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Aim. The aim of the study was to compare the specificity and sensitivity of responses of stress and toxicity to Cpz in marine and freshwater species of bivalve molluscs. Methods. The bivalve molluscs Mytilus galloprovincialis and Unio tumidus were collected in Messina, Italy and Ternopil region, Ukraine correspondingly. Two low Cpz concentrations (Cpz I: 12 ng L–1; Cpz II: 12 (M. galloprovincialis) or 18 (U. tumidus) μg L–1) were administered to molluscs for 14 days. The set of 16 studied parameters included the cytotoxicity indexes (lysosomal membrane stability, apoptotic enzymes caspase-3 and cathepsin D (CtD)), o xidative/reductive stress responses (superoxide dismutase (SOD) and catalase (CAT) activities, the levels of protein carbonyls (PC) and products of lipid peroxidation (TBARS), glutathione (GSH&GSSG), NAD+&NADH), metallothionein (total and Zn-bound) concentration, the biotransformation enzymes CYP450-dependent EROD, glutathione S-transferase (GST), and GTP-ase dynamin in the digestive gland with some inter-species differences in this spectrum. The applied spectrophotometric and chromatographic methods are described thoroughly in our previous work [6]. Results and Discussion. In the hepatocytes of rat, Cpz causes the biotransformation upregulation [7]. In our study, the activity of EROD increased both in M. galloprovincialis and U. tumidus, depending on the concentration and, particularly, in the Cpz II group of U. tumidus (by three times). This conversion of Cpz can result in the reactive metabolite formation [7]. According to this data, the inhibition or absence of the changes in the EROD activity in the Cpz I group of U. tumidus and Cpz II group of M. galloprovincialis can delay Cpz toxicity. On the other hand, the toxic product of biotransformation, quinoneimine is known to be eliminated by the GSH-dependent GST which activity was increased up to 63% in the Cpz I and II groups of marine mussels. Since in the freshwater mussels GST activity decreased in both exposures, the higher toxicity of Cpz was expected. Moreover, the GTP-ase dynamin activation in the Cpz I group of U. tumidus confirms the impact of this pharmaceutical on the clathrin-dependent endocytosis [8]. Conclusions. Summarizing, adverse outcome pathways related to the effect of Cpz on vertebrates in the μM concentration, were indicated in the mussels under the pM — nM concentrations with distinct inter-species concentration-related dependence, and the responses of stress were similar in both species. Particularly, marine molluscs can be a perspective model for evaluating Cpz adverse effects intrinsic for the higher vertebrates. [ABSTRACT FROM AUTHOR]

Benzisothiazolinone (BIT) is a preservative and antimicrobial agent widely used in various household and industrial products. It is readily detectable in pesticides, polishes, printing inks and detergents. This extensive use is reflected in a vast amount of this compound in the environment, which may cause toxic effects in organisms that come in contact with it. In light of the aforementioned context, this work aims to investigate the potential cellular and physiological impact on aquatic organisms through in vitro tests, utilising haemocytes and digestive gland (DG) cells derived from the Mediterranean mussel (Mytilus galloprovincialis). Two different concentrations (B1: 0.03 µg/L; B2: 0.3 µg/L) were tested at two different times of exposure (T1: 1 h; T2: 3 h) to evaluate the viability of cells, the phagocytic activity (haemocytes), the regulation volume decrease (RVD on DG cells) capability. Moreover, the cytoprotective mechanisms related to oxidative stress and detoxification were evaluated through the expression analysis by qPCR of key genes involved in these pathways. The most significant results obtained from these tests were the reduction of viability of haemocytes at T2 of exposure to B2, a decrease of vitality in DG cells exposed to B1 during the T1, the significant alteration in the phagocytosis activity, the upregulation of Cu/ZnSOD gene, the inhibition of the CYPY1 gene expression and upregulation of the Heat shock protein 70 (Hsp70) gene following the BIT exposure. These findings provide a valuable foundation for further investigation, offering insights into the potential impact of BIT on aquatic communities., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Inc.)

