(full paper is archived in the Miller Library)
Title: Color morphology in Pisaster ochraceus along the
central California coast
Student Author(s): Richardson, Jill T.
Faculty Advisor(s): Pearse, John
Location: Senior Thesis UC Santa Cruz
Abstract: This paper considers the frequency of color morphology between the north and south ends of bay-shaped regions along the central California coast, and its relationship to size in the case of the seastar Pisaster ochraceus. The color variation in this seastar includes yellow, orange, brown, and purple. For the purposes of this paper, surveyed seastars were categorized as either orange or purple. The results of the survey indicate that there is no significant difference in the frequency of color morphology between the opposite ends of bay-shaped regions. Arm length and diameter were used as indices of size. The resulting measurements were used to compare color morphologies to size within a site located in the investigated bay-shaped regions. This comparison also yielded no significant difference between color morphologies. Lastly,morphological color data from a 1951 investigation of this seastar was compared to data collected for this project to detect any changes or trends with regard to color morphology frequency. The results were that no significant differences exist. It is therefore, concluded that these patterns are best explained by current marine ecological paradigms.