Pesticides can induce changes in behavior and reduce the survival chance of aquatic organisms. In this study, the toxic effects of glyphosate suspension (Glyphosate Aria 41% SL, Tehran Iran) on behavior and tissues of common carp (Cyprinus carpio) were assessed. For this purpose, a 96 h LC₅₀ of glyphosate suspension (68.788 mL·L⁻¹) was used in the toxicity test. All individuals were divided into control and treatment groups with four replicates. Exposure operations were performed under two conditions: increasing concentration of suspension from 0 to 68.788 mL·L⁻¹; then, decreasing to the first level. The swimming pattern was recorded by digital cameras during the test and tissue samples were collected at the end of the test. There were significant differences between the swimming pattern of treated individuals and control ones during both steps. The sublethal concentration of glyphosate led to hypertrophy, hyperplasia and hyperemia in the gill of fish. However, changes were obvious only after sampling. The exposed fish also displayed clinical signs such as darkening of the skin and increasing movement of the operculum. Moreover, glyphosate suspension affected swimming patterns of fish suggest that the swimming behavior test can indicate the potential toxicity of environmental pollutants and be used as a noninvasive, useful method for managing environmental changes and assessing fish health conditions by video monitoring.

Nanoparticles (NPs) can display toxicological effects on aquatic organisms. This study investigates ecotoxicological effects of Ag-NPs on reproductive and blood parameters of adult common molly (Poecilia sphenops) and their larvae. During the LC50 96 h test, female fish were exposed to concentrations of 0, 5, 15, 25, 35, 45 and 60 mg L⁻¹ of Ag-NPs, while larvae were exposed to 0, 3, 5, 10 and 15 mg L⁻¹. Finally, we aim to evaluate the effects of 0, 5, 10 and 15 mg L⁻¹ of Ag-NPs on parturition time, reproductive success and hematological parameters of the mature fish exposed to sub-lethal concentration during a 62-day period. We also evaluated the survival rate of larvae. The results show a positive correlation between mortality rate and Ag-NP concentration. Values for LC50 96 h in adult fish and larvae were 26.85 mg L⁻¹ and 6.22 mg L⁻¹, respectively. A lack of parturition and reproductive success were seen in fish that underwent chronic exposure to Ag-NPs (15 mg L⁻¹). The results show that RBC, WBC and hematocrit were significantly decreased in fish exposed to Ag-NPs. In addition, the serum concentrations of total protein, albumin, cholesterol and triglycerides were significantly increased in fish submitted to Ag-NPs (concentrations of 5–15). In conclusion, submitting a fish to higher concentration than 10 mg L⁻¹ has adverse effects on reproductive system and blood parameters.

The increasing use of nano-based products raises concerns regarding potential risks related to their manufacturing, transportation, waste disposal, and management operations. We used the riverine carp, Capoeta capoeta, as an aquatic animal model to demonstrate the acute toxicity of silver nanoparticles (Ag-NPs). This study focuses on acute toxicity first, and then integrates the findings through histopathology, hematological, and biochemical testing of lethal and sub-lethal Ag-NPs exposures. Red blood corpuscles (RBC), white blood corpuscles (WBC), hematocrit, and total serum glucose levels were significantly lower in Ag-NPs-exposed fish than in control fish. Total serum protein, triglycerides, cholesterol, and albumin were all significantly greater in exposed fish. This research focused on the impacts of Ag-NPs on gills and liver tissue, and it was found that the level of injury escalated as the concentration of Ag NPs increased. Epithelial lifting of secondary lamellas (ELSL), epithelial hypertrophy (EH) of secondary lamellae (SL), leukocyte infiltration (LI), and bottom hyperplasia (BH) were all detected in Ag-NPs-exposed fish. In Ag-NPs-treated liver cross-sections of Capoeta capoeta, macrophage aggregates (MA), fatty liver (FL), sinusoid dilatation (SD), and necrosis (N) were identified. Ag-NPs dosages, according to biomarker representations, elicit stress-specific biochemical and physiological effects, compromising the general overall health status of aquatic animals. The gradients of toxic responses across exposure concentrations and portrayals of disrupted fish health with increasing silver nanoparticle exposure time indicate a reduced physiological ability for surviving in the wild.

The presence of pesticides and their potential toxic effects on fish can pose a threat to aquatic ecosystems and human health. The present study aimed to evaluate the effect of commercial formulations of glyphosate (Roundup) on the survival rate, hematological parameters, and tissues (gills and liver) of juvenile grass carp (Ctenopharyngodon idella). For these purposes, we exposed the fish to 0, 50, 100, and 150 mL L⁻¹ of Roundup for 96 hr. Results showed a significant correlation between the fish’s mortality rate and pesticide concentrations ( ); the LC₅₀ 96 hr of Roundup was 75.838 mL L⁻¹ in the present study. The concentrations above 50 mL L⁻¹ induced significant tissue lesions seen as lamellar aneurism, leukocyte infiltration, distal hyperplasia, cloudy swelling, macrophage aggregates, and necrosis in the gills and liver. We also reported a significant correlation between the severity of tissue damage and Roundup concentration. The hematocrit, hemoglobin, white, and red blood cell count significantly reduced after 96 hr of exposure to 100 and 150 mL L⁻¹. The opposite trend was reported for concentrations of glucose, albumin, cholesterol, total protein, and triglycerides. Finally, the fish exposed to 100 and 150 mL L⁻¹ of Roundup displayed some clinical signs, such as increasing operculum movement, darkening the skin, and swimming near the surface during the movement test. Overall, our results showed that concentrations of Roundup higher than 50 mL L⁻¹ can induce various toxic effects and significantly reduce the survival chance of juvenile grass carp. Roundup altered fish behavior, tissue functioning, and biochemical processes. In this study, we provided some basic knowledge about the effects of a glyphosate-based herbicide on aquatic organisms and possible environmental management.