Masters Theses

Date of Award


Degree Type


Degree Name

Master of Science


Animal Science

Major Professor

Helen L. Ward

Committee Members

Arthur C. Cole, A. W. Jones


(Summary) A brief discussion of the phylum Acanthocephala is given in the introduction to this study.

Tests were conducted on the effects of the pH of the rewetting solution, temperature, and storage time on the artificial hatching of the eggs of Macracanthorhynchus hirudinaceus, the swine thorny-headed worm.

In order to test the effects of the pH of the rewetting solution, eggs which had been stored at room temperature for periods from one to 21 days were rewetted with solutions of various pH. For experiments on effects of temperature, an equal number of slide preparations were stored at each of three temperatures, room temperature (18°-32°C.), 39°C. and 5°C. They were rewetted with solutions having a pH of 8.8 after definite numbers of days had elapsed. The effects of storage time were observed by rewetting groups of slides, which had been stored from one to 21 days, with solutions having the same pH.

A solution with a pH of 8.8 was found to induce the highest percentage of hatching when used as a rewetting agent on desiccated eggs which had been stored at room temperature.

When a solution having the optimum pH of 8.8 was used to treat dried eggs, those stored for different periods of time at 39°C. showed the largest percentage of hatching. Percentages of hatchings only slightly lower than those determined at 39°C. were recorded for slides kept at room temperature. Eggs stored at 5°C. showed low viability when rewetted with a solution of a pH of 8.8.

Results obtained indicate that the number of hatchings decreases as the period of storage increases, after one day. Slides kept at room temperature for a period of 14 days showed fewer hatchings than the ones stored for seven days. The slides stored for 21 days had a much lower percentage of hatching than those kept for 14 days. No hatchings were observed after a storage period of 40 days at room temperature.

A discussion of the relationship of the experimental factors to conditions involved in natural hatching of eggs is given.

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