Amphibian extinction may be worse than thought
Amphibian extinction may be worse than thought
October 31, 2007
Amphibian extinction rates may be higher than previously thought, according to new DNA analysis that found more than 60 unrecognized specie in the Guiana Shield of South America.
Writing in PLoS ONE, a team of scientists warned that the number of amphibian species have been greatly underestimated. They estimate that there may be 170 to 460 unrecognized frog taxa in Amazonia-Guianas region alone and up to a total of 4400 species in South America.
The researchers say their work shows the urgent need to catalog biodiversity before it disappears.
“As a consequence of the underestimation of the number of frog species, the global amphibian decline detected especially in the Neotropics may be worse than so far realised,” write the authors. “Indeed, we cannot know how many “species” instead of “populations” have already disappeared or are disappearing, and the situation is particularly acute in the tropics.”
A previously unknown species of toad, possibly of the Atelopus genus, discovered during a Conservation International-led expedition in Suriname’s Nassau plateau. Atelopus toads have been particularly affected by the deadly chytrid fungus. Photo © Paul Ouboter
“The rapid identification and recognition of new species may exacerbate an organism’s threat status because it can result in the subdivision of a once widespread species into numerous species, each with a smaller and, hence, a more precarious distribution. Nevertheless, it is obviously better to know the state of biodiversity threat than to be ignorant of the mammoth changes in global amphibian diversity that we are witnessing,” the continue.
Amphibians — cold-blooded animals that include frogs, toads, salamanders, newts and caecilians — are dying in huge numbers all over the planet: the Global Amphibian Assessment, a comprehensive status assessment of the world’s amphibian species, reports that one-third of the world’s 5,918 known amphibian species are classified as threatened with extinction and more than 170 species have likely gone extinct since 1980. While scientists have yet to find a smoking gun, climate change, pollution, and the emergence of a deadly and infectious fungal disease, which has been linked to global warming, are the leading suspects for the observed decline.
Citation: Fouquet A, Gilles A, Vences M, Marty C, Blanc M, et al (2007) Underestimation of Species Richness in Neotropical Frogs Revealed by mtDNA Analyses. PLoS ONE 2(10): e1109. doi:10.1371/journal.pone.0001109
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