To study the ecotoxicological effects of polystyrene microplastics (PS‐MPs) on C. quadricarinatus , the survival rate, histological structure of the hepatopancreas, composition and diversity of the gut microbiota, and metabolic response under PS‐MPs exposure condition were investigated. The experimental groups consisted of Group 1 (control group), Group 2 (10 mg/L PS‐MPs exposure group), Group 3 (50 mg/L PS‐MPs exposure group), and Group 4 (100 mg/L PS‐MPs exposure group). The study findings revealed no mortality in C. quadricarinatus in any of the treatment groups, except for the slow response of C. quadricarinatus only under 100 mg/L PS‐MPs exposure condition. Moreover, Group 3 and Group 4 showed damage to the hepatopancreatic tissues and deformations of the hepatic tubules and hepatopancreatic cells, resulting in increases in the volume of B cells and their internal transport vesicles. Further, increased particulate matter was observed in the transport vesicles, particularly in Group 4. Furthermore, 100 mg/L PS‐MPs exposure caused an increase in the abundance of Fusobacteria, Vibrio , and other bacteria, whereas the abundance of Firmicutes, Bacteroidota, and Candidatus Bacilloplasma decreased in the intestine. In addition, the Shannon and Simpson indices of Group 4 were significantly higher than those of Group 1. Significant metabolic differences under 100 mg/L PS‐MPs exposure condition, with differential metabolites mainly enriched in amino acid metabolic pathways such as taurine and histamine metabolism. In addition, it was enriched in fatty acid metabolism pathways, such as arachidonate metabolism, as well as other pathways, including uridine diphosphate glucose metabolism. In summary, exposure to 100 mg/L PS‐MPs caused histological damage to the hepatopancreas, alterations in the gut microbiota composition and diversity, and changes in the metabolomics of C. quadricarinatus .
Haiheng et al. (Thu,) studied this question.