1998, University of Delaware marine biologist Craig Cary
and his colleagues made international headlines when they determined that
the Pompeii worm, which lives at hydrothermal vents, is the
most heat-tolerant animal on Earth, able to survive a bath as hot as 176°F.
While some bacteria thrive at higher temperatures, the Pompeii worm ranks as the most heat-tolerant among complex life forms. The former record holder was the Sahara Desert ant, at 131°F.
Discovered in the early 1980s by French scientists, the Pompeii worm (Alvinella
pompejana) is about 4 inches long with tentacle-like, scarlet gills on its head. A gray "fleece" of bacteria covers the worm's back.
worm gets its name from the Roman city of Pompeii, which was destroyed during an eruption of Mount Vesuvius in 79 A.D. The Alvinella in the worm's scientific name stems from the submersible Alvin.
Pompeii worm makes paper-like tube colonies attached to hydrothermal
vent chimneys," says Dr. Cary. "While the very
hottest water shoots out the top of the chimneys, these structures
are so porous that hot water also seeps out the chimney sides
and through the worm's tube home."
The worm also displays a remarkably broad temperature gradient along its "hairy" body. By
inserting a temperature probe called "the Mosquito," from
the submersible Alvin into the worm's tube, Dr.
Cary found that the worm's rear end sits in water as hot
as 176°F, while its gilll-covered head, which often pokes
out of the worm's tube home, rests in much cooler water,
only about 72°F.
the Extreme 2004 expedition, Dr. Cary and his team from the
University of Delaware College of Marine Studies and Dr.
Alison Murray and her research group from the Desert Research Institute in Reno, Nevada, will be working
together to learn more about the Pompeii worm's incredible
heat tolerance by studying the bacteria that live right on
gray fleece, or "hair," that you see on the worm's
back is actually bacteria," Dr.
Cary notes. "Tiny
glands in the worm's skin secrete a mucous that the bacteria
appear to live and feed on."
"We're working to apply new genomics technologies to learn how these bacteria deal with the hydrothermal vent environment they inhabit in association with the worm," Dr. Murray adds.
Using tools borrowed from the Human Genome Project, such as DNA sequencers, the scientists will be working to access all the genetic information tied up in the bacteria -- their DNA code, or "road map of life," as Dr. Murray refers to it.
just as a road map has many more routes than are necesary
for getting from one destination to another, a microorganism's
genome can code for many, many pathways for carrying out
its daily requirements," she explains. "The route that's
actually taken on that road map represents the genes that
are 'expressed,' or 'turned on,' at any given times. That's
what we're looking for."
"Dr. Murray says this information will help address key questions about the sources of energy and food the bacteria use. The gene expression profile also can reveal other intriguing information, such as the genes involved in heat tolerance, metal detoxification, and cell-to-cell communication.
Pompeii worm and its bacteria are of interest to industry,
as well as the scientific community, because they may yield
a variety of products and applications, from new pharmaceuticals
to enzymes capable in operating in hot, corrosive, high-pressure
environments. Such enzymes can help dislodge oil inside wells,
convert cornstarch to sugar, process food and drugs, and
support a number of other industrial processes by speeding
up chemical reactions.