African Clawed Frog Responsible for Killing Hundreds of Amphibians
Scientists have been aware of the chytrid fungus infection that only afflicts amphibians for years. Since this infection has killed so many amphibians, such as frogs and salamanders, research into this infection has been primarily focused on discovering ways to prevent and protect these species from this deadly fungus. In a new study, however, researchers took a different approach and decided to pinpoint possible origins for this fungus. By understanding how it managed to spread could help researchers find ways of slowing it down and eventually controlling it from killing more animals. The research team, headed by Vance Vredenburg, a conservation biologist from San Francisco State University, was able to successfully link the chytrid fungus to the African Clawed Frog.
Vredenburg and his team analyzed 201 preserved frog species samples from African and California. These frogs, which included the African Clawed Frog, were from the time span of 1897 to 2010. Based from these samples, the researchers were able to confirm that the spread of the chytrid fungus was caused by the spread of the African Clawed Frog, which was a carrier of this fungus. In the 1930s to the 1950s, the African Clawed Frog was transported throughout the world because the species was being used as lab animals to help create human pregnancy tests. Aside from this, the frog was also very popular in the international pet trade. Through these two main factors allowed a lot of these frogs to enter and live in new ecosystem, subsequently spreading the chytrid fungus to the amphibians in the surrounding areas. The chytrid fungus infects the skins of the amphibians, making breathing difficult. It also ruins the electrolyte balance and can cause cardiac arrest.
"It's the single biggest threat to vertebrate diversity in the world," Marm Kilpatrick, a disease ecologist at the University of California, Santa Cruz who was not a part of the study, said. "It did a really huge number on an entire genus of frogs in Central America." Kilpatrick also believes that this fungus caused the extinction of the Harlequin frog and endangered California's mountain yellow-legged frog. The researchers noted that the African Clawed Frog is not the only culprit. According to their study, the African Bullfrog, used in cuisines, also carries the infection. These frogs were shipped internationally as well.
The study was published in the journal PLoS ONE.