insecticide, and fungicide toxicity to fish-a review

Pesticides are widely used in the world agriculture, and they may adversely affect non-target organisms, including fish. The present 2000-2019 literature review summarizes hematological and blood biochemical effects of various herbicides, insecticides, and fungicides in fish. The observed changes usually indicate anemia and inflammation, as well as hyperglycemia, hypoproteinemia, increase in cortisol concentration and activities of hepatic aminotransferases that are typical for intoxication and stress. Other changes that are also sometimes observed such as increase in red blood parameters indicate compensatory response. The often-noted symptoms of immunosuppression show an adverse effect of pesticides on immune system and possible immunosuppression. Pathophysiological changes in fish induced by pesticides depend on many factors, such as active compound and its concentration, exposure duration, fish species, environmental conditions, etc. Hematological and blood biochemical parameters appear to be useful biomarkers for evaluation of physiological state of fish exposed to pesticides; however, they are not specific markers of intoxication.