Thursday, October 16, 2014

Chytrid in Virginia amphibians

Chytrid is a pretty bad thing if you're an amphibian. It's an aquatic fungus that often hooks onto and spreads throughout creatures such as frogs, salamanders, etc. It is one of the main causes of amphibious deaths! But how does this stack up for Virginian amphibians?

Due to the conditions in chytrid's makeup, drier habitats and habitats with different temperatures than chytrid thrives in have a lower chance to infect amphibians. In the eastern part of North America, chytrid has been found in 48 species of amphibians, but infections vary due to the fact that in the summer, it's too hot for the fungus, and in the winter, it's too cold. Cooler, shaded habitats have more prevalent infections, as does the presence of frogs and toads, particularly Green Frogs. Studies were done on whether or not Eastern Newts, American Bullfrogs, Spring Peepers, and American Toads had chytrid and how intense the infection was.

Ah, the many uses of cotton swabs! During the studies, swabs were used to investigate for chytrid in said amphibian species, with adult newts, adult peepers, juvenile bullfrogs, but because the bullfrogs varied in size, it was investigated whether Snout-to-vent length affected chytrid infections. Before swabbing for infections, the study environment was sterilized to prevent other infections entering the amphibians used. The amphibians were rinsed in containers holding sterilized water and of course, the amphibians. Other examinations on two species of frog show that chytrid infections are generally on the chest, front legs, and hind legs.

Two Spring Peeper sites-Airport Pond and Kentland Farm Pond were excluded as all individuals were not infected. Toads also weren't infected. All of the species that were swabbed except for American Toads had some level of infection. The highest levels of infection were in peepers, the next highest in bullfrogs. Low levels of infection were common, especially in bullfrogs and newts. All sizes of bullfrogs were equally likely to be infected and infection intensity was fairly low among them. Chytrid has been detected in a bit over half of the amphibian species in the Eastern USA, and most frogs and salamanders have some vulnerable individuals and some resistant individuals. But due to lack of infection in the two mentioned ponds for spring peepers and in toads, when previous studies showed that they had infection, showed that said populations had resistance to the disease.

Hughey, Myra, Becker, Matthew, Walke, Jenifer, Swartwout, Meredith, Belden, Lisa. "Batrachochytrium dendrobatidis in Virginia Amphibians:Within and Among Site Variation in Infection" Herpetological Review, 2014, 45(3).

No comments:

Post a Comment