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185

Mark Siddall

OLogy Series
ologist
card
185

Mark Siddall

OLogy Series
ologist

It's no wonder that most people aren't crazy about leeches. These dark, slimy worms survive by sucking blood from other animals, or "hosts" -- including humans. But Dr. Mark Siddall thinks leeches are the most beautiful creatures on the planet. He studies how leeches live, move from host to host, how they affect biodiversity -- the variety of Earth's life -- and he works to protect them from extinction.

Leeches detect potential hosts:

by sensing vibrations

with sensitive eyes

both A and B

Are you right?

Correct!

When Mark is in the field, he hopes that his presence is detected by leeches living close by. Mark enjoys being the host for bloodthirsty leeches. It makes collecting easy!

Leeches are parasites, organisms that live in, or on, other organisms called:

hosts

entrees

appetizers

Are you right?

Correct!

Parasites live on the bodies of other organisms called hosts. Humans are hosts to parasites like mosquitoes and ticks.

Mark Siddall, Invertebrate zoologist

It was like unwrapping a Christmas present!

--Dr. Mark Siddall, on finding himself covered with leeches while working in Madagascar

To find a good collection of leeches, Mark must travel to the Amazon rain forest.

Fact
or
Fiction
?

Fiction

There are more leeches to be found in the forests, lakes, and rivers of Michigan than in the Amazon. Mark says Michigan is one of the best places in the world to search for leeches!

All leeches are harmful to humans.

Fact
or
Fiction
?

Fiction

In fact, leeches have been used for medicinal purposes since medieval times. Even today, some species are used to promote blood flow after certain kinds of surgery.

Mark Siddall
Date of Birth: November 22, 1966
Hometown: Georgetown, Ontario, Canada
Position: curator, Division of Invertebrate Zoology, American Museum of Natural History
Education: B.S. (1989), M.S. (1991), Ph.D. (1994), University of Toronto
Field of interest: leeches and all kinds of parasites

Image credits: courtesy of AMNH, Mark Siddall; Mark Siddall: courtesy of AMNH.