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Acknowledgments
I researched this book by picking the brains of many scientists, either in person or via telephone lines and modems. Thanks go in particular to Larry Roberts, who read the entire manuscript. I salute all of these scientists as any parasite must salute its host. My thanks go to:
Greta Smith Aeby
Jonathan Baskin
Nancy Beckage
George Benz
Manuel Berdoy
Jeff Boettner
Daniel Brooks
Janine Caira
Dickson Despommiers
Andrew Dobson
Thomas Eickbush
Gerald Esch
Donald Feener
Michael Foley
Scott Gardner
Matthew Gilligan
Bryan Grenfell
Iah Harrison
Hans Herren
Eric Hoberg
Jens Høeg
Peter Hotez
Stephen Howard
Frank Howarth
Michael Huffman
Hillary Hurd
Todd Huspeni
Mark Huxham
John Janovy
Daniel Janzen
Aase Jesperson
Pieter Johnson
Martin Kavaliers
Christopher King
Jacob Koella
Stuart Krasnoff
Armand Kuris
Kevin Lafferty
Curtis Lively
Philip LoVerde
David Marcogliese
Scott Miller
Katherine Milton
Anders Møller
Janice Moore
Thomas Nutman
Jack O’Brien
Richard O’Grady
Norman Pace
Edward Pearce
Barbara Peckarsky
Kirk Phares
Stuart Pimm
Ramona Polvere
Mickey Richer
Larry Roberts
David Roos
Mark Siddall
Joseph Schall
Phillip Scott
Andreas Schmidt-Rhaesa
Biola Senok
Michael Strand
Michael Sukhdeo
Suzanne Sukhdeo
Richard Tinsley
John Thompson
Nelson Thompson
Mark Torchin
Joel Weinstock
Clinton White
Marlene Zuk
Also, thanks to David Berreby for some insights on history, Jonathan Weiner for making the worm connection, Grace Farrell for hosting the parasite movie marathon and otherwise tolerating a strange obsession, Eric Simonoff for recognizing fertile gruesomeness when he saw it, and my editor, Stephen Morrow, who, as ever, makes it all happen.
Photos
Malcolm Jones, Centre for Microscopy and Microanalysis, the University of Queensland
AFIP NEG. NO. 71-3163
Hookworms live inside 1.3 billion people. They use their powerful teeth to lacerate a patch of the intestinal wall (inset) and drink blood from the wound.
© Manfred Kage/Peter Arnold Inc.
Tapeworms, reaching up to sixty feet long, are the biggest parasites that live in humans.
Claire Healy, University of Connecticut
Courtesy of Kirsten Jensen, University of Connecticut
Daniel Brooks
Claire Healy
Courtesy of Kirsten Jensen
Darlyne Murawski
There are 5,000 known species of tapeworm that live in various animals, and probably many thousands more still await discovery. Each one has a head specially adapted for lodging itself in its host’s body.
AFIP NEG. NO. 218934-42
Schistosoma (also known as the blood fluke) infects more than 200 million people. Its eggs hatch in fresh water and the young parasite seeks out a snail.
Inside the snail, the parasite passes through several generations before producing a missile-shaped stage called a cercaria.
Ming Wong
The cercaria then penetrates human skin and becomes an adult that finally ends up in the veins of its human host.
Dickson Despommiers
Trichinella, the cause of trichinosis, is an exceptional parasite: an animal that lives like a virus. Its larvae penetrate individual muscle cells and coil up inside, taking control of the muscle’s DNA in order to make the cells a more comfortable home.
Lennart Nilsson/Albert Bbonniers Forlag AB
The single-celled parasite Plasmodium falciparum causes malaria. Here a new generation of the parasite bursts out of a red blood cell.
© Oliver Meckes, Science Source/Photo Researchers, inc.
Bottom left: Another single-celled parasite, Trypanosoma brucei, is the cause of sleeping sickness.
David Roos
Toxoplasma gondii (shown here nestled inside a host cell) is one of the most successful parasites on Earth: in some regions of the world, 90 percent of people carry it in their bodies.
Matthew Gilligan
Matthew Gilligan
Parasites often choose very particular—and peculiar—places to live. This crustacean invades a fish’s mouth, devours its tongue, and takes the tongue’s place. It then acts like a tongue; the fish can use it to grip and swallow prey.
George Benz, Southeast Aquatic Research Institute, and Jeff Braswell, Dupont
Another choosy parasite is the crustacean Ommatokoita elongata. It lives only in Greenland sharks, which roam underneath the Arctic ice. Moreover, Ommatokoita lives only in their eyes, anchoring itself in the eyes’ jelly with its specially adapted legs.
Photo by Marianne Alleyne and Nancy Beckage
Insects are masters at parasitizing other insects. Parasitic wasps lay their eggs inside caterpillars, and the larvae slowly devour their living hosts before crawling out and weaving cocoons.
Elke Buschbeck, Birgit Ehmer/Cornell University
The insect Xenos peckii makes non-parasitic paper wasps its host. When its eggs hatch, the female stays inside, devouring its hosts’ sex organs, while the male burrows out and flies to another wasp to find a mate. As an adult, the male has only a few hours to live; as a result, it has evolved remarkable eyes to help find a mate. It has 100 miniature eyes, each of which is equipped with its own retina, able to form a full image of its own.