[1] These are small, flat leeches which do not feed on blood.

[2] Several species in this genus are used as model organisms in the study of developmental biology.

[1] It has been difficult to define species in this genus without DNA analysis.

Like other leeches in this family, some Helobdella species are polymorphic, coming in different colors and patterns.

[3] Species include:[2] Media related to Helobdella at Wikimedia Commons