Oceanography presented on April 23, 1.984 Title: Seasonal Relationship Between The Digestive Enzyme Activity Of Laininarinase And Ingestion Rate Of Acartia clausii

Abstract approved: The relationship between the digestive enzyme activity of laminarinase and ingestion rare of the copepod Acartia clausii at five food concentrations of Thalassiosira weissflogii were investiga-ted in a series of experiments using copepods collected from Yaquina Bay, Oregon during 1982 and 1983. Copepods were acclimated to these five food concentrations and filtered seawater for three days in the laboratory. Following this interval, 24-hour grazing experiments were performed to determine the ingestion rates of the copepods at these food concentrations. Laminarjnase activities of the copepods from all food levels and filtered seawater were determined following the conclusion of these grazing experiments. ingestion rates for Acartia clausii increased approximately linearly with food concentrations below 2.5 x urn3/ml and reached a maximum rate at food concentrations above this level. Ivlev equatio