Publication Date


Advisor(s) - Committee Chair

Tom Coohill, Al Fennelly, and James Parks

Degree Program

Department of Physics and Astronomy

Degree Type

Master of Science


The purpose of this investigation was to study ultraviolet radiation effects on rotifers. The rotifer studied was Philodina acuticornis odiosa Milne. Isolation cultures were used to grow the rotifers individually in separate U-plate depressions. The source of ultraviolet radiation consisted of four mercury germicidal lamps used in combination to deliver a uniform flux of 315 uW/cm2 over the sample. Five groups of rotifers, one control and four experimental groups of 96 each, were used. The rotifers used were 2-10 hours of age at the beginning of the experiment. The experimental groups were exposed to uv radiation for 3 minutes, 5 minutes, 7 minutes, 9 minutes. The mean lifetime of each of the control, 3 minutes, 5 minutes, 7 minutes, and 9 minutes irradiated groups was 20.4 days, 19.1 days, 17.1 days, 11.5 days, and 6.3 days respectively. No specific theory, nor the mechanism involved is given to explain these uv radiation effects on rotifers. From the data, it is concluded that some radiation shortens the mean lifetimes of rotifers and that there is a threshold exposure after which the survival of the rotifer changes drastically.


Astrophysics and Astronomy | Life Sciences | Physical Sciences and Mathematics