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Who would keep a collection of parasites?
Believe it or not, the United States government has been collecting them. And it's been doing it for a hundred years. The collection recently was acquired by the Smithsonian. It now numbers more than 20 million parasites. We keep parasites because they are a priority for research related to our well-being.
Parasites cause many diseases. Endoparasites can live inside your body. They include flatworms such as tapeworms or flukes. They may also include tiny animals of various types that can cause infections.
Even parasites that live on the surface of your body may cause infections. These are called ectoparasites. They give rides to other organisms. For instance, ticks give rides to Lyme disease bacteria. The bacteria cause as many as 25,000 infections per year. That is in the U.S. alone.
Ironically, parasites are also used for medical treatments. Leeches have natural anticoagulants in their spit. Because of this, they can keep blood flowing into reattached body parts that have been severed in accidents.
The importance of parasites goes way beyond their roles in disease. Research on parasites has been led by medical concerns. But parasites are also players to be reckoned with in the ecosystems we depend on. Recent studies along the California coast and elsewhere have revealed that the biomass (weight) of all the parasites in an ecosystem may be higher than the biomass of all the top predators. Parasites tend to be small. But there are lots and lots of them around!
By definition, a parasite lives in or on a "host." That could be a plant. It also could be a mammal like a human. Or it could be other animals like crabs. Parasites take resources from their hosts. But that don't give anything back. They usually don't kill their hosts. Like bad house guests, they may affect how their hosts behave. The close linkage they have with hosts makes parasites relevant for how entire ecosystems function and respond to change. Parasites are too prevalent to be ignored.
Learn about how scientists use museum collections to study the many associations between parasites and their hosts. Watch the live "Smithsonian Science How" webcast. It airs on Thursday, May 19, 2016 at 11 a.m. and 2 p.m. EDT.
The webcast is titled, "Living Together: Parasites and Hosts." It can be seen on the Q?rius website. Parasitologist Dr. Anna Phillips will discuss and answer questions live from the National Museum of Natural History. Get teaching resources to use with the webcast.