Oriental lung flukes (Paragonimus westermani) are a species of flatworms that are parasitic and can infect almost every organism on the planet. They range in size from five millimeters to 100 millimeters. The Oriental blood fluke develops in the egg, larval, and mature stages. They are in the Platyhelminthes class of Trematoda. They are mostly found in China, Korea, the Philippines, and Japan. They have a very primitive muscular system. The body of a fluke is covered by cilia that helps it move from side to side. It also has two layers of rigid muscles that protect it from predators and natural/artificial disasters. Their digestive cavity is an opening that is both their mouth and anus. They also have two nerves that start at their brain and run down the length of the body. They have both male and female reproductive organs, making them hermaphroditic. Lung flukes latch onto an animal's lungs and suck the fluid, causing the animal to die a slow and painful death from suffocation and increased neck pressure.