What is the yellow perch parasite (Heterosporis sp.) and has it been found in Indiana?
The parasite Heterosporis sp. has been found primarily in yellow perch in the Eagle River Chain of Lakes in Wisconsin and Leech Lake in Minnesota. The parasite is also known from eels in Japan and Taiwan, in aquarium fish in France and Germany, and may also infect walleye. This microsporidian parasite does not affect people. The infection shows no visible signs on the outside of the fish. It causes the flesh to have a cooked or freezer burned appearance (white areas) of tissue inside the fish. The infected muscle cells reduce the quality and change the texture of the fillet. The parasite’s life cycle is only partially known. As infected fish die and decompose, spores are released into the water and are swallowed by other fish. Muscles just behind the head seem to be infected first. The infection then spreads throughout the entire body. To assist in controlling this disease, report any suspected case to the nearest DNR office and keep the fish refrigerated until a biologist can inspect
