Life Of Leeches

• Arhynchobdellida lack a proboscis and may or may not have jaws armed with teeth. Arhynchobellids are divided into two orders:
- Gnathobdela: In this order of "jawed" leeches, armed with teeth, is found the quintessential leech: the European medical (bloodsucking) leech, Hirudo medicinalis. It has a tripartite jaw filled with hundreds of tiny sharp teeth. The incision mark left on the skin by the European medical leech is an inverted Y inside a circle. Its North American counterpart is Macrobdela decora, a much less efficient medical leech. Within this order, the family Hirudidae is characterized by aquatic leeches and the family Haemadipsidae by terrestrial leeches. In the latter are Haemadipsa sylvestris, the Indian leech and Haemadipsa zeylanica (yamabiru), the Japanese mountain or land leech.
- Pharyngobdella: These so-called worm-leeches consist of freshwater or amphibious leeches that have lost the ability to penetrate a host's tissue and suck blood. They are carnivorous and equipped with a relatively large, toothless, mouth to ingest worms or insect larvae, which are swallowed whole.
The Pharyngobdella have six to eight pairs of eyes, as compared with five pairs in Gnathobdelliform leeches, and include three related families. The Erpobdellidae are some species from freshwater habitats.