(full paper is archived in the Miller Library)
Title: Anatomical study of the hypobranchial gland of Calliostoma canaliculatum and the neuronally controlled secretion of yellow stuff (YS)
Student Author(s): Toranto, Jason
Faculty Advisor(s): Gilly, William
Location: Final Papers Biology 175H
Date: June 1998
Abstract: The channeled top snail, Calliostoma canaliculatum, releases a yellow mucous, called yellow stuff or YS, in response to perturbation and especially attempted predation from sea stars such as Pycnopodia hellantholdes (Bryan et al., 1997). The source of YS is the hypobranchial gland. Therefore, anatomical studies of this gland as well as electrical stimulation experiments, to visualize secretion from this organ, were performed. The anatomical study divulges the existence of cells that contain numerous large vesicles that appear to contain yellow stuff. Stimulation of the gland directly as well as other body sites with an electrode reveals that a one second train of brief shocks with a repeat frequency of 20Hz is sufficient to cause secretion of YS. Stimulated secretion was reversibly abolished by low Ca2+ seawater. These stimulation experiments demonstrate that the secretion of YS is under neuronal control. Finally, from the trends that were visualized in the anatomical study and from a consideration of the time course of secretion, holocrine secretion is proposed to be the method by which YS is released from the yellow cells of the hypobranchial gland.