Chytridiomycosis Gerri Jesse RARE FROGS BEAR THE BRUNT OF CHYTRID’S EFFECTS. FOR EXAMPLE THIS IS A BANDED HORNED TREE FROG

Chytridiomycosis The Chytrid fungus Batrachochytrium dendrobatidis also known as Bd, is responsible for morbidity, mortality, and extinction of species. Chytridiomycosis is a fungal-animal parasite, first identified in 1998 as a disease causing infection in amphibians. Amphibian populations have been declining for over 30 years. THIS DECLINE CORRELATES WITH THE PRESENCE OF CHYTRID BD. THE CONNECTION HAS BEEN SUPPORTED BY DNA SEQUENCE DATA.

Healthy Vs. Infected FRAMES C AND F WERE NOT IDENTIFIED OTHER THAN HEALTHY TOP PHOTOS, INFECTED BOTTOM. COULD BE SHOWING NORMAL SKIN CELLS AND INFECTED RESPECTIVELY. THE EARLIEST CLINICAL SIGN IN DENDROBATID FROGS IS EXCESSIVE SHEDDING OF SKIN.

Chytrid Infection Results Like us, frogs need healthy balances of electrolytes to keep the heart pumping. Amphibians absorb electrolytes through their skin. Chytrid causes their cardiac systems to malfunction in tandem with their falling electrolytes. Changes in sodium and potassium basically leads to a failure of the electrical system. Exactly how the fungus interferes with electrolyte transport is unknown. Researchers suspect it’s the result of direct cell damage, or the release of a fungal toxin. LIKE US, FROGS NEED HEALTHY BALANCES OF ELECTROLYTES TO KEEP THE HEART PUMPING. AMPHIBIANS ABSORB ELECTROLYTES THROUGH THEIR SKIN. CHYTRID CAUSES THEIR CARDIAC SYSTEMS TO MALFUNCTION IN TANDEM WITH THEIR FALLING ELECTROLYTES. CHANGES IN SODIUM AND POTASSIUM BASICALLY LEADS TO A FAILURE OF THE ELECTRICAL SYSTEM. EXACTLY HOW THE FUNGUS INTERFERES WITH ELECTROLYTE TRANSPORT IS UNKNOWN. RESEARCHERS SUSPECT IT’S THE RESULT OF DIRECT CELL DAMAGE, OR THE RELEASE OF A FUNGAL TOXIN.

The Chytridiomycota are characterized by their production of motile, flagellate zoospores. They are mainly saprophytic, although they include some notable parasites, such as BD (Batrachochytrium dendrobatidis). THESE PARASITES ALSO FOUND IN THE RUMENS OF RUMINANT MAMMALS WHERE THEY ENABLE THEM TO DIGEST CELLULOSE. THEY ARE COENOCYTIC (LACKING SEPTA). THEY ARE USUALLY UNICELLULAR AND PRODUCE RHIZOIDS INSTEAD OF TRUE MYCELIA

As a fungus the chytrid reproduces asexually forming motile spores that are flagellated. They require water to disperse. Life cycle of Chytrid Chytridiomycota is a division of the Fungi kingdom, containing only one class, Chytridiomycetes.

Global spread of Chytrid RED SHOWS WHERE CHYTRID FUNGUS IS ASSOCIATED WITH MORTALITIES – YELLOW IS NOT ASSOCIATED WITH MORTALITIES.

Terrestrial hibernating species have a lower rate of infection than aquatic hibernators. Temperature is an influencing factor in the rate and severity infection in anurans. 73.4 degrees Fahrenheit optimal temperature for Bd growth. Global warming is a factor in the spread. Many diseases are expected to become more lethal, or spread faster as the Earth warms. The relatively high infection rate in species that are not documenting die-offs could suggest that there are undetected losses, or Bd is endemic, or the species may becoming resistant to the lethal level. Climate also plays a role in preventing lethal infection levels.

Thermo-regulating behavior may allow frogs to raise their body temp Thermo-regulating behavior may allow frogs to raise their body temp. to levels that slows the fungal growth. Basking in the sun during rainy, cooler weather could allow sufficient thermal setbacks to the pathogen. Newly metamorphed are more susceptible than larger frogs. Variables in Bd are complex, especially of temperature, phylogeny of species, and hibernating choice. THE BASKING WITH OUR LOCAL CLIMATE IS WHAT MAY BE ALLOWING THE SURVIVAL OF OUR LOCAL GUYS. NOTE THAT DEAD METAMORPHIC ANURANS COULD BE EASY TO MISS – NOT RECORDED THEN.

YOU CAN HELP! It is pertinent to note that the regulation of amphibian trading may not be sufficient in preventing all trade-linked spread of the disease. The movement of infected habitat material (such as water, mud or soil containing the fungus) in non-amphibian trade industries may also spread the disease. TO PREVENT INTER-WETLAND TRANSFER OF INFECTED MATERIALS, RINSE BOOTS AND EQUIPMENT WITH 5% BLEACH BEFORE ENTERING EACH WETLAND.

Works Cited Jerry R Longcore, Joyce E Longcore, Allan P Pessier, and William A Halteman. "Chytridiomycosis Widespread in Anurans of Northeastern United States. " Journal of Wildlife Management  71.2 (2007): 435-444. Research Library, ProQuest. Web.  10 Feb. 2011. J. Alan Pounds, Martín R. Bustamante, Luis A. Coloma, Jamie A. Consuegra, Michael P. L. Fogden, Pru N. Foster, Enrique La Marca, Karen L. Masters, Andrés Merino- Viteri, Robert Puschendorf, Santiago R. Ron, G. Arturo Sánchez- Azofeifa, and Christopher J. Still. "Widespread amphibian extinctions from epidemic disease driven by global warming. " Nature  439.7073 (2006): 161. Research Library, ProQuest. Web.  10 Feb. 2011. Peter H. Raven, (et al.). Biology 8th Edition. The McGraw-Hill Companies, Inc., New York, NY. 2008. Page 618. “Pathogenesis of Chytridiomycosis, a Cause of Catastrophic Amphibian Declines.” Jamie Voyles, Sam Young, Lee Berger, Craig Campbell, Wyatt F. Voyles, Anuwat Dinudom, David Cook, Rebecca Webb, Ross A. Alford, Lee F. Skerratt, Rick Speare. Science, Vol. 326 No. 5952, October 23, 2009 Wired Science, http://www.wired.com/images_blogs/wiredscience/2009/10/chytrid- frog.jpg. Accessed 02/12/11.