(full paper is archived in the Miller Library)
Title: Infection mechanism and relationship of the parasitic red alga, Erythrocystis saccata (Ceramiales, rhodomelaceae) to its host
Student Author(s): Kohatsu, Keith
Faculty Advisor(s): Abbott, Isabella
Location: Final Papers Biology 175H
Date: June 1980
Keywords: symbiosis at the seashore
Abstract: Carpospores and tetraspores of Erythrocystis adhered preferentially to the trichoblasts of Laurencia. Infection of apical pits appeared to result from fortuitous attacment of spores to the proximal end of trichoblasts and extension of a unicellular rhizoid into the pit. No spore motility was observed. Infection rates in culture were approximately 30% for Laurencia collected at Stillwater Cove and Hopkins Marine Station, both areas in Monterey County, California. It is notable that the Laurencia at Hopkins is not infected by Erythrocystis in the field. In a survey of Laurencia pacifica from Stillwater Cove, it was found that up to 90% of the pits were infected by Erythrocystic germlings. Male, female and tetrasporophyte Erythrocystis occurred in the ratio of 1:1:3. Erythrocystis thalli (>1mm) predominated in the apical pits. The mean lengths of thalli from four locations on the Laurencia were significantly different (P < .05): 1*>2*>2*A>3*.