After the COVID-19 pandemic, the use of quaternary ammonium compounds increased exponentially due to their efficacy as antimicrobials, stabilizers and disinfectants. Among these, Quaternium-15 is a preservative used in the formulation of a variety of personal care products. The increased use of this substance and the resulting persistence in wastewater treatment systems, which are unable to completely remove the Quaternium-15 from the water, is of increasing environmental concern. Using embryotoxicity analyses, this study aimed to investigate the effects of exposure to Quaternium-15 on non-target species and the resulting risks to the environment. Embryotoxicity endpoints such as mortality, hatching, presence of malformations, altered heartbeat and animal length were used to assess the effects on three model organisms (Cyprinus carpio, Danio rerio, Xenopus laevis) were evaluated during a 96-hour exposure to six different concentrations of Quaternium-15 (1, 5, 10, 15, 20 and 25 mg/L). The results obtained from the analyses highlighted: significant mortality for all three model organisms in the highest concentrations tested in which all the embryos died after 96 hpf, a delay in hatching of C. carpio and D. rerio compared to the control group, the insurgence of malformations in all the model organisms chosen and a significant decrease in heartbeat rate for the fish models. Each of these observations underlies the negative interaction between the Quaternium-15 and aquatic organisms making necessary further investigation to prevent damage to ecosystems and non-target species., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier B.V. All rights reserved.)

The zinc oxide nanoparticles (ZnO-NPs) being widely employed in several industries and consumer products, are raising concerns about their safety on aquatic biota and human health. This study aims to investigate the possible toxicological effects of ZnO-NPs through a combined in vivo and in silico approach. Zebrafish embryos were exposed to several ZnO-NPs concentrations and morphological alterations and lipid peroxidation (MDA) were investigated. Furthermore, molecular docking simulations were applied to study the intermolecular interactions of ZnO-NPs against critical embryonic proteins namely zebrafish hatching enzyme1 (ZHE1) as well as the superoxide dismutase (SOD1). Treatment with ZnO-NPs resulted in an increase in MDA concentration and a decrease in antioxidant enzyme levels. Besides a significant decrease in mRNA expression of key enzymes of ROS detoxification genes, a modulation of inflammatory genes with a low downregulation of tnf-α, and an upregulation of il-1β were observed. Docking study suggests that the delayed hatching and increased cellular oxidative stress in zebrafish embryos may occur through a synergistic mechanism based on the ZnO-NP-dependent inhibition of ZHE1 and SOD1 enzymes. The integration of in vivo assessments with in silico computational modeling provided a more comprehensive evaluation of potential physiological risks in zebrafish embryos associated with nanomaterial exposure., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Valbona Aliko reports financial support was provided by Albanian Academy of Sciences. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Improper disposal of household and industrial waste into water bodies has transformed them into de facto dumping grounds. Plastic debris, weathered on beaches degrades into micro-particles and releases chemical additives that enter the water. Microplastic contamination is documented globally in both marine and freshwater environments, posing a significant threat to aquatic ecosystems. The small size of these particles makes them susceptible to ingestion by low trophic fauna, a trend expected to escalate. Ingestion leads to adverse effects like intestinal blockages, alterations in lipid metabolism, histopathological changes in the intestine, contributing to the extinction of vulnerable species and disrupting ecosystem balance. Notably, microplastics (MPs) can act as carriers for pathogens, potentially causing impaired reproductive activity, decreased immunity, and cancer in various organisms. Studies have identified seven principal sources of MPs, including synthetic textiles (35%) and tire abrasion (28%), highlighting the significant human contribution to this pollution. This review covers various aspects of microplastic pollution, including sources, extraction methods, and its profound impact on ecosystems. Additionally, it explores preventive measures, aiming to guide researchers in selecting techniques and inspiring further investigation into the far-reaching impacts of microplastic pollution, fostering effective solutions for this environmental challenge., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

