| STATE COLLEGE,
Pa. (AP) FEBRUARY 04, 2000
— Giant worms living 1,700 feet below the surface of the Gulf of Mexico
have been found to be up to 250 years old — a record for creatures
without a backbone, scientists say.
Researchers from Penn State
University reported their findings in Thursday's issue of the journal
Nature.
The tube worms, whose
scientific name is Lamellibrachia, do not eat; they survive by absorbing
energy from chemicals that seep up through cracks in the sea floor.
The grow to lengths of 10
feet or more. That's not a record for worms. That distinction goes to a
tapeworm that lives in the intestines of whales.
This species is a fairly new
discovery. Scientists learned about it in the 1980s. The worms live in
clusters of millions, covering acres of ocean floor. Each worm is
protected by a thin, flexible, shell-like tube.
Some tortoises live even
longer. And marine biologist Charles Fisher said colonies of coral live
for centuries. But Lamellibrachia hold the age record for a single
invertebrate organism, he said.
Finding out the age of a
giant sea worm is a bit more complex than counting the rings of a tree.
Fisher and his colleagues rode a submarine to the bottom of the gulf,
where they used robotic arms to mark the ends of the tubes. Three months
later, they returned and measured how much the worms had grown. They kept
returning and measuring every few months for four years.
Once they had that data,
they were able to calculate how long it would have taken for the worms to
grow to their existing lengths.
What's the secret to this
longevity?
One hypothesis is that the
Lamellibrachia worms live in an environment where they are less likely to
get bruised, broken or run out of the energy they absorb. |