(full paper is archived in the Miller Library)
Title: Environmental modulation of spontaneous body contractions in the ascidian Ciona intestinalis
Student Author(s): Gibb, E.N.
Faculty Advisor(s): Abbott, Don P.
%E Gilly, William
%E Baxter, Charles
Location: Final Papers Biology 175H
Date: June 1981
Abstract: Specimens of Ciona intestinalis were observed in the lab and in their natural habitat for evidence of spontaneous contractions. In the laboratory oxygen tension and temperature were varied to induce spontaneous contraction modulation. It was found that Ciona intestinalis contracts at an average rate of 6.3 times/h at 15-15.5 degrees C in nature. Intermediate levels of oxygen tension have no effect on contraction rate but increasing temperature increases contraction rate. 3 contraction types can be isolated in Ciona intestinalis (cross-oral, cross-atrial, and both siphons). At higher contraction rates more cross-oral and fewer "both" contractions occur. Observations at high contraction rates indicate that contraction durations occur between 10-15 sec with little variation.