In the last decades, pharmaceuticals have emerged as a new class of environmental contaminants. Antihypertensives, including angiotensin-converting enzyme (ACE) inhibitors, are of special concern due to their increased consumption over the past years. However, the available data on their putative effects on the health of aquatic animals, as well as the possible interaction with biological systems are still poorly understood. This study analysed whether and to which extent the exposure to Enalapril, an ACE inhibitor commonly used for treating hypertension and heart failure, may induce morpho-functional alterations in the mussel Mytilus galloprovincialis, a sentinel organism of water pollution. By mainly focusing on the digestive gland (DG), a target tissue used for analysing the effects of xenobiotics in mussels, the effects of 10-days exposure to 0.6 ng/L (E1) and 600 ng/L (E2) of Enalapril were investigated in terms of cell viability and volume regulation, morphology, oxidative stress, and stress protein expression and localization. Results indicated that exposure to Enalapril compromised the capacity of DG cells from the E2 group to regulate volume by limiting the ability to return to the original volume after hypoosmotic stress. This occurred without significant effects on DG cell viability. Enalapril unaffected also haemocytes viability, although an increased infiltration of haemocytes was histologically observed in DG from both groups, suggestive of an immune response. No changes were observed in the two experimental groups on expression and tissue localization of heat shock proteins 70 (HSPs70) and HSP90, and on the levels of oxidative biomarkers. Our results showed that, in M. galloprovincialis the exposure to Enalapril did not influence the oxidative status, as well as the expression and localization of stress-related proteins, while it activated an immune response and compromised the cell ability to face osmotic changes, with potential consequences on animal performance., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

The aim of this study is to evaluate the toxic effects of different concentrations of cigarette butt leachate (CBL) (0.0, 0.5, 1, 1.5, and 2.0 µL L -1 ) on blood biochemistry, oxidative stress biomarkers, and the biochemical profile of the liver and muscle of Nile tilapia fish (Oreochromis niloticus) after 21 days. Increased activity of lactate dehydrogenase (LDH), gamma-glutamyl transferase (GGT), and aspartate aminotransferase (AST) in plasma, and decreased activity of alkaline phosphatase (ALP) in fish exposed to CBL, indicated cytotoxicity. Elevated cholesterol, triglycerides, and glucose levels, coupled with reduced total protein, albumin, and globulin levels in the plasma, indicated impaired liver function in the fish. An increase in creatinine showed kidney damage. Increased superoxide dismutase (SOD), glutathione peroxidase (GPx), and catalase (CAT) activities, along with the decrease in liver glutathione (GSH) content and total antioxidant capacity in the hepatocytes of fish exposed to CBL, indicated the occurrence of oxidative stress. Malondialdehyde (MDA) elevation indicated heightened lipid peroxidation in CBL-exposed fish hepatocytes. Raman spectroscopy revealed altered biochemical profiles in fish liver and muscle post-CBL exposure. The results demonstrated that exposure to CBL led to a decrease in phospholipid levels, collagen destruction, changes in phenylalanine levels, and a decrease in the levels of lipids, proteins, and nucleic acids in fish liver and muscle tissue. Furthermore, the metabolites and compounds of cigarette butt juice were detectable in the liver and muscle tissue of fishes. In conclusion, this study showed that exposure to CBL can have adverse effects on fish health., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Pharmaceutical and personal care products (PPCPs) containing persistent and potentially hazardous substances have garnered attention for their ubiquitous presence in natural environments. This study investigated the impact of polyethylene glycol (PEG), a common PPCP component, on Mytilus galloprovincialis . Mussels were subjected to two PEG concentrations (E1: 0.1 mg/L and E2: 10 mg/L) over 14 days. Oxidative stress markers in both gills and digestive glands were evaluated; cytotoxicity assays were performed on haemolymph and digestive gland cells. Additionally, cell volume regulation (RVD assay) was investigated to assess physiological PEG-induced alterations. In the gills, PEG reduced superoxide dismutase (SOD) activity and increased lipid peroxidation (LPO) at E1. In the digestive gland, only LPO was influenced, while SOD activity and oxidatively modified proteins (OMPs) were unaltered. A significant decrease in cell viability was observed, particularly at E2. Additionally, the RVD assay revealed disruptions in the cells subjected to E2. These findings underscore the effects of PEG exposure on M. galloprovincialis . They are open to further investigations to clarify the environmental implications of PPCPs and the possibility of exploring safer alternatives.

