Hirudo Medicinalis

Hirudo medicinalis, the European medicinal leech, is one of several leech species historically used as medicinal leeches, in the family Hirudinidae. Mature adults reach up to 20 centimeters in length, colored green, brown, or greenish-brown, with two suckers and tripartite saw-like jaws bearing about 100 sharp edges, and can consume up to ten times their own body weight in a single feeding. It prefers muddy freshwater pools and weedy ditches in temperate climates, ranging across Europe into Asia as far as Kazakhstan and Uzbekistan; nineteenth century over-harvesting sharply reduced its populations, and it is now classified Near Threatened by the IUCN and protected under CITES Appendix II, while remaining in medical use for reconstructive surgery and other therapies.