Leeches are segmented worms that belong to the phylum
Annelida and comprise the
subclass Hirudinea. Like the
oligochaetes, such as
earthworms, leeches share a
clitellum and are
hermaphrodites. Nevertheless, they differ from the oligochaetes in significant ways. For example, leeches do not have bristles and the external segmentation of their bodies does not correspond with the internal segmentation of their organs. Their bodies are much more solid as the spaces in their
coelom are dense with connective tissues. They also have two suckers, one at each end.