THE XERCES SOCIETY FOR INVERTEBRATE CONSERVATION

Aquatic Invertebrates in Pacific Northwest Freshwater Wetlands
An Identification Guide and Educational Resource

Erpobdellidae are similar to Hirudinidae (the blood-sucking leeches). They have 0, 3 or 4 pairs of eyes aligned side-to-side whereas the Hirudinidae have 5 arranged in an arch. Both families are very good swimmers, while the other two leech families (Glossiphonidae, Piscicolidae) are not.

Erpobdellids generally have different feeding strategies from the bloodsucking Hirudinidae. Most are scavengers or predators on invertebrates, but a few will ingest the blood of animals. They lack jaws adapted for making incisions, however, so they usually won't take a blood meal unless their host is already bleeding.