HIRUDO belongs to the annulata gate, ZhiGang, jaw leech item, HIRUDO branch. ZhiGang including 4 item, namely thorn leech item, kisses the leech item, jaw leech item, swallows leech item, following main introduction jaw leech item.

     Jaw leech item (Ganthobdellidae) the animal not expandable lips, YanHou are fixed, in the oral cavity has 3 EBan. In vivo not genuine vascular system, substitutes by the blood body cavity system. The blood body cavity fluid is red, has Grape Shape the organization. The reproductive system quite is complex, usually has the copulation organ, in the egg cocoon has the protein nutrition embryo. All festival basically becomes by 5 links development. Aquatic or Lu Sheng. For example uses in to let blood the therapy, the elimination StasisBlood, surgical operation and so on severed limb replantation Hirudo nipponica as well as with Li Hirudo nipponica and so on; Widely is once used for in ancient India to let blood, avoids the cow leech which uses the surgical department scalpel:Poecilobdella javanica, P.similis, P.manil-lensis; Life in Warm is wet the mountainous area, waits for the passing host in the thick patch of grass or the bamboo grove, slurps the vertebrate blood Haemadipsa: Haemadipsa japonica, H.tianmushana, H.yanyuanensis; In our country pond, the rice paddy distributes the very universal Whitmania: W.pigra, smooth gold thread leech, high-pitched and fine gold thread leech.