January 22, 2008

Bizarre Amphibians Found Living on the Edge

Blind salamanders, legless amphibians with tentacles on their heads and
ghost frogs whose favorite haunt is a human burial ground are just a
few of the world's weirdest and most endangered creatures.

The Zoological Society of London announced this week these are among the 10 most unusual and threatened amphibian species,
as part of the EDGE Amphibians conservation and fundraising initiative.
Amphibians that made the list are deemed by the society to be the most
evolutionarily distinct and globally endangered, aka EDGE species. They
have few close relatives in the tree of life and are genetically
unique, along with being on the verge of extinction.

"These animals may not be cute and cuddly, but hopefully their weird
looks and bizarre behaviors will inspire people to support their
conservation," said Helen Meredith, EDGE Amphibians conservationist in

Species that are evolutionarily distinct are one of a kind, said Arne Mooers of Simon Fraser University in Canada.

"We can't afford to lose these ones, because they are so different from
everything else," said Mooers, who works with scientists as part of the
EDGE of Existence program. "If we lose these, then we lose a big chunk
of the total variation," he said, referring to overall biodiversity.

Peculiar pin-ups

The alien-looking amphibians come in all sizes, from the Chinese giant salamander to the Gardiner's Seychelles frog that's smaller than a thumb nail, and in all colors, including the Malagasy rainbow frog and the pale Olm salamander that dwells in limestone caves.

The Chinese giant salamander, with a nose-to-rump length of up to
nearly six feet (1.8 meters), tops the list as the highest conservation
priority, Meredith said. One threat has been hunting. Locals and others
use hooks to capture the burrowing salamanders for their skin,
considered a delicacy by some.

Another chart-topper is the purple frog, Nasikabatrachus sahyadrensis.
The purple-pigmented frog wasn't discovered until 2003, because it
stays hidden beneath about 13 feet (four meters) of earth for most of
the year, feeding on termites.

Some peculiar parents on the top-10 list include the Betic midwife toad
and the Chile Darwin's frog, both of which rely on the male as
caretaker. For instance, the male Darwin's frog keeps the babies safe
by swallowing them.

"When the tadpoles are developing enough and wriggling in the egg, the male gulps them down into his vocal sac," Meredith told LiveScience.

Amphibian alarms

Not only do these odd amphibians need protection, but they could shed
light on the broader extent of environmental degradation. Some
scientists refer to amphibians as canaries in the coal mine for the
state of the environment.

"There are lots of things that make amphibians brilliant indicator
species," Meredith said. "They are often found in quite small ranges
and they don't have the ability to migrate long distances, most of

If their patch of land becomes degraded in some way, the amphibians
can't really go anywhere else, Meredith explained, so they just stay
put and die. "If the amphibian communities are dying, it's basically
saying that place right there is no longer a healthy environment," she

Amphibians also have very sensitive skin, so toxins in the environment
readily take a toll on them. "A lot of them breathe through their skin,
sometimes to the exclusion of even using their lungs," Meredith said.

A group of salamander species living in southern Mexico, which took the
number-6 spot on the list, isn't even equipped with lungs. Instead
these salamanders breathe through their skin and mouth lining.