Hirudo Medicinalis
The European Medical Leech is a member of the phylum Annelid and subclass Hirudinea. They were used medicinally to remove blood when blood was not circulating properly after a wound, as the blood could clot without any attempt being made to heal the wound. This would cause a permanent clot of blood that could be cured through leech therapy, as leeches use an anticoagulant known as hirudin to keep the wound open and allow fresh blood to run, even after the leech was removed.
On its anterior sucker, leeches have three teeth, or blades, which leave a Y-shaped mark after a bite. Behind these blades is the mouth of the leech, which leads into the leech's digestive system. The leech, however, has an organ, called the crop, that can contain the blood that it absorbed. This species of leech can store enough blood in the crop that it needs to feed only twice a year. The leech's crop is linked to its gizzard, which then leads into its intestines.
On its anterior sucker, leeches have three teeth, or blades, which leave a Y-shaped mark after a bite. Behind these blades is the mouth of the leech, which leads into the leech's digestive system. The leech, however, has an organ, called the crop, that can contain the blood that it absorbed. This species of leech can store enough blood in the crop that it needs to feed only twice a year. The leech's crop is linked to its gizzard, which then leads into its intestines.