Parasites in Yellow Perch (Perca flavescens) and Rock Bass (Ambloplites rupestris) in Northern Michigan: A comparative study of the time periods 1940-1942 and 2006.

Abstract

In 1940 at the University of Michigan Biological Station, located on the southern shore of South Fishtail Bay on Douglas Lake in Pellston, Michigan, records began to be compiled in reference to host cards completed for dissected specimens. A variety of parasitic organisms were included in these records, ranging from helminthes to protozoans to parasitic arthropods. The following study, conducted by Aaron Tavalire with research partner Bryan J. Cohen, compares the prevalence of parasite species recorded in the 1940-1942 time period to a collection of data sets and specimens gathered in the summer of 2006, during a three week period beginning July 15th and ending August 7th. Parasites observed in Perca flavenscens (yellow perch) were found to be significant in length (p<0.01), weight (p<0.002) and life stage (p<0.04). P. flavescens parasite data was not significant for host sex (p>0.05). Parasites of Ambloploites rupestris were not found to be significant for length, mass, life stage, or host sex (p>0.05). In present day samples, there was a larger abundance of parasitic organisms present in P. flavescens than that of A. rupestris (p<0.001), due to the presence of Diplostomum flexicaudum in a metacercarial stage in the eyes of the fish. Specimens from 1940-1942 showed a higher prevalence of cestodes and acanthocephalans, and the 2006 data set showed a higher prevalence of trematodes than the records of 1940-42. An equal number (1) of nematodes were present in each data set.