A realistic combined exposure scenario: effect of microplastics and atrazine on Piaractus mesopotamicus.

Microplastics, considered emerging environmental contaminants resulting from plastic degradation, are discovered in diverse aquatic ecosystems and can be unintentionally ingested by fish. Therefore, it is essential to characterize their interaction with other contaminants, such as agrochemicals, in aquatic environments. This study aimed to assess histological, enzymatic, and genotoxic biomarkers in juvenile pacú (Piaractus mesopotamicus) exposed to polyethylene (PE) microplastic particles and the herbicide atrazine, individually or combined, for 15 days.

Ecotoxicological Characterization of Lithium as a "Timebomb" in Aquatic Systems: Tadpoles of the South American Toad (Hensel, 1867) as Model Organisms.

The aim of this study was to evaluate the acute lethality and chronic sublethal effects of lithium (Li) on tadpoles as model organisms. First a 96 h toxicity assay was performed by exposing tadpoles to Li concentrations from 44.08 to 412.

Water and sediment quality of an agro-industrial area through different approaches: Physicochemical parameters and ecotoxicity with amphibians.

Amphibians are subject to several stressors in the aquatic and terrestrial environments, and human activities have profoundly impacted this vertebrate group. The aim of the present study was to analyze physicochemical parameters, metals and pesticide residues, and the toxicity of water and sediment samples from an environment with high agricultural activity (S1: Salto stream; S2: drainage channel downstream from S1) by means of bioassays using Rhinella arenarum (Amphibia: Anura) larvae. Metals and pesticides were analyzed in water and sediment samples by fluorescence spectrometer of X-ray by total reflection and ultra-high-performance liquid chromatography-MS/MS, respectively.

Sublethal Biochemical Effects of Polyethylene Microplastics and TBBPA in Experimentally Exposed Freshwater Shrimp .

The biochemical effects of sublethal exposure to polyethylene microplastics (PEM) of 40-48 µm particle size and the flame retardant tetrabromobisphenol A (TBBPA), a plastic additive, on the freshwater shrimp were assessed. Here, we postulate that the use of enzyme and thyroid hormones as biomarkers contributes to the knowledge of the effects of microplastics and plastic additives on freshwater crustaceans. To address this, we evaluated the activities of acetylcholinesterase (AChE), glutathione S-transferase (GST), and carboxilesterase (CbE, using 1-naphthyl acetate (NA) as substrate) and levels of the thyroid hormones thyroxine (T4) and triiodothyronine (T3) after shrimp were exposed (for 96 h) to these xenobiotics at environmentally realistic concentrations.

Cocktails of pesticide residues in Prochilodus lineatus fish of the Salado River (South America): First record of high concentrations of polar herbicides.

Muscle and viscera (gills-liver) of the fish Prochilodus lineatus were obtained from four sites of lower course of Salado river and one site at Santa Fe river near to its confluence with Salado river from Santa Fe (Argentina) between December 2021 and February 2022. Sediment samples were also obtained from the same sites. All samples were analyzed for pesticide residues following the QuEChERS method to quantify 136 compounds by UHPLC-ESI-MS/MS and GC-EI-MS/MS.

Impact of soil from monoculture pine plantations on two anuran species from the Atlantic Forest: Odontophrynus reigi and Leptodactylus luctator.

Monoculture tree plantations reduces landscape heterogeneity and the number and diversity of habitats available for species. Physical-chemical changes in soil may affect the ponds where tadpoles develop. This work aimed to study the effect on tadpoles of two species of frogs, Leptodactylus luctator (Ll) and Odontophrynus reigi (Or) exposed to soils from a pine plantation (PP), which were compared to tadpoles exposed to soils from Atlantic Forest, the native forest (NF).

Effect of glyphosate and ciprofloxacin exposure on enteric bacteria of tadpoles.