The antipsychotic chlorpromazine (Cpz) has raised concern as a pharmaceutical effluent due to its wide medical applications. Moreover, its potent pro-oxidant properties and impact on the cell viability of the marine mollusc Mytilus galloprovincialis, even at low concentrations (ng/L), have been noted. Based on this evidence, in this study, we investigated the physiological effects of Cpz on M. galloprovincialis, to elucidate its fate within the organism, in terms of bioaccumulation, biotransformation, byssus changes and stress responses of the cellular thiolome. Histological and indicators of vitality analyses were also performed to better evaluate the influence of the drug on the morphology and cell viability of the digestive gland. To this end, two different concentrations of Cpz (Cpz I (12 ng/L or 37 pM) and Cpz II (12 μg/L or 37 nM)) were administered to mussels over 14 days. Cpz accumulation in the digestive gland significantly increased with water concentration (BCF of Cpz I and Cpz II). Biochemical analyses indicated lysosomal dysfunction, reflected in elevated total Cathepsin D activity and compromised lysosomal membrane stability. Stress-related and metal-buffering proteins (GST and metallothionein) responded to both Cpz concentrations. Cpz I induced phase I biotransformation activity (CYP450-dependent EROD), while Cpz II triggered caspase-3 activation, indicative of detoxification overload. Histological analysis revealed digestive gland atrophy, epithelial thinning, haemocyte infiltration, and brown cell presence. Byssus analysis showed significant alterations. In conclusion, our study underscores Cpz-induced physiological and histological changes in M. galloprovincialis, posing potential implications for mussel health and confirming the utilisation of this mussel as an indication of Cpz ecotoxicity., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Authors. Published by Elsevier Ltd.. All rights reserved.)

Pleurotus florida (Mont.) Singer is a mushroom species known to be an antioxidant, immunomodulatory, and diuretic agent, reducing blood pressure and cholesterol. The aim of this study was to evaluate the in vivo potency of P. florida's anti-diabetic properties in rats affected by hyperglycemia induced by Streptozotocin (STZ) at 55 mg/kg (i.p.), characterized by oxidative stress impairment, and changes in insulin levels and lipid profile. After inducing hyperglycemia in the rats, they were treated with P. florida acetone and methanol extracts, orally administered for 28 days at doses of 200 mg/kg and 400 mg/kg body weight. The hyperglycemic control (DC) group showed significant increases (P < 0.05) in mean blood sugar, total cholesterol, triglycerides, low-density lipoprotein cholesterol, very low-density lipoprotein cholesterol, blood urea nitrogen, lipid hydroperoxides, and malondialdehyde, compared to the normal control (NC) group The high-density lipoprotein cholesterol, serum insulin, superoxide dismutase, catalase, glutathione disulfide, glutathione peroxidase, reduced glutathione, guaiacol peroxidase, and vitamin E and C levels showed a significant decrease (P < 0.05) in DC group, compared to the NC group. Blood glucose levels, lipid profiles, and insulin levels improved significantly after 28 days of treatment, in the group treated with glibenclamide (an oral hypoglycemic drug, used as positive control), and in the groups treated with P. florida extracts. In DC group, the treatment with P. florida was found to prevent diabetes, according to histopathological studies of the kidneys, pancreas, and liver of rats. In conclusion, this study has shown that the treatment with P. florida decreased oxidative stress and glucose levels in the blood, as well as restoring changes in lipid profiles., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Authors. Published by Elsevier Masson SAS.. All rights reserved.)

