Chytridiomycosis and Its Effect on North American Anurans
Barclay Culp
General Seminar, Bio301A
4/5/16
Abstract:
Infectious diseases are an issue for many higher level organisms. One such disease is chytridiomycosis caused by the fungus Batrachochytridium dendrobatidis. This review paper seeks to introduce the reader to this organism by giving some necessary background information on the organism. In addition, the paper will discuss the symptoms of chytridiomycosis in both larval and adult anurans infected with the fungus. Anurans native to North America will be the primary focus on the animals. The susceptibility of certain anurans species will also be examined. The cause of chytridiomycosis will be examined by looking at the life cycle
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This paper will conclude discussing the ecological effects the microscopic fungus has had on …show more content…
The organism belongs to the lesser known division Chytridiomycota, the class Chytridiomycetes, and the order Rhizophydiales. The microbe lives in aquatic environments, where anurans spend much of their lives. Bd was first recognized and classified in the year 1998. Since the discovery of the fungus, it has spread to every continent except Antarctica, where anurans are not present. Kerry Krieger and Jean-Marc Hero report that the pathogen is presently known to infect 287 amphibian species and has been detected in 37 countries (6).
Symptoms of Chytridiomycosis
i. Symptoms in larval anurans
Berger et al. state Bd infects the external, keratin-containing layers of anuran skin (9036). He continues saying in tadpoles, the mouth parts are the only parts of the body possessing keratin, and therefore is susceptible to infection (9034). Rachowicz and Vredenburg state this can lead to depigmentation around the mouth, and occasionally defects in the region. They found the mouth defect in only one of the infected Rana muscosa tadpoles from their experiment. During metamorphosis, anuran skin becomes progressively more keratinized, allowing the infection to spread to other regions of the body.
Nichols et al. report one of the earliest symptoms to appear in infected anurans is anorexia, which can occur as soon as eight days after exposure to the pathogen
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