Parasites of Humans
There are many types of tapeworms that are known to be on earth, however there are three main tapeworms are: Tainiarhynchus saginatus, Taenia solium, and Diphyllobothrium latum.
The Taeniarhynchus saginatus otherwise known as the "Beef Tapeworm". Adults live in the small intestine and can reach a length of 25 m. When an egg develops inside of the host, it forms a six hooked larva called the onchosphere. As cattle graze in pastures contaminated with human feces they ingest onchosphere. When a human ingests the infected cow meat (Usually raw and Improperly cooked).
The Taenia solium has a similar life cycle of the beef tapeworm, except its intermediate host is the pig. When these larvae hatch, they move through the intestinal wall enter the bloodstream, and are distributed throughout the body, where they eventually encyst in the human tissue cystcerci, the disease results is called cysticercosis and can be fatal if in the brain.
Diphyllobothrium latum also know as the the broadfish tapeworm. An adult worm may attain a length of 10 m also they can shed up to a million eggs a day. When eggs are deposited into freshwater they hatch,and the coracidia emerges, they swim until small crustaceans called copepods ingest them. When fishes ingest the copepods the larva burrows into the muscle of the fish to develope into the plerocercoid larva. When humans ingest the infected fish the plerocercoid attaches to the small intestine and develops into an adult worm.