Frogs Galore!

05/19/2009

Boophis arcanus, a new species just discovered in Madagascar/ Copyright David Vieites/CSIC

The planet may be swimming in undiscovered fungi or bacteria or lowly invertebrates, but it’s rare to discover a new vertebrate species these days. But biologists just discovered somewhere between 129 and 221 new frog species in Madagascar, which doubles the known number of amphibian species in the island country off the western coast of Africa. Political instability puts these species at risk.

Just as Australia has unique marsupials found nowhere else in the world, kangaroos, koalas, platypus and the like, the island country of Madagascar has many endemic species, found nowhere else in the world, because of its 160 million-year isolation from mainland Africa. Lemurs are probably the most well-known endemic species from Madagascar. There are more than 30 lemur species, primates found only on the island.

A team of biologists from the Spanish Scientific Research Council (CSIC), led by David Vieites, conducted a long-term assessment of frog species across the country. “In every expedition we find something interesting, but we needed to have an overview of the whole fauna to really understand how many species are there,” says Vietes. “It took us 10 years, and we will continue working on this as there are more remote areas to explore.”

The variability around number of species discovered relates to the fact that, since these are just recently discovered frogs, some that look different may be the same species with different morphs. Likewise, sometimes species that look similar are different species that do not interbreed. “There are three basic components necessary to [identify] frogs: genetics, bioacoustics and morphology,” explains Vieites. The biologists caught the frogs mostly by hand, recorded details about their size, shape, color and other identifying characteristics, took tissue samples for genetic analysis, and recorded their calls – bioacoustics. “We gathered those data for most specimens and these are the base to describe them as new species. As you can imagine, only by having an overview of the whole amphibian fauna we can do this successfully, but this took us a decade.”

The biologists found dozens of new species even within the most commonly visited and studied national parks in the country, Ranomafana and Mantadía/Analamazaotra. Forest destruction on Madagascar has occurred at an alarming rate, with over 80% of the historic rainforests already gone. Because of political instability, individuals and companies alike sometimes illegally log forests, even within protected parks.

A hotbed of biodiversity, only one of Madagascar’s previously known 244 species of frogs is found elsewhere. In their recent paper, just published in the Proceedings of the National Academy of Sciences, Vieites and colleagues write, “This case study suggests that worldwide tropical amphibian diversity is probably underestimated at an unprecedented level and stresses the need for integrated taxonomic surveys as a basis for prioritizing conservation efforts within biodiversity hotspots.” Compare these numbers – somewhere around 400 – to the fact that Germany has only 20 frog species. Texas, slightly larger than Madagascar, has 52 frog species. Viva biodiversity!

Learn more about the "Vanishing Frog" from animal expert, Jeff Corwin.

Find out how to create a tadpole aquarium in your own backyard.