Introduction: Bivalve molluscs like Mytilus galloprovincialis are valuable bioindicators due to their filter-feeding lifestyle, wide distribution, and ability to concentrate xenobiotics. Studying the effects of pharmaceuticals on these molluscs is crucial given their presence in surface waters. This study investigated the response of M. galloprovincialis to chlorpromazine (Cpz), an antipsychotic with antiviral activity against influenza, HIV, and coronaviruses in human cells. Methods: In this study, we examined the 14-day impact of chlorpromazine (Cpz) on the model species M. galloprovincialis at two concentrations (Cpz 1: 12 ng L-1 or 37 pM; Cpz 2: 12 µg L-1 or 37 nM). To ensure controlled exposure, a stock solution of Cpz was prepared and introduced into the tanks to match the intended concentrations. Seawater and stock solutions were refreshed every 48 h. The primary focus of this study centered on evaluating cell viability, cell volume regulation, and oxidative stress indicators. Results: Although cell volume regulation, as assessed by decreasing regulatory volume Regulation volume decrease, did not show statistically significant changes during the experiment, digestive cell viability, on the other hand, showed a significant decrease ( p < 0.01) in the Cpz 2 group, suggesting effects on the general health and survival of these cells. Biochemically, in both Cpz 1 and Cpz 2, superoxide dismutase activity increased, while catalase (CAT) decreased, causing an elevated lipid peroxidation thiobarbituric acid-reactive substances and protein carbonyls, particularly in the Cpz 2 group. The level of reduced glutathione (GSH) increased in both exposures, whereas the level of GSSG increased only in the Cpz 1 group. Consequently, the GSH/GSSG ratio was elevated in the Cpz 2 group only. Discussion: A comparison of the magnitudes of anti- and pro-oxidative manifestations indicated a pro-oxidative shift in both exposures. These findings show that Cpz induces non-specific symptoms of biochemical and cellular disturbances in M. galloprovincialis even at the low picomolar concentration., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest. The author(s) declared that they were an editorial board member of Frontiers, at the time of submission. This had no impact on the peer review process and the final decision., (Copyright © 2023 Impellitteri, Yunko, Martyniuk, Khoma, Piccione, Stoliar and Faggio.)

Due to their uncontrolled use, plastics has become an environmental concern, not only for their varying dimension but also for the potential release of substances such as phthalates (PAEs) and non-phthalates (NPPs) into the water. Phthalates are the most common plasticizers of concern, but non-phthalate plasticizers such as di (2-ethylhexyl) terephthalate (DEHT) have also been lately found in the marine environment. Mytilus galloprovincialis is a well-known bioindicator of aquatic environments due to its ability to accumulate a wide variety of xenobiotics, including plasticizers. Hence, aim of this study was to evaluate the potential bioaccumulation and effects of the NPP DEHT on M. galloprovincialis. To this purpose, following exposure to DEHT at 1 mg/l (DEHT1) and 100 mg/l (DEHT100), its accumulation in tissues and its effects on total lipids and fatty acid (FA) composition, protein content, cell viability, ability to recover volume and changes in biomarkers of oxidative stress were assessed. Mussels were able to bioaccumulate DEHT in their tissues, with a statistically significant increase compared to the control organisms. Differences in FA composition were observed after exposure, since C16:0, C18:0, C20:5ω-3 and C22:6ω-3 were significantly decreased from control to exposed groups. As a result, total SFA, MUFA and PUFA were affected in DEHT-exposed groups. Also, total protein varied following DEHT exposure, and significantly decreased in the DEHT100-group. Considering the physiological responses, both DEHT-exposed groups lost their ability to return to the original volume of digestive gland (DG) cells. On the other hand, oxidative biomarkers in the gills and DG were not significantly affected by the DEHT exposure. Overall, this study showed for the first time that DEHT exposure differentially affect mussels, in their lipid and protein metabolism, as well as cellular parameters., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

This study aimed to investigate the effects of diazinon on fish, focusing on hepatotoxic biomarkers and the potential protective effects of silymarin supplementation. One hundred eighty rainbow trout were randomly assigned to four groups: control, diazinon exposed (0.1 mg L -1 ), silymarin supplemented (400 mg kg -1 ), and diazinon + silymarin. Blood samples and liver tissue were collected after 7, 14, and 21 days of exposure to analyze biochemical parameters and oxidative biomarkers. Diazinon exposure in fish resulted in liver damage, as indicated by increased antioxidant enzyme activities in the hepatocytes. Silymarin showed the potential to mitigate this damage by reducing oxidative stress and restoring enzyme activities. Nevertheless, diazinon increased creatine phosphokinase activity, which may not be normalized by silymarin. Exposure to diazinon increased glucose, triglyceride, and cholesterol levels, whereas total protein, albumin, and globulin levels were significantly decreased in fish. However, silymarin controlled and maintained these levels within the normal range. Diazinon increased creatinine, urea, uric acid, and ammonia contents. Silymarin could regulate creatinine, urea, and uric acid levels while having limited effectiveness on ammonia excretion. Furthermore, diazinon increased malondialdehyde in hepatocytes, whereas administration of silymarin could restore normal malondialdehyde levels. Overall, silymarin showed potential as a therapeutic treatment for mitigating oxidative damage induced by diazinon in fish, but its effectiveness on creatine phosphokinase, glutathione reductase, and ammonia may be limited.

