Undergraduate Researcher

Forestry and Natural Resources

Purdue University (West Lafayette, IN)

Dr. Rod N Williams

I am currently assessing the prevalance of Ambystomatid salamander malformations in central and southern Indiana.

Statement of Problem: Global amphibian declines are resulting from a wide host of issues. One identified cause for declines is malformations. Previous studies have shown a correlation between increased agricultural runoff and the persistence of the digean trematode Ribeiroia ondatrae which is linked to causing malformations in Anurans. It is suggested that the trematode is also a cause for increased Urodele malformations. I’m working to assess Ambystomatid salamanders in Indiana to obtain a better understanding on parasite interactions. Current estimates for salamander malformations have not yet been done in the state of Indiana.
Previous Activities: In June and July of 2009 larval salamanders were sampled and assessed for malformations in eight ponds in central in southern Indiana. Salamanders were collected with minnow traps. Upon collection each salamander was identified to species, assessed for malformations, and measurements were taken for the total and snout vent lengths. If sample numbers were sufficient, 20 normal and 20 malformed salamanders were euthanized and collected for further parasite enumeration.
Current Activities: This fall, the salamanders that were collected for parasite enumeration will be cleared and stained to enhance the visualization of metacercarial cysts caused by Ribeiroia ondatrae. After the staining and dying process they will be segmented and examined using a stereo-dissecting microscope to quantitatively assess the rate of infection. Species identification is difficult using morphological characteristics, therefore to ensure proper identification of parasites a (PCR)-based diagnostic will be performed for Ribeioria spp.
Research