Leech - Hirudo medicinalis
Out of all the leeches Hirudo medicinalis is the most studied. The Hirudo medicinalis has two suckers and three jaws. This leech is a hermaphrodite and feeds on mammal blood. Although leech is associated with medicine (look at the name), they can be very dangerous. The digestive system for this bloodsucker has four main parts. The mouth opens with three crescent moons, used to make incisions. The pharynx is very muscular so that it can suck blood. The stomach has eleven gastric caeca, each with a valve, so that it can hold the victims blood for extends amounts of time. Finally, the intestine is a digestive tract that ends with the anus.