Date of Award


Document Type


Degree Name

Master of Science (MS)




Analyses of the fish, parasites and water of four North Dakota rivers in the Missouri River and Hudson Ba.y drainages were made. A total of 277 fish representing 13 families was. collected from June 28 through November 2, 1975 from 19 sampling stations on the Missouri River below Garrison Dam, the James River above Jamestown Reservoir, the Sheyenne River above Lake Ashtabula and the entire Wild Rice River. The abiotic factors of water temperature, dissolved oxygen, chlorides, nitrates, nitrites, sulphates, orthophosphates, pH and turbidity were determined for each sampling station using Standard Methods or Hach procedures. Of the fish examined 80% were infected with parasites. Forty-six species were identified and eight parasites were identified only to generic level. Several parasites could not be placed in any taxon below class. Seven forms were reported from new hosts and 24 parasites were reported from North Dakota for the first time. A checklist of the fish parasites of North Dakota, based on published data, was expanded to include new forms reported herein. Differences between parasite faunas of rivers were attributed to host specificity, number of fish autopsied in each river and number of collecting stations per river. The possible restriction in the northerly distribution of Lernaea cyprinacea was attributed to temperature. A reduction in ectoparasites in poorly oxygenated water was noted. Using multiple linear regression techniques to separately analyze nine fish species, general increases in number of parasite species and parasite numbers were found with st aging. A general reduction in parasite numbers per gram of fish with imrease in host age was noted. Analyses of coefficient of condition (K) n't, respect to parasite burdens of four fish species indicated significant :orr Nations for only Cyprinus carpio.