Tag Archives: frogs

Amphibians in a vise: Climate change robs frogs, salamanders of refuge

By hightailing it to nearby ponds and shallow waterways, frogs and salamanders have – until now – had a way to evade exotic trout introduced to the West’s high-mountain lakes for recreational fishing.

A warming climate, however, will dry up some of the places where amphibians and their young have found refuge. Researchers in the May 1 issue of Frontiers in Ecology and the Environment write about this challenge and a novel combination of tools that could help land managers, biologists, fishing enthusiasts and other citizens weigh where amphibians are in the most need of help and guide plans for possible fish removals from selected lakes. (more…)

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Common Antifungal Drug Decreases Tumor Growth and Shows Promise as Cancer Therapy

AUSTIN, Texas — An inexpensive antifungal drug, thiabendazole, slows tumor growth and shows promise as a chemotherapy for cancer. Scientists in the College of Natural Sciences at The University of Texas at Austin made this discovery by exploiting the evolutionary relatedness of yeast, frogs, mice and humans.

Thiabendazole is an FDA-approved, generic drug taken orally that has been in clinical use for 40 years as an antifungal. It is not currently used for cancer therapy.

Hye Ji Cha, Edward Marcotte, John Wallingford and colleagues found that the drug destroys newly established blood vessels, making it a “vascular disrupting agent.” Their research was published in the journal PLoS Biology. (more…)

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Global Bullfrog Trade Spreads Deadly Amphibian Fungus Worldwide

ANN ARBOR, Mich.— The global trade in bullfrogs, which are farmed as a food source in South America and elsewhere, is spreading a deadly fungus that is contributing to the decline of amphibians worldwide, according to a University of Michigan biologist and his colleagues.

Amphibian populations are declining worldwide at an alarming rate, and the spread of the deadly chytrid fungus is believed to be a contributing factor. The fungus infects the skin of frogs, toads and salamanders.

In a study to be published in an upcoming edition of the journal Molecular Ecology, University of Michigan evolutionary biologist Timothy James and his colleagues examine the role of bullfrog farming in spreading the chytrid fungus between the forests and frog farms of Brazil and then to the United States and Japan. (more…)

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Ribbeting Research

Studies of frogs may lead to better hearing aids

When Mark Bee talks to his 106-year-old grandmother alone, her two enormous hearing aids enable her to understand him well.

“But at a table at Thanksgiving, with everybody talking, the devices don’t do well,” says Bee, an associate professor of ecology, evolution and behavior at the University of Minnesota.

Her difficulty in a noisy situation is called the cocktail party problem, after the background babble that stymies many hearing-impaired people trying to pick out individual voices at a party. But in ponds all over the world, frogs handle a similar problem, and Bee hopes to learn enough about how they do it to put the principles to work helping people like his grandmother. (more…)

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Frogs’ Amazing Leaps Due to Springy Tendons

*The secret to frogs’ superlative jumping lies in their tendons. Researchers at Brown University, filming frogs jumping at 500 frames per second with special X-ray technology, show that the frog’s tendon stretches as it readies its leap and then recoils, much like a spring, when the frog jumps. The finding could explain how other animals are exceptional leapers. Results appear in Biology Letters.*

PROVIDENCE, R.I. [Brown University] — Some species of frogs and many other animals are able to jump far beyond what appear to be their capabilities. The trained contestants in the frog-jumping competition in Calaveras County, Calif., come to mind, but even ordinary frogs can leap several times farther than their physiology would seem to allow.

“Muscles alone couldn’t produce jumps that good,” said Henry Astley, who studies the biomechanics of frog jumping at Brown University. (more…)

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National Zoo and Partners First to Breed Critically Endangered Tree Frog

Although the La Loma tree frog, Hyloscirtus colymba, is notoriously difficult to care for in captivity, the rescue project is the first to successfully breed this species. Image credit: Brian Gratwice, Smithsonian's National Zoo

As frogs around the world continue to disappear—many killed by a rapidly spreading disease called chytridiomycosis, which attacks the skin cells of amphibians—one critically endangered species has received an encouraging boost. Although the La Loma tree frog, Hyloscirtus colymba, is notoriously difficult to care for in captivity, the Panama Amphibian Rescue and Conservation Project is the first to successfully breed this species.

“We are some of the first researchers to attempt to breed these animals into captivity and we have very little information about how to care for them,” said Brian Gratwicke, international coordinator for the project and a research biologist at the Smithsonian’s National Zoo, one of nine project partners. “We were warned that we might not be able to keep these frogs alive, but through a little bit of guesswork, attention to detail and collaboration with other husbandry experts—we’ve managed to breed them. The lessons we’re learning have put us on target to save this incredible species and our other priority species in Panama.”  (more…)

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2 new frog species discovered in Panama’s fungal war zone

Trying to stay ahead of a deadly disease that has wiped out more than 100 species, scientists at the Smithsonian Tropical Research Institute continue to discover new frog species in Panama: Pristimantis educatoris, from Omar Torrijos National Park, and P. adnus from Darien Province near the Colombian border.

(more…)

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