The lack of data on the chronic effects of chloroacetanilide herbicide metabolites on non-target aquatic organisms creates a gap in knowledge about the comprehensive impacts of excessive and repeated pesticide use. Therefore, this study evaluates the long-term effects of propachlor ethanolic sulfonic acid (PROP-ESA) after 10 (T1) and 20 (T2) days at the environmental level of 3.5 μg.L -1 (E1) and its 10x fold multiply 35 μg.L -1 (E2) on a model organism Mytilus galloprovincialis. To this end, the effects of PROP-ESA usually showed a time- and dose-dependent trend, especially in its amount in soft mussel tissue. The bioconcentration factor increased from T1 to T2 in both exposure groups - from 2.12 to 5.30 in E1 and 2.32 to 5.48 in E2. Biochemical haemolymph profile and haemocyte viability were not affected by PROP-ESA exposure. In addition, the viability of digestive gland (DG) cells decreased only in E2 compared to control and E1 after T1. Moreover, malondialdehyde levels increased in E2 after T1 in gills, and DG, superoxidase dismutase activity and oxidatively modified proteins were not affected by PROP-ESA. Histopathological observation showed several damages to gills (e.g., increased vacuolation, over-production of mucus, loss of cilia) and DG (e.g., growing haemocyte trend infiltrations, alterations of tubules). This study revealed a potential risk of chloroacetanilide herbicide, propachlor, via its primary metabolite in the Bivalve bioindicator species M. galloprovincialis. Furthermore, considering the possibility of the biomagnification effect, the most prominent threat poses the ability of PROP-ESA to be accumulated in edible mussel tissues. Therefore, future research about the toxicity of pesticide metabolites alone or their mixtures is needed to gain comprehensive results about their impacts on living non-target organisms., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier Ltd. All rights reserved.)

Since the 2000 s, the pearl oyster Pinctada imbricata (Röding, 1798) has become established along the transitional waterways of the "Capo Peloro Lagoon" natural reserve, where it is now abundant due to its adaptability to different hydrological, climatic, environmental, and pollution conditions. This study aims to evaluate haemocyte immune-mediated responses in vitro to quaternium-15, a common pollutant in aquatic ecosystems. Cell viability and phagocytosis activity decreased when exposed to 0.1 or 1 mg L - 1 of quaternium-15. Moreover, decreasing phagocytosis was confirmed by gene expression modulation of actin, involved in cytoskeleton rearrangement. Effects on oxidative stress-related genes were also assessed (Cat, MnSod, Zn/CuSod, GPx). The qPCR data revealed alterations in antioxidant responses through gene dose- and time-dependent modulation. This study presents insights into the physiological responses and cellular mechanisms of P. imbricata haemocytes to environmental stressors, indicating that this species is useful as a novel bioindicator for future toxicological studies., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

