Conservationists are putting out an all points bulletin for dozens of possibly extinct species of frogs, toads and salamanders, including the world's "Ten Most Wanted" amphibians.

The search, led by Conservation International and the IUCN Amphibian Specialist Group, is aimed at rediscovering as many as 40 species in 18 countries across Latin America, Africa and Asia. Conservation International characterizes it as the "first-ever coordinated effort" to find so many lost creatures.

The point of the exercise is not merely to build up somebody's collection of museum specimens, but to document the horrific decline of amphibian species and figure out what to do about it. It's thought that more than 30 percent of all amphibian species are threatened with extinction. In a before-and-after survey of a Panamanian national park, researchers found that nearly 40 percent of the amphibian species in one little area had disappeared between 2004 and 2008.

"Amphibians are particularly sensitive to changes in the environment, so they are often an indicator of damage that is being done to ecosystems," Conservation International's Robin Moore said today in a news release announcing the quest. "But this role as the global 'canary in a coal mine' means that the rapid and profound change to the global environment that has taken place over the last 50 years or so - in particular, climate change and habitat loss - has had a devastating impact on these incredible creatures."

A pathogenic fungus ranks as the deadliest threat to amphibians: The microscopic critters cause a disease called chytridiomycosis, which has wiped out whole species in the Americas. Some frogs have been airlifted to other habitats or relocated to zoo "arks," just to buy time while scientists figure out how to fight the fungus.

To call attention to the search, Conservation International and the IUCN (which issues an annual list of threatened and endangered species) came up with a top-ten list of amphibians they're looking for. The list is based on the scientific as well as aesthetic significance of the species. No. 1 on the list is Costa Rica's golden toad, which was apparently pushed into extinction within just a year or two in the late 1980s. It's not known exactly what caused the die-off, but researchers assume that warming temperatures may have encouraged a fatal fungal outbreak.

Other species are so exotic that they've been spotted only fleetingly and haven't been seen again. Take the case of the Turkestanian salamander, No. 7 on the top-ten list. Several specimens were collected in Central Asia back in 1909, but even those specimens have disappeared. All that survives are the drawings and descriptions.

Check out this slideshow to learn more about the top-ten list.

Searching for seemingly extinct amphibians may sound like a grim task, but recent successes in species conservation have given scientists hope that even "lost" species can be rediscovered and saved.

"The search for these lost animals may well yield vital information in our attempts to stop the amphibian extinction crisis, and information that helps humanity to better understand the impact that we are having on the planet," said Claude Gascon, co-chair of the IUCN Amphibian Specialist Group and executive vide president of Conservation International.

Protecting amphibians isn't just a good idea for the amphibians: Frogs, toads and salamanders play an important part in keeping insects at bay and recycling nutrients. They may even turn out to be a source of next-generation painkillers and other medicines. (In fact, the amphibian-killing fungus may have been transported around the world by a frog that was once exported for use in pregnancy tests.)

Conservation International has set up a Web portal that points to updates in the search for lost amphibians, which leads up to October's global Convention on Biological Diversity in Nagoya, Japan. In addition to the updates and the top-ten list, you'll find a downloadable "Wanted Alive" poster suitable for posting on a classrooms or a youngster's bulletin board.

More about species lost and found:

• Deep-sea creatures of the Coral Sea
• The top 10 new species from 2009
• Beautiful biodiversity in Brazil
• New Guinea's 'Lost World' revisited
• Indonesia's 'Garden of Eden'
• Papua New Guinea's new species
• Marine marvels from Papua New Guinea
• Biological treasures from Borneo
• Celebrities of the Celebes Sea
• 12 froggy finds from India
• Fantastic frogs from Colombia
• Aliens lurk in Antarctic depths
• The strange species of Suriname
• Vulnerable new species in Brazil
• Discoveries from Vietnam's 'Green Corridor'
• Endangered species of the Mekong Delta
• New species from Australia's coral reefs
• Thousands of new species in ocean's depths
• Hundreds of new species amid the Himalayas
• New species found Down Under .. underground
• Eight 'extinct' species found alive and kicking

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