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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, as well as tiny animals of various types. These can cause infections. Even parasites that live on the surface of your body (ectoparasites) may cause infections. They give rides to other organisms. Ticks give rides to Lyme disease bacteria. The bacteria cause as many as 25,000 infections per year in the U.S. alone.
Ironically, parasites are also used for medical treatments. Thanks to natural anticoagulants in their spit, leeches 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. While parasites tend to be small, there are lots and lots of them around!
By definition, a parasite lives in or on a "host." That could be a plant, a mammal like a human, or other animals like crabs. Parasites take resources from their hosts without giving 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 on Thursday, May 19, 2016. It is titled, "Living Together: Parasites and Hosts" (airs at 11 a.m. and 2 p.m. EDT 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.
CRITICAL THINKING QUESTION
How can tiny parasites outweigh predators?
Write your answers in the comments section below