Author: San Francisco State University
Date: December 13, 2013
Summary:
Climate Change is widely believed as the primary culprit behind the rapid decline of frog populations in the Andes Mountains. But the recent study finds that the decline in frog populations is actually the result of a deadly fungus. The habitat for the frogs is also optimal for Batrachochytrium dendrobatidis (Bd), a harmful pathogen which causes chtridiomycosis, a disease which has led the recent decline or extinction of 200 frog species worldwide. Researchers have measured temperatures at which conditions are optimal for growth and spread of Bd and found that the highland frogs' habitat lay within the range. They believe Bd was likely introduced to the Andes by human activity. Vance Vredenbrug, an associate professor of biology at San Francisco State University, who studies the impact of Bd suggests that one way to prevent the spread of the disease is to stop the transport of amphibians across borders. His research shows that some species of frogs are relatively immune to this disease while others are susceptible to it. Future research on Bd will be to learn how these species can escape the harmful effects of Bd and use that knowledge to save other amphibians.
Connection:
This article connects with our recent unit on Microbes. We learned about organisms such as fungi. We learned about different types of fungi, their functions, and the general structure of fungi. Some fungi are decomposers, some are symbionts, some are predators, and some are parasites. Batrachochytrium dendrobatidis (Bd) is a parasitic fungi which has caused large declines/extinctions of frog species. This fungal parasite is also a pathogen that causes the disease chtridiomycosis, an infectious disease among amphibians. This disease has led to great decline in populations and some extinctions in species. Some populations withstand these effects which suggests that natural selection favored the traits which were immune to the harmful effects of the disease.
Does the effects of climate change still contribute a little bit to the frogs' decline?
ReplyDeleteDoes Vance Vredenbrug's research show which gene the frogs have that are immune to Bd and which gene the other frogs don't have?
ReplyDeleteThere has been no identification of a certain gene that some frogs possess that makes them immune to Bd.
DeleteOn the website below, there are suggestions to what other traits that some frogs have that makes them immune to Bd. (Ex. production of poison glands in the skin)
http://www.amphibianark.org/the-crisis/chytrid-fungus/
Yes, the climate change has been found to contribute to frog declines in lowlands, where Bd poses less of a threat to them. An experiment was conducted where researchers would put frogs in a water bath and gradually increased the temperature of the water. Frogs from the highlands were able to handle the temperature change which implied that this wasn't the primary cause of their decline, yet frogs from the lowlands were found to be overwhelmed by the temperature change.
ReplyDeleteHere is a quote from one of the researchers:
"The frogs in the highlands will not suffer from climate change anytime soon, but they're doomed because of the fungus, whereas the frogs in the lowlands are shielded from the fungus, but they're going to be toasted, because it's too hot," study researcher Alessandro Catenazzi