noun · a parasitic trematode flatworm, often referred to in specific names like the liver fluke

肝蛭常寄生在牛、羊等家畜的胆管内。

noun · an annelid worm belonging to the class Hirudinea, often found in freshwater and known for its bloodsucking habits

蛭类通过吸盘附着在宿主身上吸食血液。