Publication Date


Document Type


First Advisor

Zellen, Bruce von

Degree Name

M.S. (Master of Science)

Legacy Department

Department of Biological Sciences


Trematoda--Illinois--De Kalb County; Temperature--Physiological effect; Fishes--Illinois--De Kalb County; Parasites--Fishes; Posthodiplostomum minimum Hoffman


The effect of temperature upon the course of infection, sexual maturation, and fecundity of Posthodiplostomum minimum minimum in the domestic chick was determined by acclimating groups of Notropis cornutus (common shiner) from 5 to 30 C at 5 C intervals in the laboratory. Infection rates in N. cornutus were analyzed monthly (July through December 1980) in terms of incidence and intensity of infection for each age group. Temperature did not influence the infectivity of P. minimum minimum. In general, adults were recovered from the anterior portion of the duodenum 3 to 8 days after infection and were capable of remaining in the domestic chick for at least 18 days. Adult £. minimum minimum from the 25 and 30 C groups exhibited sexual maturation at 27 h post-inoculation, while those recovered from the 5 to 20 C groups were not found to be sexually mature until 32 h. Egg production by adult minimum minimum was shown to be temperature dependent with the optimum being 25 C. Egg passage in all chicks followed a similar pattern, with patency occurring 2 days after infection and peak numbers of eggs being recovered 3 to 5 days later. The estimated rate of egg production/fluke/100 ml fecal suspension on day 1,3, 5, 8, and 10 for each experimental temperature group tended to increase while the mean number of flukes on each of these days decreased. Thus, fewer flukes were producing more eggs. The largest eggs were recovered from the 20 C group, whereas the smallest were from the 30 C. A total of 1873 fish, representing 19 species and 5 families was examined for metacercariae of P. minimum. Members of the Cyprinidae were most abundant and heavily infected with much interspecies variation. Etheostoma flabellare (fantail darter) was the only member of the Percidae infected with this parasite and represents a new host record. Incidence and intensity of infection increased with increasing age and size of N. cornutus. Young-of-year N. cornutus became infected in August with intensity of infection reaching a maximum in December. During this period mean length and weight steadily increased, which indicates no apparent retardation in the early growth rate from being infected. Heavy infestation apparently does not cause sterility in N. cornutus because young-of-year fish constituted the greatest majority of the sample.


Includes bibliographical references.||Includes illustrations and a map.


53 pages




Northern Illinois University

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