Parasites of Fishes of Oahe and Big Bend Reservoirs, South Dakota

During the summer and fall of 1964, 292 fishes collected from Oahe and Big Bend Reservoirs in central South Dakota were examined for parasites. Sixty-five percent of the 18 different species of fishes examined were parasitized by at least one of the 16 species of parasites found. Seventy-five percent of the 162 fishes examined from Oahe Reservoir were found to be infected with at least one species pf parasite, and 54 percent of the 130 fishes examined from Big Bend Reservoir were infected. The fishes found to be harboring the largest number of species of parasites were the black bullheads and the yellow perch. Perhaps one reason for this is that there were more black bullheads and yellow perch examined than any other species. Another reason could be that the condition present in the reservoirs are best suited for the life cycles if the parasites infecting the bullheads and perch. The purpose of this study is to determine the most prevalent fish parasites occurring in the Oahe and Big Bend Reservoirs. A comparison is made between the parasites found in the Oahe and those found in Big Bend, and also between seasonal differences of the parasitism in some species of fishes found in both reservoirs