Hirudinea

Hirudinea is a class of segmented worms commonly known as leeches. They are soft-bodied invertebrates that typically inhabit freshwater, marine, and moist terrestrial environments. Leeches have a flattened, elongated body divided into multiple segments, often with suckers at both ends. Many species are hematophagous, meaning they feed on the blood of vertebrates, using specialized mouthparts to cut and suck blood, which can aid in medical treatments like draining excess blood or fluid. Others are scavengers or predators. Overall, Hirudinea play important roles in ecosystems, contributing to nutrient cycling and controlling populations of other invertebrates.