Daphnia magna
August 29, 2011

Newly Discovered Zooplankton Species Could Save Amphibians


Oregon State University (OSU) researchers have discovered a breed of freshwater zooplankton that they say can help combat a fungus that has been devastating amphibian populations around the world.

According to the International Business Times, this particular species of zooplankton is known as Daphnia magna, a variety of aquatic flea from the genus Daphnia.

They say that these organisms "could provide a desperately needed tool for biological control of the deadly fungus whose impact, one researcher has called, 'the most spectacular loss of vertebrate biodiversity due to disease in recorded history.'"

The fungus in question, B. dendrobatidis, has been dubbed a "chytrid" fungus that can disrupt electrolyte balance and lead to fatal cardiac arrest in its amphibian hosts, officials from OSU said in a press release.

"There was evidence that zooplankton would eat some other types of fungi, so we wanted to find out if Daphnia would consume the chytrid fungus," OSU doctoral student Julia Buck, the study's lead author, said in a statement. "Our laboratory experiments and DNA analysis confirmed that it would eat the zoospore, the free-swimming stage of the fungus."

"We feel that biological control offers the best chance to control this fungal disease, and now we have a good candidate for that," she added. "Efforts to eradicate this disease have been unsuccessful, but so far no one has attempted biocontrol of the chytrid fungus. That may be the way to go."

Their findings were published in the August 25 edition of the journal Biodiversity and Conservation. The study was supported in part by the National Science Foundation (NSF).

Buck believes that the chytrid fungus, which was first identified in 1998, does not need to be completely destroyed to prevent fatality in the amphibians. Rather, she believes that experts can use biological controls to simply reduce the density of the agent in order to keep it from being fatal.

The disease caused by the fungus has been identified as chytridiomycosis, and according to the OSU press release, it "has been documented to be destroying amphibians around the world," with some experts believing that as many as one-third of the world's amphibians are currently threatened by the condition.

"Its impact has been severe and defied various attempts to control it, even including use of fungicides on individual amphibians," the university added in their statement.


Image Caption: Researchers have confirmed that this zooplankton, Daphni magna, will eat a deadly fungus that is devastating amphibian populations around the world. It may provide a new biocontrol agent to help address this crisis. Credit: Oregon State University


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