(full paper is archived in the Miller Library)
Title: Biogeography of Symbiodinium in Anthopleura
elegantissima on the California coast
Student Author(s): Sanders, Jon
Faculty Advisor(s): Somero, George
Location: Final Papers Biology 175H
Date: June 2005
Abstract: The algal-cnidarian symbiosis is a useful system for investigating patterns of selection and adaptation different from standard single-organism models. Current research, mostly focused on tropical ecosystems, indicates that the host/symbiont relationship can be flexible: hosts can house different symbionts under different conditions. This flexibility may allow for adaptation of the entire symbiotic system (holosymbiont) rather than the individual players. However, less is known about the behavior of temperate algal-cnidarian systems. In this study, I examine the fine scale dinoflagellate symbiont biogeography in the temperate sea anemone Anthopleura elegantissima, as first observed by LaJeunesse and Trench (2000). Restriction Fragment Length Polymorphism (RFLP) analysis of small subunit (SSU) ribosomal DNA indicates a complex transition zone from Cape Mendecino (N40º 24', W124º 23') to Salt Point (N38º 33', W123º 20'), with anemones to the north harboring Symbiodinium muscatinei and those to the south co-harboring S. muscatinei and S. californium. S. californium is present in the north and south of the transition zone, but absent from the center. A new RFLP signature was found in anemones from the center of the transition zone, suggesting the presence of a third dinoflagellate species endemic to that area.