In this historical context, the Mediterranean Sea faces an increasing threat from emerging pollutants such as pharmaceuticals, personal care products, heavy metals, pesticides and microplastics, which pose a serious risk to the environment and human health. In this regard, aquatic invertebrates and fish are particularly vulnerable to the toxic effects of these pollutants, and several species have been identified as bio-indicators for their detection. Among these, bivalve molluscs and elasmobranchs are now widely used as bio-indicators to accurately assess the effects of contaminants. The study focuses on the catshark Scyliorhinus canicular and on the Mediterranean mussel Mytilus galloprovincialis . The first one is a useful indicator of localised contamination levels due to its exposure to pollutants that accumulate on the seabed. Moreover, it has a high trophic position and plays an important role in the Mediterranean Sea ecosystem. The bivalve mollusc Mytilus galloprovincialis , on the other hand, being a filter-feeding organism, can acquire and bioaccumulate foreign particles present in its environment. Additionally, because it is also a species of commercial interest, it has a direct impact on human health. In conclusion, the increasing presence of emerging pollutants in the Mediterranean Sea is a serious issue that requires immediate attention. Bivalve molluscs and elasmobranchs are two examples of bio-indicators that must be used to precisely determine the effects of these pollutants on the marine ecosystem and human health.

Chlorpyrifos is an organophosphate insecticide occurring in aquatic ecosystems. Due to exposure to xenobiotics, several harmful effects on aquatic organisms are noticed worldwide. Mangrove crabs are an ecologically important aquatic invertebrate species in food web interactions and in the mangrove ecosystem. Therefore, this study aimed to evaluate the cytotoxic effects of chlorpyrifos on the mangrove crab, Episesarma tetragonum . Crabs were exposed to 0.0294 and 0.0588 ppm of chlorpyrifos for 7 and 28 days. Cytopathologic effects on the gill, hepatopancreas, and muscle were investigated, and observations were compared with a control group. The results suggest that chlorpyrifos induces time- and concentration-dependent cytopathological alternations in the gill and exhibited epithelial lifting, oedema, necrosis, and a fusion of secondary lamellae and haemorrhage. The deceased hepatopancreas showed infiltration, a large lumen formation, and the disappearance of haemocytes, while the muscle tissue showed atrophy, necrosis, a wavy appearance, an accumulation of granular material between muscle fibres, and fragmentation in a mangrove crab. This study shows the great potential of cytopathological investigations, allows us to assess the sensitivity of various aquatic animal species to potentially dangerous compounds, and calculates safe concentrations with which to reduce pesticide use.

Invertebrates have long been an important tool for assessing water pollution due to their characteristics as intermediate consumers in aquatic ecosystem food chains. Most of the time, the effects of contaminants are measured by their effect on oxidative status or by mortality, although there already exists an easier tool-hemocytes. Hemocytes are circulating cells with a very important role in the immune system of invertebrates, which can be found within the hemolymph, analogous to the blood in vertebrates. The collection of hemolymph samples is easy, fast, minimally invasive, and poses no danger to the life of invertebrates. The purpose of this review was to highlight the advantages of using hemolymph for toxicity assays of various substances, including heavy metals, micro- and nano-plastics, pesticides, hydrocarbons, and oil spills. A literature search was conducted for this purpose using the most common and most often used databases, with a focus on the most recent and relevant studies. Bivalve mollusks, crustaceans, and gastropods were chosen for this investigation. This review found a growing number of studies choosing to use hemolymph as the standard methodology for toxicology assays, confirming their qualities as reliable tools.

The rainbow trout ( Oncorhynchus mykiss ) is one of the most commercially sought-after freshwater fish species and one of the most farmed in the world. On the other hand, aquaculture breeding frequently results in outbreaks of infectious diseases and pests, and compromises the production and welfare of fish. Arthrospira platensis (known as "Spirulina") has been used as a supplement in diets to enhance fish welfare in recent years because of its beneficial properties. This study aimed to assess the possible protective effects of Arthrospira platensis on rainbow trout specimens exposed to three different doses of the toxicant CdCl 2 . The experiment was carried out using five experimental treatments of 40 individuals each: control group; group II (0.2 mg CdCl 2 per kg of commercial fish feed); group III (0.2 mg Kg -1 of CdCl 2 plus 2.5 g per kg of A. platensis ); group IV (0.2 mg Kg -1 of CdCl 2 plus 5 g per kg of A. platensis ); group V (0.2 mg Kg -1 of CdCl 2 plus 10 g per kg of A. platensis ). During the experiment, dietary supplementation of A. platensis normalized all serum and blood parameters altered by the presence of CdCl 2 . A. platensis also had a protective effect on markers of oxidative stress.