The high load of agrochemicals and antibiotics present in agricultural aquatic environments represents a risk for wildlife. Since enteric bacteria, which play a key role in the physiological functioning of their hosts, are sensitive to a wide variety of pollutants, their study allows to evaluate the health of organisms. This study aimed to evaluate the effects of commercial formulations of a glyphosate-based herbicide (GBH) and the antibiotic ciprofloxacin (CIP), individually and in mixture, on the bacterial diversity of the intestinal content of common toad (Rhinella arenarum) tadpoles.

Environmental quality and ecotoxicity of sediments from the lower Salado River basin (Santa Fe, Argentina) on amphibian larvae.

The lower Salado River basin receive agricultural, industrial and domestic waste water. So, the aim was to evaluate the quality of three sampling sites that belong to the Salado River basin (S1: Cululú stream; S2: Salado River, at Esperanza City, S3: Salado River at Santo Tomé City) based on physicochemical parameters, metals and pesticides analyses and ecotoxicity on Rhinella arenarum larvae. R.

Comparative assessment of individual and mixture chronic toxicity of glyphosate and glufosinate ammonium on amphibian tadpoles: A multibiomarker approach.

The aim of the present study was to assess the ecotoxicity of glyphosate and glufosinate ammonium mixtures on amphibian tadpoles and the potential impact of mixture in aquatic ecosystems health. The bonding properties of the mixture based on computational chemistry and an experimental bioassay on morphology, DNA damage and biochemical biomarkers on tadpoles of the common toad Rhinella arenarum were studied. The results of the density functional theory analysis showed trends of the pesticides clustering to form exothermic mixtures, suggesting the likelihood of hot-spots of pesticides in real aquatic systems.

The integrated biomarker response in three anuran species larvae at sublethal concentrations of cypermethrin, chlorpyrifos, glyphosate, and glufosinate-ammonium.

The aim of the present study was to evaluate the response in larvae of the anuran species , and exposed to glyphosate (GLY, 2.5 mg L), cypermethrin (CYP, 0.013 mg L), chlorpyrifos (CP, 0.

Bioaccumulation of abacavir and efavirenz in Rhinella arenarum tadpoles after exposure to environmentally relevant concentrations.

Antiretrovirals are pharmaceuticals used in the treatment of the human immunodeficiency virus; they are contaminants of emerging concern that have received considerable attention in recent decades due to their potential negative environmental effects. Data on the bioaccumulation and possible environmental risks posed by these drugs to aquatic organisms are very scarce. Therefore, the aim of this study was to evaluate the bioaccumulation of abacavir and efavirenz in Rhinella arenarum tadpoles subjected to acute static toxicity tests (96 h) at environmentally relevant concentrations.

Anuran heart development and critical developmental periods: A comparative analysis of three neotropical anuran species.

The heart begins to form early during vertebrate development and is the first functional organ of the embryo. This study aimed to describe and compare the heart development in three Neotropical anuran species, Physalaemus albonotatus, Elachistocleis bicolor, and Scinax nasicus. Different Gosner Stages (GS) of embryos (GS 18-20) and premetamorphic (GS 21-25), prometamorphic (GS 26-41), and metamorphic (GS 42-46) tadpoles were analyzed using stereoscopic microscopy and Scanning Electronic Microscopy.

Impact of dietary lipid level on esterase enzyme activities in the non-target freshwater shrimp Macrobrachium borellii exposed to chlorpyrifos.

This study increases our understanding of how diet-driven phenotypic plasticity can help non-target aquatic invertebrates deal with chlorpyrifos (CPO) exposure. A bioassay was performed over 6 days with the freshwater shrimp Macrobrachium borellii. Experimental treatments included CPO-treated shrimps (10 μg L) were fed with (i) a lipid-rich diet, (ii) a lipid-medium diet, or (iii) a lipid-poor diet.

Morphological and histological abnormalities of the neotropical toad, (Anura: Bufonidae) larvae exposed to dexamethasone.

Dexamethasone (DEX) is a glucocorticoid highly effective as an anti-inflammatory, immunosuppressant and decongestant drug. In the present study, a preliminary acute toxicity test was assayed in order to determinate DEX median-lethal, lowest-observed-effect and the no-observed-effect concentrations (LC, LOEC and NOEC, respectively) on the common toad embryos (). Also, morphological and histological abnormalities from five body larval regions, liver melanomacrophages (MM) and glutathione S-transferase (GST) activity were evaluated in the toad larvae to characterize the chronic sublethal effects of DEX (1-1,000 µg L).

