The 5th International Conference on Advances in Civil and Ecological Engineering Research (ACEER 2023)

Abstract: The toxic effect of phoxim on crucian carp (carassius auratus) was investigated via Hematoxylin-Eosin staining (HE) combined with Scanning Electron Microscope (SEM) and Transmission Electron Microscope (TEM) observation. The results of morphology identified by HE staining, SEM and TEM demonstrated that certain concentration phoxim could induce pathological damage of liver (drug metabolism organ), gill- (respiratory organ) and brain (nervous system) in crucian carp at tissue and cell level at different degree. The morphology results was more and more clear and persuasive with the approach used becoming more and more advanced from HE staining to SEM then to TEM. The experimental setup included a blank control group and a phoxim exposure group with semi static poisoning method. The exposure concentration was set to two dosage groups: high dose (0.33mg/L) and low dose (0.083 mg/L) with exposure time of 40 days and 60 days, respectively. Under these conditions, the HE staining observation results, as well as the SEM and TEM observation results were listed below: Compared with the control group, the liver, gills, and brain of crucian carp were damaged from pathology and morphology under the action of phoxim. The appearance of liver of crucian carp damaged was a disordered arrangement of liver cells, with honeycomb like damage and cell rupture; The appearance of gill of crucian carp damaged was: large area of epithelial cells shedding and cell deformation; The appearance of brain of crucian carp damaged was: the neurons in the hippocampus were loose and disordered, the neuronal body was deformed, some cell nuclear membranes were broken, and the nucleus was dissolved. The degree of damage to various parts showed a dose-effect relationship and a time-dependent relationship. The damaged effects of phoxim on the liver, gills, and brain tissues of crucian carp may be one of the mechanisms underlying its toxic effects on crucian carp and it is necessary for further research.