GIANT SALAMANDERS REALLY EXIST?
May 22, 2011
By my calculation,
if all the salamanders Tom Luhring caught during his research project
for his master's degree from the University of Georgia were laid end to
end, they would be longer than three football fields. That has to be a
is now a doctoral student at the University of Missouri, conducted his
research at the Savannah River Ecology Laboratory in South Carolina on
a group of amphibians known as the giant salamanders. These secretive
creatures inhabit swamps and lowlands, spending their entire lives in
the mud and waters of places where few people ever go. His studies of
one species, the greater siren, have revealed more about their population
ecology, movement patterns and behavior than had ever been known before.
The species, which has been known to science for more than two centuries,
is one of the heaviest salamanders in the Western Hemisphere. Yet little
was known of certain aspects of its biology before Tom's research.
salamanders in North America are aquatic species that live in the East.
The greater siren reaches lengths of more than three feet. Another giant
salamander of the Southeast, the amphiuma, has a record length of almost
four feet. Like sirens, amphiumas are seldom seen by people despite their
large size. That their scientific name (Amphiuma) is used as their
common name in most places is indicative of their rarity, although they
are called lamper eels or Congo eels in some regions.
salamanders, the hellbender and the mudpuppy, or waterdog, also qualify
as giants, although neither gets as long as the biggest amphiumas and
sirens. The mudpuppy, reaching a length of a foot and a half, is primarily
a northern species, found in lakes, ponds and rivers. Hellbenders are
bulky creatures that can reach two and half feet long. They live in cold
mountain streams and rivers from Alabama to New York. The world's largest
salamander, from Japan, is closely related to the hellbender; it can be
more than five feet long.
amphiumas, despite their enormous size relative to other amphibians, have
minuscule legs with toes. An amphiuma more than a yard in length will
have legs less than an inch long and no thicker than a toothpick. Amphiumas
and sirens are short-legged, dark-colored, slippery creatures, but distinguishing
one from the other is easy: sirens have only two of the seemingly useless
legs, whereas amphiumas have four. In addition, sirens have external,
visible gills; amphiumas have an opening alongside the head that leads
to internal gills.
amphiumas are slimy animals that seldom leave the water; they would soon
dehydrate if left on dry ground. But both live in aquatic habitats that
can dry up completely during long-term droughts. What do great big water-dwelling
salamanders do then? First, as their lake home dries up, they burrow into
the remaining mud. Then they secrete a slimy body covering, which hardens
into a cocoon that can keep them moist for a few months to more than a
year. When the rains return and the cocoon is exposed to water, the siren
or amphiuma emerges to begin feeding on aquatic insects and other invertebrates
that have also survived the drought.
amphiumas kept in aquariums as pets have been known to live for decades,
but no one knows how long they can live in the wild. Their courtship and
mating behavior are also still a mystery, even for specimens kept in captivity.
Amphibian biologists are not sure how closely related sirens are to other
salamanders, and some even argue that sirens are not salamanders at all,
but some other type of amphibian.
giant salamanders bring to the fore two ecological insights. One, scientists
know relatively little about the biology of some of the largest animals
in our midst, which means we still have much to learn about the world
around us. Second is the realization that some of our local creatures
are as fascinating in their own way as any exotic species with a starring
role in a nature show.
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