Toxicity assessment at different experimental scenarios with glyphosate, chlorpyrifos and antibiotics in Rhinella arenarum (Anura: Bufonidae) tadpoles.

The presence of pesticides as well as that of several antibiotics provided at a great scale to poultry, cattle, and swine in aquatic environments within agroecosystems is a matter of growing concern. The objective of the present study was to characterize the sublethal effects of four environmental toxic compounds at two experimental pollution scenarios on the morphology, development and thyroid (T4), acetylcholinesterase (AChE) and glutathione S-transferase (GST) levels in Rhinella arenarum tadpoles. The first experimental pollution scenario aimed to evaluate the individual and mixed toxicity (50:50% v/v) of a glyphosate-based herbicide (GBH) and the antibiotic ciprofloxacin (CIP) on earlier developmental stages.

Bioaccumulation and glutathione S-transferase activity on Rhinella arenarum tadpoles after short-term exposure to antiretrovirals.

The aim of the present study was to investigate the bioaccumulation and toxicological effects of four antiretrovirals (lamivudine, stavudine, zidovudine and nevirapine) on Rhinella arenarum tadpoles, after short-term (48 h) exposure to these drugs at sublethal concentrations. The analytical procedure involved a simple extraction method followed by ultra-high performance liquid chromatography with diode array detection and chemometric analysis for data processing. Under the conditions studied, the analytes investigated, particularly nevirapine, showed possible bioaccumulation in tadpoles.

Comparative Toxicity of Two Different Dimethoate Formulations in the Common Toad (Rhinella arenarum) Tadpoles.

Dimethoate (D) are among the most commonly used organophosphates insecticides in the world. To evaluate the toxicity of two D formulations were selected as test organisms tadpoles of Rhinella arenarum. This toad species has an extensive neotropical distribution and is easy to handle and acclimate to laboratory conditions.

First evaluation of novel potential synergistic effects of glyphosate and arsenic mixture on (Anura: Bufonidae) tadpoles.

The toxicity of glyphosate-based herbicide (GBH) and arsenite (As(III)) as individual toxicants and in mixture (50:50 v/v, GBH-As(III)) was determined in tadpoles during acute (48 h) and chronic assays (22 days). In both types of assays, the levels of enzymatic activity [Acetylcholinesterase (AChE), Carboxylesterase (CbE), and Glutathione S-transferase (GST)] and the levels of thyroid hormones (triiodothyronine; T3 and thyroxine; T4) were examined. Additionally, the mitotic index (MI) of red blood cells (RBCs) and DNA damage index were calculated for the chronic assay.

Biotoxicity of diclofenac on two larval amphibians: Assessment of development, growth, cardiac function and rhythm, behavior and antioxidant system.

The non-steroidal anti-inflammatory drug diclofenac (DCF) threatens the health of aquatic animals and ecosystems. In the present study, different biological endpoints (mortality, development and growth, abnormalities, cardiotoxicity, neurotoxicity and antioxidant system) were used to characterize the acute and chronic effects of DCF (at concentrations ranging between 125 and 4000 μg L) on two amphibian species from Argentina (Trachycephalus typhonius and Physalaemus albonotatus). Results showed that the larval developmental, growth rates, and body condition of DCF-exposed individuals of both species were significantly reduced.

Insecticide pyriproxyfen (Dragón) damage biotransformation, thyroid hormones, heart rate, and swimming performance of Odontophrynus americanus tadpoles.

Odontoprynus americanus tadpoles were used to determine the safety concentration of pyriproxyfen (PPF) insecticide by acute and sublethal toxicity tests (nominal range tested 0.01 to 10 [± 15%] PPF mg/L). Median lethal concentration (LC) and no, and lowest-observed-effect concentrations (NOEC and LOEC, respectively) were calculated.